Abstract
Introduction
Optimal delivery mode for vaginal breech birth at term remains controversial, with varying recommendations across international guidelines. This study aimed to evaluate common perceptions and outcomes associated with VBB using retrospective data, including benefits of cesarean section, maternal and neonatal risks.
Material and Methods
We conducted a monocentric, retrospective cohort study over 21 years at a German tertiary perinatal center, examining term breech deliveries. Outcomes were compared between planned cesarean section and intended vaginal breech birth, with the latter group further categorized by successful and unsuccessful vaginal breech birth attempts.
Results
Of all deliveries, 3.6% (3172) were singleton breech presentations beyond 36 weeks gestation. Among these, 2501 cases (78.8%) were planned cesarean sections, while 671 cases (21.2%) were intended vaginal breech births. Within the intended vaginal breech birth group, 524 (78%) achieved vaginal delivery, whereas 147 (22%) required secondary cesarean section. Maternal outcomes showed significant differences in blood loss (p < 0.001) and hospital stay (p < 0.001), favoring the vaginal breech birth group with lower blood loss and shorter hospital stays. However, neonatal interventions, including bag-mask ventilation and resuscitation, were significantly more frequent in the vaginal breech birth group (p < 0.001), along with increased short-term neonatal morbidity such as neonatal infections (p < 0.001), transient tachypnea (p = 0.002), and hypoxic-ischemic encephalopathy (p = 0.008).
Conclusion
The findings highlight an increase in intended vaginal breech births with a high rate of successful vaginal deliveries. Vaginal breech birth was associated with fewer maternal complications but elevated short-term neonatal morbidity. The results underscore the importance of individualized counseling and skilled provider presence when considering vaginal breech birth, supporting informed maternal choice and optimized delivery outcomes.
Keywords: breech birth, delivery mode, cesarean section, upright birth position, external cephalic version
Zusammenfassung
Einleitung
Der optimale Entbindungsmodus für eine termingerechte vaginale Geburt aus Beckenendlage wird immer noch kontrovers diskutiert. Die in internationalen Richtlinien gemachten Empfehlungen variieren. Ziel dieser Studie war eine Evaluierung der verbreiteten Auffassungen sowie den mit einer vaginalen Beckenendlagengeburt assoziierten Ergebnissen. Hierzu wurden retrospektive Daten verwendet, die auch die Vorteile einer Kaiserschnittentbindung sowie mütterliche und neonatale Risiken berücksichtigten.
Material und Methoden
Es wurde eine monozentrische retrospektive Kohortenstudie über einen Zeitraum von 21 Jahren in einem deutschen Perinatalzentrum der Tertiärversorgung zur Untersuchung von termingerechten Entbindungen in Beckenendlage durchgeführt. Die Ergebnisse von geplanten Kaiserschnittentbindungen wurden mit den Ergebnissen von beabsichtigten vaginalen Entbindungen in Beckenendlage verglichen. Letztere Gruppe wurde weiter in erfolgreiche und erfolglose Versuche einer vaginalen Entbindung in Beckenendlage unterteilt.
Ergebnisse
Von der Gesamtgruppe aller Entbindungen waren 3,6% (3172) Einlingsgeburten in Beckenendlage nach der 36. Schwangerschaftswoche. Davon waren 2501 (78,8%) geplante Kaiserschnittentbindungen, während in 671 Fällen (21,2%) eine vaginale Beckenendlagengeburt beabsichtigt wurde. In der Gruppe der beabsichtigten vaginalen Beckenendlagengeburten hatten 524 (78%) eine vaginale Entbindung, während 147 (22%) einen sekundären Kaiserschnitt benötigten. Bei den mütterlichen Outcomes gab es signifikante Unterschiede bezüglich Blutverlust (p < 0,001) und Krankenhausaufenthalt (p < 0,001), wobei die Gruppe der vaginalen Beckenendlagengeburten einen geringeren Blutverlust und einen kürzeren Krankenhausaufenthalt aufwies. Allerdings wurden neonatale Interventionen, darunter Masken-Beutel-Beatmung und Wiederbelebung, signifikant häufiger in der Gruppe der vaginalen Beckenendlagengeburten benötigt (p < 0,001), und kurzfristige neonatale Morbiditäten wie z. B. neonatale Infektionen (p < 0,001), transiente Tachypnoe (p = 0,002) und hypoxisch-ischämische Enzephalopathie (p = 0,008) waren höher.
Schlussfolgerung
Diese Ergebnisse wiesen auf eine Zunahme geplanter vaginaler Beckenendlagengeburten mit einer hohen Rate erfolgreicher vaginaler Entbindungen hin. Die vaginale Beckenendlagengeburt war mit geringeren mütterlichen Komplikationen, aber einer höheren kurzfristigen neonatalen Morbidität verbunden. Wenn eine vaginale Beckenendlagengeburt in Erwägung gezogen wird, unterstreichen diese Ergebnisse die Bedeutung einer individualisierten Beratung sowie der Anwesenheit eines erfahrenen Geburtshelfers, um die Mutter bei der informierten Entscheidung zu unterstützen und das Geburts-Outcome zu optimieren.
Schlüsselwörter: vaginale Beckenendlagengeburt, Entbindungsmodus, Kaiserschnitt, aufrechte Geburtsposition, äußere Wendung
Abbreviations
- BMI
Body Mass Index
- CS
Cesarean Section
- CTG
Cardiotocography
- ECV
External Cephalic Version
- FGR
Fetal Growth Restriction
- GA
Gestational Age
- HIE
Hypoxic-ischemic Encephalopathy
- ICU
Intensive Care Unit
- LP
Lateral Position
- NICU
Neonatal Intensive Care Unit
- PROM
Premature Rupture of Membranes
- RCOG
Royal College of Obstetricians and Gynecologists
- SP
Supine Position
- TBT
Term Breech Trial
- UP
Upright Position
- VBB
Vaginal Breech Birth
Introduction
Up to 4% of term pregnancies present in breech presentation 1 . Despite this, there is still no consensus on the optimal mode of delivery 2 3 . Until the 1990s, vaginal breech birth (VBB) was widely regarded as a safe option 4 . However, the Term Breech Trial (TBT), published in 2000, marked a significant shift in obstetric practice. Hannah et al. reported improved short-term neonatal outcomes with planned cesarean section (CS) for term breech deliveries 5 . The TBT, however, faced criticism for its methodology and applicability, resulting in variations in national guidelines 6 7 8 . In Europe, initiatives such as PREMODA in France 5 , OptiBreech in the United Kingdom 6 and FRABAT in Germany 7 , have aimed to reestablish VBB as a viable option in appropriately trained settings. In Germany, current guidelines recommend counseling women with breech babies on both CS and VBB in perinatal centers capable of offering both options 8 . In our center, VBB rates have increased since the TBT. Within the last decade, approximately 40% of breech deliveries were VBB attempts. This study retrospectively analyzed VBB data to enhance counseling for future patients.
Material and Methods
We conducted a retrospective, single-center cohort study from January 2001 to December 2021. Ethical approval was obtained from the Ethics Committee of the University of Munich (Project Number 22–065) on August 16th, 2022. The study was conducted in accordance with the Declaration of Helsinki.
Data were retrieved from the database of a German Tertiary Perinatal Center with two delivery units and approximately 3800 births annually. After excluding cases with lethal malformations, intrauterine death, and births occurring before transfer to the hospital, we analyzed all singleton breech presentations beyond 36 weeks of gestation. Mode of delivery was discussed with all pregnant women presenting with a fetus in breech position prior to the onset of labor. Apart from maternal preference for a birth mode, contraindications like fetal growth restriction (FGR) with a difference in abdominal circumference being smaller than the head circumference of more than 3 cm or fetal anomalies were checked. In our unit, there was no clear suggestion for MRI measurement of the maternal pelvis in nulliparous women. It was up to the counseling obstetrician to suggest MRI pelvimetry. Expert counseling included a detailed discussion with the patient about reasons to follow or to abandon the vaginal birth way. Maternal unfavorable conditions as previous CS, pregnancy-related or preexisting diabetes, hypertensive pregnancy disorders, and uterine abnormalities were discussed with the patient but did not automatically lead to a planned CS. The presence of an experienced obstetrician and of a pediatrician at birth was mandatory. If this was not the case, a cesarean section was performed.
All patients with a fetus in breech presentation were offered an external cephalic version (ECV), however participation in ECV was not mandatory.
Outcomes
The primary outcome was the rate of successful VBB. Secondary outcomes included both maternal and neonatal outcomes. Maternal outcomes encompassed blood loss, length of hospital stay, birth-related trauma, re-laparotomy due to bleeding, hysterectomy, postpartum ICU admission, wound healing disorders, and complications such as endometritis, deep vein thrombosis, or maternal death. Neonatal outcomes included measures of neonatal morbidity, such as infections, transient tachypnea, hypoxic-ischemic encephalopathy (HIE), hypoglycemia, hypothermia, APGAR scores, umbilical cord pH levels, birth trauma, and neonatal death.
Data sets included maternal baseline characteristics and birth outcomes, categorized by mode of delivery (successful VBB, unplanned CS after failed VBB, planned CS, secondary CS due to onset of labor before planned CS). Data was extracted from databases, with additional information from the paper-based birth register and the hospital’s internal SAP clinical system.
Statistical analysis
Descriptive statistics were presented using frequency tables, and medians with interquartile ranges were used for metric and ordinal data. Pearson’s Chi-square test and Fisher’s exact test were employed to compare categorical variables across intended birth modes. Ordinal and metric data were analyzed using the Wilcoxon-Mann-Whitney U test. An alpha error of 5% was considered, with p < 0.05 deemed statistically significant and p < 0.001 considered highly significant. A multivariable logistic regression analysis was performed to identify factors associated with successful vaginal delivery. The Kruskal-Wallis test was used to compare three or more independent groups on a continuous or ordinal dependent variable. All analyses were conducted using IBM SPSS Statistics version 29.
Results
Between January 2001 and December 2021, the LMU Perinatal Center recorded 80778 births. Among these, 3172 (3.6%) were singleton breech presentations at or beyond 36 weeks gestation, meeting our inclusion criteria. Of these, 2501 (78.8%) were planned CS, and 671 (21.2%) were intended VBB. Among the intended VBBs, 524 babies (78%) were delivered vaginally, while 147 women (22%) required unplanned CS due to factors such as pathological CTG, prolonged labor, arrest of labor, maternal exhaustion, or maternal request. These data are presented in Fig. 1 .
Fig. 1.
Flow chart of intended and actual birth mode at LMU Klinikum 2001–2021. In total, data of 3193 singletons in breech presentation with a GA ≥ 36+0 weeks were included. The groups of intended CS were subdivided in CS before and after onset of labor and intended VBB were subdivided in successful and unsuccessful VBB.
We categorized the CS group into planned cesarean deliveries and those performed after labor onset but previously planned. The planned VBB group was further divided into those who successfully delivered vaginally and those who required a secondary CS.
Over the 21-year period, 37 obstetricians managed vaginal breech births at our center. Notably, 80.5% of successful VBBs (422 out of 542) were led by ten experts, each with over ten successful VBBs during this period, with individual experience ranging from 10 to 121 successful VBBs. Obstetricians trained in VBB provided nearly continuous coverage, ensuring availability almost 24 hours a day, 7 days a week.
Maternal characteristics
In this analysis, we compared the 2501 planned CS cases with the 671 intended VBB cases. Significant differences were observed in maternal age (p = 0.01), with a lower pre-pregnancy BMI in the intended VBB group (p = 0.007). The VBB group also had a higher proportion of multiparous women (p = 0.012), with a highly significant p-value for those with a history of exclusively vaginal births (p < 0.001). Previous CS was significantly more common in the planned CS group (p < 0.001). Regarding maternal unfavorable conditions, a significantly higher rate of either pregnancy-related or preexisting diabetes (p = 0.04), hypertensive pregnancy disorders (p = 0.035), and uterine anomalies (p = 0.06) was detected in the planned CS group (see Table 1 and Table 2 ).
Table 1 Maternal characteristics regarding the intended birth mode divided in planned CS and intended VBB.
| Intended birth mode | ||||||
| Maternal characteristics | Planned CS | Intended VBB | ||||
| n = 2501 | (%) | n = 671 | (%) | Sig. | ||
| Age | 0.010 | |||||
| ≤ 21 years | 49 | (2.0) | 5 | (0.7) | ||
| 22–34 years | 1548 | (61.9) | 450 | (67.1) | ||
| ≥ 35 years | 904 | (36.1) | 216 | (32.2) | ||
| BMI before pregnancy | 0.007 | |||||
| BMI < 30 kg/m² | 2249 | (89.9) | 629 | (93.7) | ||
| BMI ≥ 30 kg/m² | 193 | (7.7) | 32 | (4.8) | ||
| Unknown | 59 | (2.4) | 10 | (1.5) | ||
| Parity | 0.012 | |||||
| 1 (this birth) | 1858 | (74.3) | 461 | (68.7) | ||
| 2 (one previous birth) | 482 | (19.3) | 153 | (22.8) | ||
| > 2 | 161 | (6.4) | 57 | (8.5) | ||
| Condition after CS | 367 | (14.7) | 8 | (1.2) | < 0.001 | |
| Status post exclusively vaginal births | 277 | (11.1) | 202 | (30.1) | < 0.001 | |
| Diabetes mellitus/Gestational diabetes | 186 | (7.4) | 29 | (4.3) | 0.004 | |
| Hypertensive pregnancy disorders | 69 | (2.8) | 9 | (1.3) | 0.035 | |
| Uterus anomaly | 201 | (8.0) | 33 | (4.9) | 0.006 | |
Table 2 Maternal characteristics regarding the intended birth mode divided in planned CS and intended VBB.
| Birth mode | |||||||||
| Planned CS | Secondary CS after spontaneous onset of labor | Secondary CS after an unsuccessful attempted VBB | Successful VBB | ||||||
| n = 1806 | (%) | n = 694 | (%) | n = 147 | (%) | n = 525 | (%) | ||
| Maternal age | ≤ 21 years | 34 | (1.9) | 15 | (2.2) | 0 | (0.0) | 5 | (1.0) |
| 22–34 years | 1115 | (61.7) | 432 | (62.2) | 91 | (61.9) | 360 | (68.6) | |
| ≥ 35 years | 657 | (36.4) | 247 | (35.6) | 56 | (38.1) | 160 | (30.5) | |
| BMI before pregnancy | BMI < 30 kg/m² | 1619 | (89.6) | 629 | (90.6) | 142 | (96.6) | 488 | (93.0) |
| BMI ≥ 30 kg/m² | 157 | (8.7) | 36 | (5.2) | 4 | (2.7) | 28 | (5.3) | |
| Unknown | 30 | (1.7) | 29 | (4.2) | 1 | (0.7) | 9 | (1.7) | |
| Parity | 1 (this birth) | 1339 | (74.1) | 519 | (74.8) | 128 | (87.1) | 333 | (63.4) |
| 2 (one previous birth) | 348 | (19.3) | 133 | (19.2) | 16 | (10.9) | 138 | (26.3) | |
| > 2 | 119 | (6.6) | 42 | (6.1) | 3 | (2.0) | 54 | (10.3) | |
| Condition after CS | 281 | (15.6) | 86 | (12.4) | 3 | (2.0) | 5 | (1.0) | |
| Status post exclusively vaginal births | 186 | (10.3) | 90 | (13.0) | 16 | (10.9) | 187 | (35.6) | |
| Diabetes mellitus/Gestational diabetes | 143 | (7.9) | 43 | (6.2) | 7 | (4.8) | 22 | (4.2) | |
| Hypertensive pregnancy disorders | 59 | (3.3) | 10 | (1.4) | 5 | (3.4) | 4 | (0.8) | |
| Uterus anomaly | 148 | (8.2) | 53 | (7.6) | 7 | (4.8) | 26 | (5.0) | |
Maternal outcomes
Maternal outcomes showed highly significant differences in blood loss (p < 0.001) and hospital stay (p < 0.001), as well as significant differences in elevated blood loss > 1000 ml (p = 0.004) and > 1500 ml (p = 0.012), and postpartum hemoglobin levels (p = 0.016) in the planned CS group. No significant differences were observed regarding birth-related trauma, re-laparotomy due to bleeding, hysterectomy, postpartum ICU stay, wound healing disorders, or complications such as endometritis, deep vein thrombosis, ileus, or postpartum depression. No maternal deaths occurred in either group (see Table 3 ).
Table 3 Maternal Outcome regarding intended birth mode divided in planned CS and intended VBB.
| Maternal Outcome | Intended birth mode | ||||||
| Planned CS | Intended VBB | ||||||
| n = 2501 | (%) | n = 671 | (%) | Odds Ratio (95%-KI) | Sig. | ||
|
E
Included criterion for composite variable ‘postpartum
maternal mortality and severe morbidity’.
‡ Cases with severe preeclampsia with ICU stay were excluded. | |||||||
| Blood loss in ml | Median (IQR) | 500 (200) | 300 (200) | < 0.001 | |||
| Elevated blood loss | > 1000 ml | 63 | (2.5) | 31 | (4.6) | 1.87 (1.21–2.90) | 0.004 |
| > 1500 ml E | 16 | (0.6) | 11 | (1.6) | 2.59 (1.19–5.60) | 0.012 | |
| Transfusion of ECs E | 11 | (0.4) | 5 | (0.7) | 1.70 (0.59–4.91) | 0.355 | |
| Hb level postpartum | Median (IQR) | 10.9 (1.6) | 11.0 (2.1) | 0.016 | |||
| ≥ 10 g/dl | 1961 | (78.4) | 469 | (69.9) | |||
| 8 g/dl > and < 10 g/dl | 473 | (18.9) | 133 | (19.8) | |||
| 6 g/dl < and ≤ 8 g/dl | 48 | (1.9) | 26 | (3.9) | |||
| ≤ 6 g/dl E | 6 | (0.2) | 3 | (0.4) | 1.98 (0.49–7.92) | 0.398 | |
| Unknown | 13 | (0.5) | 40 | (6.0) | |||
| Birth-related trauma E | 8 | (0.3) | 0 | (0.0) | – | 0.216 | |
| Definition of trauma | Urinary bladder lesion intraoperative | 6 | (0.2) | 0 | (0.0) | ||
| Uterus perforation | 1 | (0.0) | 0 | (0.0) | |||
| Electrical burn intraoperative | 1 | (0.0) | 0 | (0.0) | |||
| Cervical laceration E | 0 | (0.0) | 1 | (0.1) | – | – | |
| Re-laparotomy due to bleeding E | 7 | (0.3) | 1 | (0.1) | 0.53 (0.07–4.33) | 1.000 | |
| Hysterectomy E | 2 | (0.1) | 0 | (0.0) | – | – | |
| Postpartum transfer to intensive care unit (ICU) | 25 | (1.0) | 3 | (0.4) | 0.45 (0.13–1.48) | 0.174 | |
| Severe preeclampsia postpartum with ICU stay | 15 | (0.6) | 1 | (0.2) | 0.219 | ||
| Postpartum transfer to ICU (except severe preeclampsia) E | 10 | (0.4) | 2 | (0.3) | 0.74 (0.16–3.39) | 1.000 | |
| Impaired wound healing | 30 | (1.2) | 11 | (1.6) | 1.37 (0.68–2.75) | 0.370 | |
| Definition of wound healing | Wound infection E | 12 | (0.5) | 1 | (0.1) | ||
| Hematoma with evacuation E | 4 | (0.2) | 2 | (0.3) | |||
| Wound dehiscence with secondary closure E | 2 | (0.1) | 2 | (0.3) | |||
| Abscess E | 1 | (0.0) | 0 | (0.0) | |||
| Others | 11 | (0.4) | 6 | (0.9) | |||
| Sepsis E | 1 | (0.0) | 0 | (0.0) | – | – | |
| General complications during the postpartum hospital stay | 100 | (4.0) | 22 | (3.3) | 0.81 (0.51–1.30) | 0.385 | |
| Definition of general complications | Endometritis/Endomyometritis E | 4 | (0.2) | 0 | (0.0) | ||
| Deep vein thrombosis (DVT) E | 2 | (0.1) | 0 | (0.0) | |||
| Ileus E | 3 | (0.1) | 1 | (0.1) | |||
| Postpartum depression E | 4 | (0.2) | 0 | (0.0) | |||
| Others | 87 | (3.5) | 21 | (3.1) | |||
| Postpartum hospital stay in days | Median (IQR) | 5 (2) | 3 (2) | < 0.001 | |||
| Maternal death E | 0 | (0.0) | 0 | (0.0) | |||
| Composite variable ‘postpartum maternal mortality and severe morbidity’.‡ | 65 | (2.6) | 19 | (2.8) | 1.09 (0.65–1.83) | 0.752 | |
Birth parameters
We analyzed birth parameters across groups (see Table 4 and Table 5 ). A significant difference was found in the use of external cephalic version (ECV) for the VBB group (p < 0.001). Spontaneous labor onset was more common in the VBB group (p < 0.001). The VBB group had a higher rate of CTG abnormalities (p < 0.001) and a lower rate of anesthesia (p < 0.001), since CS always require anesthesia. The emergency CS rate was significantly higher in the VBB group (p < 0.001). In unplanned emergency CS, difficult fetal extraction was mentioned in some cases. The term “difficult fetal extraction” was used when the obstetrician indicated in the report that delivering the baby in a breech position was challenging. This applied either during a cesarean section (CS) or a vaginal breech birth (VBB) when additional maneuvers were required to facilitate the baby’s delivery. Cord entanglement was defined as the presence of the umbilical cord wrapped around the fetus’ neck, body, or extremities.
Table 4 Birth characteristics: Parameters divided between the intended birth mode (CS versus intended VBB).
| Birth characteristics | Intended birth mode | |||||
| Planned CS | Intended VBB | |||||
| n = 2501 | (%) | n = 671 | (%) | Sig. | ||
| Performance of an external cephalic version (ECV) | 822 | (32.9) | 492 | (73.3) | < 0.001 | |
| Spontaneous onset of labor | 364 | (14.6) | 668 | (99.6) | < 0.001 | |
| Anesthesia during birth | < 0.001 | |||||
| None | 0 | (0.0) | 205 | (30.6) | ||
| Regional anesthesia | 2364 | (94.5) | 436 | (65.0) | ||
| Intubation | 137 | (5.5) | 30 | (4.5) | ||
| CTG abnormalities | < 0.001 | |||||
| Suspicious | 34 | (1.4) | 68 | (10.1) | ||
| Pathologic | 21 | (0.8) | 79 | (11.8) | ||
| Pathologic – terminal bradycardia | 6 | (0.2) | 27 | (4.0) | ||
| Relative indication for CS | 0.007 | |||||
| Suspicion for relative disproportion | 44 | (1.8) | 15 | (2.2) | ||
| Unfavorable fetal factors | 38 | (1.5) | 14 | (2.1) | ||
| Footling breech presentation | 11 | (0.4) | 8 | (1.2) | ||
| Cord presentation | 11 | (0.4) | 0 | (0.0) | ||
| Presenting hand | 0 | (0.0) | 2 | (0.3) | ||
| “Absolute” indications for CS | < 0.001 | |||||
| Terminal bradycardia | 0 | (0.0) | 2 | (0.3) | ||
| Cord prolapse | 5 | (0.2) | 8 | (1.2) | ||
| Footling presentation | 3 | (0.1) | 6 | (0.9) | ||
| Placental abruption | 8 | (0.3) | 4 | (0.6) | ||
| Uterine rupture | 13 | (0.5) | 1 | (0.1) | ||
| Amniotic infection syndrome | 3 | (0.1) | 4 | (0.6) | ||
| Others | 0 | (0.0) | 1 | (0.1) | ||
| Emergency CS | 10 | (0.4) | 16 | (2.4) | < 0.001 | |
| Difficult fetal extraction | 52 | (2.1) | 40 | (6.0) | < 0.001 | |
| Umbilical cord entanglement | 103 | (4.1) | 62 | (9.2) | < 0.001 | |
| Abnormal placenta position | Placenta previa | 16 | (0.6) | 0 | (0.0) | |
| Retained placenta | 195 | (7.8) | 61 | (9.1) | 0.277 | |
Table 5 Birth characteristics. Parameters divided between the birth mode CS (planned CS and CS after spontaneous onset of labor) and intended VBB (successful VBB versus secondary CS after intended VBB).
| Birth characteristics | Birth mode | ||||||||
| Planned CS | Secondary CS after spontaneous onset of labor | Secondary CS after an unsuccessful attempted VBB | Successful VBB | ||||||
| n = 1806 | (%) | n = 694 | (%) | n = 147 | (%) | n = 525 | (%) | ||
| Performance of an external cephalic version (ECV) | 571 | (31.6) | 251 | (36.2) | 119 | (81.0) | 373 | (71.1) | |
| Spontaneous onset of labor | 0 | (0.0) | 363 | (52.3) | 144 | (98.0) | 525 | (100.0) | |
| Anesthesia during labor | None | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 206 | (39.2) |
| Regional anesthesia | 1726 | (95.6) | 637 | (91.8) | 117 | (79.6) | 319 | (60.8) | |
| Intubation | 80 | (4.4) | 57 | (8.2) | 30 | (20.4) | 0 | (0.0) | |
| CTG abnormalities | Suspicious | 21 | (1.2) | 13 | (1.9) | 20 | (13.6) | 48 | (9.1) |
| Pathologic | 13 | (0.7) | 8 | (1.2) | 37 | (25.2) | 42 | (8.0) | |
| Pathologic – terminal bradycardia | 2 | (0.1) | 4 | (0.6) | 14 | (9.5) | 13 | (2.5) | |
| Relative indications for CS | Suspicion for relative disproportion | 37 | (2.0) | 7 | (1.0) | 11 | (7.5) | 4 | (0.8) |
| Unfavorable fetal factors | 18 | (1.0) | 20 | (2.9) | 12 | (8.2) | 2 | (0.4) | |
| Footling breech presentation | 1 | (0.1) | 10 | (1.4) | 8 | (5.4) | 0 | (0.0) | |
| Cord presentation | 5 | (0.3) | 6 | (0.9) | 0 | (0.0) | 0 | (0.0) | |
| Presenting Hand | 0 | (0.0) | 0 | (0.0) | 2 | (1.4) | 0 | (0.0) | |
| “Absolute” indications for CS | Terminal bradycardia | 0 | (0.0) | 0 | (0.0) | 1 | (0.7) | 1 | (0.2) |
| Cord prolapse | 0 | (0.0) | 5 | (0.7) | 8 | (5.4) | 0 | (0.0) | |
| Footling presentation | 0 | (0.0) | 2 | (0.3) | 4 | (2.7) | 3 | (0.6) | |
| Placental abruption | 3 | (0.2) | 5 | (0.7) | 1 | (0.7) | 3 | (0.6) | |
| Uterine rupture | 10 | (0.6) | 3 | (0.4) | 1 | (0.7) | 0 | (0.0) | |
| Amniotic infection syndrome | 0 | (0.0) | 3 | (0.4) | 2 | (1.4) | 2 | (0.4) | |
| Others | 0 | (0.0) | 0 | (0.0) | 1 | (0.7) | 0 | (0.0) | |
| Emergency CS | 2 | (0.1) | 8 | (1.2) | 16 | (10.9) | 0 | (0.0) | |
| Difficult fetal development | 36 | (2.0) | 16 | (2.3) | 13 | (8.8) | 27 | (5.1) | |
| Umbilical cord entanglement | 76 | (4.2) | 27 | (3.9) | 17 | (11.6) | 45 | (8.6) | |
| Abnormal placenta position | Placenta previa | 14 | (0.8) | 2 | (0.3) | 0 | (0.0) | 0 | (0.0) |
| Retained placenta | 127 | (7.0) | 68 | (9.8) | 18 | (12.2) | 43 | (8.2) | |
There were no significant differences in spontaneous labor onset between successful (100%) and unsuccessful (98%) VBBs (see Table 5 ).
Fetal characteristics
Over 80% of babies in both groups had frank or complete breech presentations. Amniotic fluid levels were mostly normal in both groups. A significant difference in gestational age (p < 0.01) was observed, with planned CS often performed before 39 weeks, while many VBBs occurred after the due date. There were no significant differences in sex or birth weight. However, more babies in the VBB group had weights below the 10th percentile, and fewer had weights above the 90th percentile (p = 0.002).
In neonatal care, the VBB group had higher rates of bag-mask ventilation and resuscitation (p < 0.001). Oxygen therapy was more common in this group (p = 0.015), but intubation rates did not differ significantly (p = 0.184).
Neonatal morbidity was higher in the VBB group for infections (p < 0.001), transient tachypnea (p = 0.002), and hypoxic-ischemic encephalopathy (HIE) (p = 0.008). No significant differences were found for hypoglycemia (p = 0.075), hypothermia (p = 0.672), or hyperbilirubinemia (p = 0.016).
APGAR scores at 1, 5, and 10 minutes were lower in the VBB group (p < 0.001). The 5-minute APGAR score (p < 0.001) and umbilical cord pH also differed significantly, with a median of 7.32 in the CS group and 7.26 in the VBB group. The VBB group showed higher rates of umbilical cord pH < 7.1 and < 7.0, as well as a base excess ≥ 15 mmol/L. Fetal birth trauma was more common in the VBB group (p < 0.001). Fetal birth trauma included fracture of bones, e.g. clavicle, humerus, trochanter, skull, lesion of plexus brachialis, facial nerve palsy, injury of M. sternocleidomastoideus, incision injury during CS, hematoma, or injury to the externa genitalia.
Transfers to the NICU after vaginal birth were also more frequent in the VBB group (p < 0.001). One neonatal death occurred in the VBB group, and none in the CS group. The composite variable for fetal mortality and severe morbidity was significantly higher in the VBB group (p < 0.001) (see Table 5 ).
Four cases of HIE occurred in the intended VBB group, all associated with CTG abnormalities. In each case, experienced obstetricians with more than 10 VBB were present. In one case, an emergency CS was performed during the first stage of labor due to non-reassuring fetal heart rate patterns. In the other three cases, vaginal delivery was achieved after onset of CTG abnormalities in the second stage of labor. See Table 6 and Table 7 .
Table 6 Fetal characteristics divided between intended birth mode CS versus VBB.
| Fetal characteristics | Intended birth mode | |||||||
| Planned CS | Intended VBB | |||||||
| n = 2501 | (%) | n = 671 | (%) | Sig. | ||||
|
D
Included criterion for the composite variable ‘fetal
mortality and severe morbidity’.
‡ Cases with severe malformation or syndrome were excluded. | ||||||||
| Variant of breech presentation | ||||||||
| Frank breech position | 1924 | (76.9) | 482 | (71.8) | ||||
| Complete breech position | 301 | (12.0) | 137 | (20.4) | ||||
| Footling breech position | 53 | (2.1) | 41 | (6.1) | ||||
| Knee breech position | 1 | (0.0) | 1 | (0.1) | ||||
| Breech not specifically defined | 222 | (8.9) | 10 | (1.5) | ||||
| Amount of amniotic fluid | 0.290 | |||||||
| Oligohydramnios | 159 | (6.4) | 41 | (6.1) | ||||
| Polyhydramnios | 33 | (1.3) | 4 | (0.6) | ||||
| Normal | 2309 | (92.3) | 626 | (93.3) | ||||
| Abnormal fetal intrauterine condition | Placenta insufficiency/abnormal Doppler | 63 | (2.5) | 9 | (1.3) | 0.069 | ||
| Gestational week | < 0.001 | |||||||
| 36+0–36+6 | 205 | (8.2) | 42 | (6.3) | ||||
| 37+0–37+6 | 444 | (17.8) | 56 | (8.3) | ||||
| 38+0–38+6 | 1070 | (42.8) | 129 | (19.2) | ||||
| 39+0–39+6 | 659 | (26.3) | 197 | (29.4) | ||||
| 40+0–40+6 | 106 | (4.2) | 165 | (24.6) | ||||
| ≥ 41+0 | 17 | (0.7) | 82 | (12.2) | ||||
| Birth weight | 0.102 | |||||||
| < 2500 g | 173 | (6.9) | 28 | (4.2) | ||||
| 2500 g–2999 g | 720 | (28.8) | 194 | (28.9) | ||||
| 3000 g–3799 g | 1445 | (57.8) | 401 | (59.8) | ||||
| 3800 g–3999 g | 98 | (3.9) | 32 | (4.8) | ||||
| ≥ 4000 g | 65 | (2.6) | 16 | (2.4) | ||||
| Birth weight percentiles | 0.002 | |||||||
| < 10th Percentile | 339 | (13.6) | 116 | (17.3) | ||||
| 10th–90th Percentile | 2073 | (82.9) | 545 | (81.2) | ||||
| > 90th Percentile | 89 | (3.6) | 10 | (1.5) | ||||
| Malformation of the newborn | 448 | (17.9) | 138 | (20.6) | 0.116 | |||
| Severe malformation or syndrome of the newborn | 38 | (1.5) | 2 | (0.3) | 0.012 | |||
| Neonatal care in the delivery room | Bag-mask ventilation | 415 | (16.6) | 173 | (25.8) | < 0.001 | ||
| Oxygen therapy | 447 | (17.9) | 148 | (22.1) | 0.015 | |||
| Intubation | 17 | (0.7) | 8 | (1.2) | 0.184 | |||
| Reanimation | 0 | (0.0) | 8 | (1.2) | < 0.001 | |||
| Neonatal morbidity | Transient tachypnea of the newborn (TTN) | 318 | (12.7) | 114 | (17.0) | 0.002 | ||
| Hypoxic-ischemic encephalopathy (HIE) | 1 | (0.0) | 4 | (0.6) | 0.008 | |||
| Neonatal infection | 151 | (6.0) | 84 | (12.5) | < 0.001 | |||
| Hypoglycemia | 333 | (13.3) | 72 | (10.7) | 0.075 | |||
| Hypothermia | 260 | (10.4) | 66 | (9.8) | 0.672 | |||
| Hyperbilirubinemia | 181 | (7.2) | 31 | (4.6) | 0.016 | |||
| Feeding issues in the newborn | 486 | (19.4) | 118 | (17.6) | 0.279 | |||
| APGAR score after 1 minute | Median (IQR) | 9 (1) | 8 (2) | < 0.001 | ||||
| After 5 minutes | Median (IQR) | 10 (0) | 10 (1) | < 0.001 | ||||
| After 10 minutes | Median (IQR) | 10 (0) | 10 (0) | < 0.001 | ||||
| 5-minutes APGAR score | < 7 | 13 | (0.5) | 16 | (2.4) | < 0.001 | ||
| < 4 D | 0 | (0.0) | 3 | (0.4) | 0.01 | |||
| Umbilical cord pH | Median (IQR) | 7.32 (0.07) | 7.26 (0.13) | < 0.001 | ||||
| < 7.1 | 13 | (0.5) | 47 | (7.0) | < 0.001 | |||
| < 7.0 | 2 | (0.1) | 11 | (1.6) | < 0.001 | |||
| unknown | 13 | (0.5) | 1 | (0.1) | ||||
| Base excess | ≥ 15 mmol/L D | 8 | (0.3) | 19 | (2.8) | < 0.001 | ||
| unknown | 33 | (1.3) | 3 | (0.5) | ||||
| Fetal birth trauma | 26 | (1.0) | 37 | (5.5) | < 0.001 | |||
| Type of birth trauma | Fracture of the clavicle | 1 | (0.0) | 4 | (0.6) | |||
| Fracture of the humerus | 0 | (0.0) | 1 | (0.1) | ||||
| Fracture of the trochanter | 0 | (0.0) | 1 | (0.1) | ||||
| Skull fracture D | 0 | (0.0) | 1 | (0.1) | ||||
| Lesion of Plexus brachialis D | 2 | (0.1) | 9 | (1.3) | ||||
| Facial nerve palsy D | 4 | (0.2) | 0 | (0.0) | ||||
| Injury of M. sternocleidomastoideus | 0 | (0.0) | 1 | (0.1) | ||||
| Incision injury during CS | 16 | (0.6) | 2 | (0.3) | ||||
| Hematoma | 0 | (0.0) | 6 | (0.9) | ||||
| Injury to the external genitalia | 0 | (0.0) | 10 | (1.5) | ||||
| Birth trauma without detailed information | 3 | (0.1) | 3 | (0.4) | ||||
| Transfer to NICU | 119 | (4.8) | 54 | (8.0) | < 0.001 | |||
| Length of stay in the NICU | ≤ 4 days | 60 | (2.4) | 42 | (6.3) | |||
| > 4 days | 50 | (2.0) | 12 | (1.8) | ||||
| unknown | 9 | (0.4) | 0 | (0.0) | ||||
| Invasive ventilation of the newborn (malformations excluded) | 7 | (0.3) | 7 | (1.0) | 0.017 | |||
| Intubation > 24 h (malformations excluded) | 6 | (0.2) | 6 | (0.9) | 0.027 | |||
| Non-invasive ventilation of the newborn (malformations excluded) | 16 | (0.7) | 17 | (2.5) | < 0.001 | |||
| Other interventions in the NICU (malformations excluded) | Thoracic drainage | 2 | (0.1) | 2 | (0.3) | |||
| Hypothermia treatment | 0 | (0.0) | 4 | (0.6) | ||||
| Blood transfusion/Exchange transfusion | 2 | (0.1) | 0 | (0.0) | ||||
| Unknown | 9 | (0.4) | 0 | (0.0) | ||||
| Reason for transfer to the NICU | transient tachypnea of the newborn (TTN) | 31 | (1.2) | 23 | (3.4) | |||
| transient tachypnea of the newborn (TTN) + (suspicion of) neonatal infection |
14 | (0.6) | 7 | (1.0) | ||||
| (suspicion of) neonatal infection | 5 | (0.2) | 1 | (0.1) | ||||
| Hypoxia/Acidosis | 0 | (0.0) | 14 | (2.1) | ||||
| Birth trauma | 0 | (0.0) | 3 | (0.4) | ||||
| Hypoglycemia | 6 | (0.2) | 2 | (0.3) | ||||
| Hypothermia | 0 | (0.0) | 0 | (0.0) | ||||
| Prematurity/low birth weight | 5 | (0.2) | 1 | (0.1) | ||||
| Hyperbilirubinemia | 1 | (0.0) | 0 | (0.0) | ||||
| Hearth rhythm disorder | 4 | (0.2) | 0 | (0.0) | ||||
| Hematologic cause | 5 | (0.2) | 0 | (0.0) | ||||
| Withdrawal symptoms due to maternal drug or medication use | 3 | (0.1) | 0 | (0.0) | ||||
| Cramps | 1 | (0.0) | 0 | (0.0) | ||||
| Maternal risk factors | 1 | (0.0) | 0 | (0.0) | ||||
| Others | 5 | (0.2) | 1 | (0.1) | ||||
| Fetal malformations | 38 | (1.5) | 2 | (0.3) | ||||
| Transfer to NICU due to severe malformation or syndrome | 38 | (1.5) | 2 | (0.3) | 0.012 | |||
| Prenatal death | 0 | (0.0) | 0 | (0.0) | – | |||
| Postnatal death | 0 | (0.0) | 1 | (0.1) | – | |||
| composite variable ‘fetal mortality and severe morbidity’‡ | 40 | (1.6) | 35 | (5.2) | < 0.001 | |||
Table 7 Fetal characteristics divided between the birth mode CS (planned CS and CS after spontaneous onset of labor) and intended VBB (successful VBB versus secondary CS after intended VBB).
| Birth mode | |||||||||
| Planned CS | Secondary CS after spontaneous onset of labor | Secondary CS after an unsuccessful attempted VBB | Successful VBB | ||||||
| n = 1806 | (%) | n = 694 | (%) | n = 147 | (%) | n = 525 | (%) | ||
|
D
Included criterion for the composite ‘variable fetal
mortality and severe morbidity’.
‡ Cases with severe malformation or syndrome were excluded. | |||||||||
| Variant of breech presentation | Frank breech position | 1406 | (77.9) | 518 | (74.6) | 95 | (64.6) | 387 | (73.7) |
| Complete breech position | 197 | (10.9) | 103 | (14.9) | 38 | (25.9) | 100 | (19.0) | |
| Footling breech position | 35 | (1.9) | 18 | (2.6) | 9 | (6.1) | 32 | (6.1) | |
| Knee breech position | 0 | (0.0) | 1 | (0.1) | 1 | (0.7) | 0 | (0.0) | |
| Breech not specifically defined | 168 | (9.3) | 54 | (7.8) | 4 | (2.7) | 6 | (1.1) | |
| Amount of amniotic fluid | |||||||||
| Oligohydramnios | 134 | (7.4) | 25 | (3.6) | 3 | (2.0) | 38 | (7.2) | |
| Polyhydramnios | 27 | (1.5) | 6 | (0.9) | 1 | (0.7) | 3 | (0.6) | |
| Normal | 1646 | (91.0) | 662 | (95.7) | 143 | (97.3) | 484 | (92.2) | |
| Abnormal fetal intrauterine condition | Placenta insufficiency/abnormal Doppler | 55 | (3.1) | 8 | (1.2) | 2 | (1.4) | 7 | (1.3) |
| Gestational week | 36+0–36+6 | 75 | (4.1) | 130 | (18.8) | 9 | (6.1) | 33 | (6.3) |
| 37+0–37+6 | 254 | (14.0) | 190 | (27.5) | 8 | (5.4) | 48 | (9.1) | |
| 38+0–38+6 | 853 | (47.2) | 217 | (31.3) | 23 | (15.6) | 106 | (20.2) | |
| 39+0–39+6 | 557 | (30.8) | 101 | (14.6) | 38 | (25.9) | 160 | (30.5) | |
| 40+0–40+6 | 62 | (3.4) | 44 | (6.4) | 38 | (25.9) | 127 | (24.2) | |
| ≥ 41+0 | 5 | (0.3) | 12 | (1.7) | 31 | (21.1) | 51 | (9.7) | |
| Birth weight | < 2500 g | 124 | (6.9) | 49 | (7.1) | 4 | (2.7) | 24 | (4.6) |
| 2500 g–2999 g | 452 | (25.0) | 268 | (38.7) | 32 | (21.8) | 162 | (30.9) | |
| 3000 g–3799 g | 1095 | (60.6) | 349 | (50.3) | 93 | (63.3) | 309 | (58.9) | |
| 3800 g–3999 g | 79 | (4.4) | 19 | (2.7) | 12 | (8.2) | 20 | (3.8) | |
| ≥ 4000 g | 56 | (3.1) | 9 | (1.3) | 6 | (4.1) | 10 | (1.9) | |
| Birth weight percentiles | < 10th Percentile | 238 | (13.2) | 101 | (14.6) | 21 | (14.3) | 95 | (18.1) |
| 10th– 90th Percentile | 1496 | (82.8) | 576 | (83.0) | 122 | (83.0) | 424 | (80.8) | |
| > 90th Percentile | 72 | (4.0) | 17 | (2.5) | 4 | (2.7) | 6 | (1.1) | |
| Malformation of the newborn | 306 | (16.9) | 142 | (20.5) | 46 | (31.3) | 92 | (17.5) | |
| Severe malformation or syndrome | 29 | (1.6) | 9 | (1.3) | 0 | (0.0) | 2 | (0.4) | |
| Neonatal care in the delivery room | Bag-mask ventilation | 305 | (16.9) | 109 | (15.7) | 46 | (31.3) | 128 | (24.4) |
| Oxygen therapy | 325 | (18.0) | 122 | (17.6) | 44 | (29.9) | 104 | (19.8) | |
| Intubation | 12 | (0.7) | 5 | (0.7) | 2 | (1.4) | 6 | (1.1) | |
| Reanimation | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 8 | (1.5) | |
| Neonatal morbidity | Transient tachypnea of the newborn (TTN) | 222 | (12.3) | 96 | (13.8) | 27 | (18.4) | 87 | (16.6) |
| Hypoxic-ischemic encephalopathy (HIE) | 1 | (0.1) | 0 | (0.0) | 1 | (0.7) | 3 | (0.6) | |
| Neonatal infection | 94 | (5.2) | 56 | (8.1) | 22 | (15.0) | 63 | (12.0) | |
| Hypoglycemia | 242 | (13.4) | 91 | (13.1) | 20 | (13.6) | 52 | (9.9) | |
| Hypothermia | 165 | (9.1) | 95 | (13.7) | 14 | (9.5) | 52 | (9.9) | |
| Hyperbilirubinemia | 129 | (7.1) | 52 | (7.5) | 2 | (1.4) | 29 | (5.5) | |
| Feeding issues in the newborn | 326 | (18.1) | 160 | (23.1) | 43 | (29.3) | 75 | (14.3) | |
| APGAR score after 1 minute | Median (IQR) | 9 (1) | 9 (1) | 8 (3) | 8 (2) | ||||
| After 5 minutes | Median (IQR) | 10 (0) | 10 (0) | 10 (1) | 10 (1) | ||||
| After 10 minutes | Median (IQR) | 10 (0) | 10 (0) | 10 (0) | 10 (0) | ||||
| 5 minutes APGAR score | < 7 | 11 | (0.6) | 2 | (0.3) | 5 | (3.4) | 11 | (2.1) |
| < 4 D | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 3 | (0.6) | |
| Umbilical cord pH | Median (IQR) | 7.32 (0.07) | 7.32 (0.06) | 7.29 (0.09) | 7.25 (0.14) | ||||
| < 7.1 | 12 | (0.7) | 1 | (0.1) | 6 | (4.1) | 41 | (7.8) | |
| < 7.0 | 2 | (0.1) | 0 | (0.0) | 1 | (0.7) | 10 | (1.9) | |
| Unknown | 7 | (0.4) | 6 | (0.9) | 0 | (0.0) | 1 | (0.2) | |
| Base excess | ≥ 15 mmol/L D | 8 | (0.4) | 0 | (0.0) | 2 | (1.4) | 17 | (3.2) |
| Unknown | 21 | (1.2) | 12 | (1.7) | 0 | (0.0) | 3 | (0.6) | |
| Fetal birth trauma | 15 | (0.8) | 11 | (1.6) | 7 | (4.8) | 30 | (5.7) | |
| Type of birth trauma | Fracture of the clavicle | 1 | (0.1) | 0 | (0.0) | 0 | (0.0) | 4 | (0.8) |
| Fracture of the humerus | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 1 | (0.2) | |
| Fracture of the trochanter | 0 | (0.0) | 0 | (0.0) | 1 | (0.7) | 0 | (0.0) | |
| Skull fracture | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 1 | (0.2) | |
| Lesion of Plexus brachialis D | 1 | (0.1) | 1 | (0.1) | 0 | (0.0) | 9 | (1.7) | |
| Facial nerve palsy D | 1 | (0.1) | 3 | (0.4) | 0 | (0.0) | 0 | (0.0) | |
| Injury of M. sternocleidomastoideus | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 1 | (0.2) | |
| Incision injury during CS | 10 | (0.6) | 6 | (0.9) | 2 | (1.4) | 0 | (0.0) | |
| Hematoma | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 6 | (1.1) | |
| Injury to the external genitalia | 0 | (0.0) | 0 | (0.0) | 3 | (2.0) | 7 | (1.3) | |
| Birth trauma without detailed information | 2 | (0.1) | 1 | (0.1) | 1 | (0.7) | 2 | (0.4) | |
| Transfer to NICU | 83 | (4.6) | 36 | (5.2) | 13 | (8.8) | 41 | (7.8) | |
| Length of stay in the NICU | ≤ 4 days | 40 | (2.2) | 20 | (2.9) | 12 | (8.2) | 30 | (5.7) |
| > 4 days | 37 | (2.1) | 13 | (1.9) | 1 | (0.7) | 11 | (2.1) | |
| Stay in the NICU > 4 days (malformations excluded) D | 20 | (1.1) | 5 | (0.7) | 1 | (0.7) | 9 | (1.7) | |
| Invasive ventilation of the newborn (Malformations excluded) | 5 | (0.3) | 2 | (0.3) | 0 | (0.0) | 7 | (1.3) | |
| Intubation > 24 h (Malformations excluded) D | 4 | (0.2) | 2 | (0.3) | 0 | (0.0) | 6 | (1.1) | |
| Non-invasive ventilation of the newborn (Malformations excluded) | 12 | (0.7) | 4 | (0.6) | 6 | (4.1) | 11 | (2.1) | |
| Other interventions in the NICU (Malformations excluded) | Thoracic drainage | 1 | (0.1) | 1 | (0.1) | 0 | (0.0) | 2 | (0.4) |
| Hypothermia treatment | 0 | (0.0) | 0 | (0.0) | 1 | (0.7) | 3 | (0.6) | |
| Blood transfusion/Exchange transfusion | 2 | (0.1) | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | |
| Reason for transfer to the NICU | transient tachypnea of the newborn (TTN) | 21 | (0.6) | 10 | (1.5) | 7 | (4.8) | 16 | (3.0) |
| transient tachypnea of the newborn (TTN) + (suspicion of) neonatal infection | 9 | (0.5) | 5 | (0.7) | 3 | (2.0) | 4 | (0.8) | |
| (Suspicion of) neonatal infection | 2 | (0.1) | 3 | (0.4) | 0 | (0.0) | 1 | (0.2) | |
| Hypoxia/Acidosis | 0 | (0.0) | 0 | (0.0) | 1 | (0.7) | 13 | (2.5) | |
| Birth trauma | 0 | (0.0) | 0 | (0.0) | 1 | (0.7) | 2 | (0.4) | |
| Hypoglycemia | 3 | (0.2) | 3 | (0.4) | 0 | (0.0) | 2 | (0.4) | |
| Hypothermia | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | |
| Prematurity/low birth weight | 4 | (0.2) | 1 | (0.1) | 0 | (0.0) | 1 | (0.2) | |
| Hyperbilirubinemia | 0 | (0.0) | 1 | (0.1) | 0 | (0.0) | 0 | (0.0) | |
| Hearth rhythm disorder | 3 | (0.2) | 1 | (0.1) | 0 | (0.0) | 0 | (0.0) | |
| Hematologic cause | 4 | (0.2) | 1 | (0.1) | 0 | (0.0) | 0 | (0.0) | |
| Withdrawal symptoms due to maternal drug or medication use | 3 | (0.2) | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | |
| Cramps | 0 | (0.0) | 1 | (0.1) | 0 | (0.0) | 0 | (0.0) | |
| Maternal risk factors | 1 | (0.1) | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | |
| Others | 4 | (0.2) | 1 | (0.1) | 1 | (0.7) | 0 | (0.0) | |
| Fetal malformations | 29 | (1.6) | 9 | (1.3) | 0 | (0.0) | 2 | (0.4) | |
| Transfer to the NICU due to fetal malformations or syndromes | 29 | (1.6) | 9 | (1.3) | 0 | (0.0) | 2 | (0.4) | |
| Prenatal death D | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | |
| Postnatal death D | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 1 | (0.2) | |
| Composite variable ‘fetal mortality and severe morbidity’‡ | 30 | (1.7) | 10 | (1.5) | 3 | (2.0) | 32 | (6.1) | |
The cases are detailed below.
Case #1: A primiparous woman at 41+5 weeks GA presented with spontaneous labor onset and received epidural anesthesia. She had a prolonged second stage of labor with pathological CTG. The baby was delivered following Bickenbach and Veit-Smellie maneuvers. The umbilical cord pH was 7.16, BE was −10, and APGAR scores were 1, 6, and 7 at 1, 5, and 10 minutes, respectively. Birth weight was 3685 g (42nd percentile). The neonate was transferred to the NICU, where HIE was diagnosed, and hypothermia treatment was initiated. The baby was discharged after 12 days. Long-term follow-up, with the last examination at 2 years and 10 months of age, showed normal development.
Case #2: A 40+6-week GA, Gravida 2, Para 1 woman presented with spontaneous labor onset and received an epidural. During the second stage of labor, CTG showed terminal bradycardia. The neonate was delivered with difficult fetal extraction, including arm and head delivery. The umbilical cord pH was 6.92, BE was −16, and APGAR scores were 2, 3, and 3. Birth weight was 3000 g (10th percentile). Despite resuscitation and hypothermia treatment, the neonate developed severe bleeding, disseminated intravascular coagulation (DIC), seizures, and a burst-suppression pattern on EEG. Given the poor prognosis and ongoing severe bleeding, treatment was withdrawn, and the baby subsequently died.
Case #3: A nulliparous woman at 40+6 weeks GA presented with premature rupture of membranes (PROM) and developed endogenous contractions. She received epidural analgesia and oxytocin for contraction augmentation. The baby was delivered with maneuvers to facilitate arm (classic arm development) and head (Veit-Smellie) delivery. The umbilical cord pH was 7.22, BE was −8, and APGAR scores were 2, 3, and 7. Birth weight was 3000 g (10th percentile). In addition to HIE, a brachial plexus injury was diagnosed. After four days of hypothermia treatment, the baby recovered, and a subsequent EEG showed normal findings. The neonate was discharged one week after birth. Long-term follow-up data are unavailable.
Case #4: A primigravida at 36+5 weeks GA, who had previously undergone pelvic MRI, presented with PROM and was induced with oxytocin. During the first stage of labor, at 8 cm dilation, CTG showed terminal bradycardia, and an emergency cesarean section was performed after maternal intubation. The umbilical cord pH was 7.04, BE was −8.5, and APGAR scores were 1, 6, and 7. Birth weight was 2745 g (35th percentile). The neonate received hypothermia treatment and non-invasive ventilation. After five days in the NICU and a total hospital stay of 16 days, the baby was discharged. Long-term follow-up is unavailable.
Trends over time
Over the 21-year period analyzed, there has been a noticeable increase in the frequency of VBB, with the most significant rise occurring in the past decade ( Fig. 2 ) when almost 40% of patients were opting for intended VBB.
Fig. 2.
Distribution of intended birth mode for breeches in the time span examined in total ( a ), and distribution of the actual mode of delivery and the changes over time ( b ).
Discussion
We analyzed 21 years of data on breech deliveries in a Tertiary Perinatal Center in Germany to provide recommendations for counseling future patients on the optimal mode of breech delivery. Our cohort revealed a planned CS rate of 78.8% and an intended VBB rate of 21.2%. Among those aiming for VBB, 78% achieved a successful vaginal delivery. Across Europe, the success rate of VBB varies widely, with planned CS rates ranging from 40–90%, depending on national guidelines 9 10 . Notably, our data shows an increase in intended and successful VBB, particularly in the last decade. Compared to national data, where 87.5% of breech presentations result in CS 11 , around 40% of patients in our cohort opted for VBB in the recent ten years.
History of VBB at our center
The introduction of VBB at our center began over 20 years ago in response to a lack of hospitals offering this delivery option. Previously, breech deliveries often took place in unsafe settings without adequately trained obstetricians or neonatologists, resulting in adverse neonatal outcomes and frequent NICU admissions. Some patients seeking VBB even resorted to home births due to the unavailability of hospital-based care with trained staff. This situation highlighted the need for a safe hospital setting for VBB, with trained obstetricians and neonatologists available around the clock, laying the foundation for the VBB program at LMU Klinikum.
Our data show that, over the observed 21-year period, 37 obstetricians managed VBB. Notably, more than 80% of successful VBB were performed by just ten experts, each with experience delivering ten or more VBB. According to a Delphi consensus, competency in VBB requires an initial 10–13 breech deliveries, with 3–6 per year to maintain proficiency 12 . The continuous availability of skilled obstetricians greatly enhances patient counseling and confidence in the option of VBB.
A strength of our study is the extended 21-year observation period in a center with two independent delivery units. However, our data does not capture staff turnover or the extent of knowledge transfer to subsequent generations. Structured training, simulation, and education programs are essential to preserve and enhance VBB skills 13 . This is particularly critical as VBBs can occur unexpectedly, such as in multiparous women or in twin deliveries where the second twin presents in breech 14 15 .
As emphasized by the RCOG top-green guideline, “selection of appropriate pregnancies and skilled intrapartum care may allow planned vaginal breech birth to be nearly as safe as planned vaginal cephalic birth.” 16 . Our data reveals a high rate of successful VBB among multiparous women, especially those with a history of exclusively vaginal births. Consistent with other studies, VBB success is higher among multiparous women, especially those with prior vaginal deliveries and lower BMI 3 17 . However, even in multiparous women, a trained team must be available to ensure safe VBB. Overall, our study population demonstrates a broad spectrum of inclusion criteria with the counseling obstetrician playing a key role in decision-making. FGR and head-to-abdomen circumference divergences were defined as exclusion criteria as growth-restricted fetuses are known for a higher risk of perinatal morbidity and mortality. Weight estimation in FGR is challenging 18 , which may explain the higher number of FGR cases with birth weight below 10th percentile in the group of VBB.
At the start of our VBB program in 2001, there was no strict protocol for the management of breech deliveries, and individual obstetricians applied their own strategies. The use of MRI pelvimetry was also debated, as the benefit of MR-pelvimetry in predicting of successful VBB is not clear until nowadays 19 20 21 . Over time, delivery protocols evolved in line with emerging international literature, such as recommendation for the upright position during breech birth 22 . Standardization of practices and teaching protocols are highly recommended and essential to ensure consistency and to further develop our center of excellence for breech deliveries 7 23 .
Maternal autonomy in choosing the mode of breech delivery is crucial. Studies underscore the importance of informed choice when deciding between CS and VBB 24 25 26 . The increase in planned VBBs in our cohort reflects this trend, as does the higher rate of ECV among the VBB group. While ECV was offered equally to all patients, the higher rate in those seeking VBB likely reflects the desire for a vaginal birth. ECV, recommended at ≥ 36 weeks of gestation 8 16 27 , reduces the prevalence of breech presentations at term. German guidelines recommend the importance of open discussions regarding the mode of delivery for breech births 8 , promoting informed maternal decisions and the selection of experienced providers for VBB. With our center’s concentration of skilled VBB providers, patients in the Munich metropolitan area increasingly seek our unit for breech deliveries, contributing to the rise in VBBs on our delivery ward.
Limitations
Each birth is unique, and comparisons of outcomes can be challenging, particularly when analyzed retrospectively using statistical methods. The TBT findings, which associated VBB with poorer short-term neonatal outcomes, reinforced the preference for CS in breech cases 28 . However, subsequent critiques of the TBT’s methodology 29 30 31 highlight the need for cautious interpretation, particularly regarding long-term neonatal outcomes, which our study did not address as well. While our data show better short-term outcomes for CS in terms of APGAR scores, umbilical cord pH, and NICU transfers, they are limited to immediate postpartum measures and do not evaluate long-term effects. Long-term effects are reported to be independent from delivery mode regarding children at the age of four years 32 .
Recent meta-analyses report higher perinatal mortality and morbidity risks with VBB but also note increased maternal morbidity associated with CS 33 . In our cohort, VBB was associated with significantly lower maternal blood loss and shorter hospital stays. However, long-term maternal outcomes, such as rates of scar pregnancies, abnormal invasive placenta, uterine rupture in subsequent births, urinary incontinence, and pelvic organ prolapse, remain unexplored and must be considered in further studies 34 35 . A Finnish study even showed that a CS for breech presentation in the first pregnancy is associated with adverse neonatal and maternal outcomes in the subsequent delivery 36 .
Neonatal adverse outcomes in the VBB cohort were higher and warrant further discussion. HIE, while rare and occurring in 1.5 to 2.5 per 1000 live births, remains a recognized complication in term infants. Beyond VBB, risk factors for HIE include cord prolapse, shoulder dystocia, uterine rupture, placental abruption, and placenta previa 37 . Despite widespread use of CTG and a significant increase in CS for non-reassuring CTG patterns, the rate of cerebral palsy has not decreased in developed countries in recent decades 38 . An analysis of the four HIE cases in the VBB cohort revealed non-reassuring fetal heart rate patterns. Depending on the stage of labor, the leading obstetrician faced the difficult decision of whether to proceed with CS or continue with vaginal delivery.
In one case, emergency CS was performed as the cervix was not fully dilated, and HIE was diagnosed. Performing a CS is not always avoiding an unfavorable fetal outcome. In the second stage of labor, however, the decision to proceed with vaginal birth becomes more complex, as emergency CS may not always be the quickest option for delivery. Unlike cephalic presentations, where vacuum delivery can expedite the second stage, active extraction in breech deliveries is contraindicated due to the risk of worsening outcomes. A retrospective analysis of one HIE case that resulted in neonatal death prompts critical reflection on the decision to proceed with vaginal delivery, even knowing of the mother’s prior spontaneous vaginal delivery. However, pathological CTG tracings, a difficult fetal extraction – including challenges with arm and head development – led to low APGAR scores and severely reduced umbilical pH measures. A retrospective analysis of this case calls for critical reflection on the decision for vaginal delivery even in multiparous women.
Overall, all HIE cases in our cohort occurred under the leadership of experienced obstetricians, with neonatologists present at birth, which are mandatory conditions at our center. It is crucial that breech births are overseen by an experienced team, and that the decision to proceed with a secondary CS in cases of CTG abnormalities or prolonged labor is made more promptly compared to cephalic presentations. This approach helps minimize the risk of poor fetal outcome.
To improve VBB outcomes, targeted root cause analyses of adverse events are imperative 3 . Tools such as “morbidity and mortality conferences” enable institutions to learn from individual cases and systemic errors 39 . At our center, these tools were used to review all VBB cases, particularly those involving adverse perinatal outcomes, including neonatal death and morbidity. Given the elevated risk of neonatal adverse outcomes in breech births, availability of neonatologists and NICU facilities is crucial. Early intervention is critical for neonates with HIE, as the therapeutic window for hypothermia treatment is limited 40 .
As Hofmeyr et al. noted in their Cochrane review 41 , the reduced neonatal morbidity associated with CS must be weighed against increased maternal risks. Ultimately, prioritizing each patient’s informed choice, grounded in a thorough understanding of the risks and benefits of each mode of delivery, is essential 42 .
Conclusion
Our study highlights the value of historical data in shaping a future where women can make informed choices about their mode of delivery in cases of breech presentation.
By analyzing over 20 years of data, we observed a shift from a predominantly cesarean-focused approach to one that includes VBB as a viable option in hospital settings. This shift underscores the need for open discussion about the best delivery mode and skilled providers among obstetricians and neonatologists to offer VBB. Among women attempting VBB, success rates at our center were high, with favorable maternal and neonatal outcomes when timely cesarean decisions were made in response to clinical indicators. Ensuring that women have the option of an informed choice in breech delivery depends on ongoing efforts to maintain and transfer the specialized skills required for safe VBB practice.
Acknowledgement
The authors would like to express their gratitude to all obstetricians and midwives at LMU Klinikum who have managed breech deliveries with great personal commitment and dedication to patient care.
Footnotes
Conflict of Interest The authors declare that they have no conflict of interest.
Contributorsʼ Statement Conceptualization: JB, TS. Data curation: JO. Formal analysis: JO, JB. Methodology: JB. Project administration: JB. Resources: JB, JO, TS. Supervision: SM. Validation: TK, LH. Visualization: JO, JB. Writing – original draft: JB, TS. Writing – review & editing: JO, LH, TK, SM.
References
- 1.Hickok DE, Gordon DC, Milberg JA et al. The frequency of breech presentation by gestational age at birth: a large population-based study. Am J Obstet Gynecol. 1992;166:851–852. doi: 10.1016/0002-9378(92)91347-d. [DOI] [PubMed] [Google Scholar]
- 2.Morris S, Geraghty S, Sundin D. Breech presentation management: A critical review of leading clinical practice guidelines. Women Birth. 2022;35:e233–e242. doi: 10.1016/j.wombi.2021.06.011. [DOI] [PubMed] [Google Scholar]
- 3.Nothelfer A, Friedl TWP, Dayan D et al. Trial and error – Outcome of breech presentation depending on birth mode and root cause analysis of severe adverse events. Eur J Obstet Gynecol Reprod Biol. 2024;299:309–316. doi: 10.1016/j.ejogrb.2024.06.034. [DOI] [PubMed] [Google Scholar]
- 4.Irion O, Hirsbrunner Almagbaly P, Morabia A. Planned vaginal delivery versus elective caesarean section: a study of 705 singleton term breech presentations. Br J Obstet Gynaecol. 1998;105:710–717. doi: 10.1111/j.1471-0528.1998.tb10200.x. [DOI] [PubMed] [Google Scholar]
- 5.Goffinet F, Carayol M, Foidart JM et al. Is planned vaginal delivery for breech presentation at term still an option? Results of an observational prospective survey in France and Belgium. Am J Obstet Gynecol. 2006;194:1002–1011. doi: 10.1016/j.ajog.2005.10.817. [DOI] [PubMed] [Google Scholar]
- 6.Vincent H, Walker S, Hodder A et al. Barriers and facilitators for implementation of OptiBreech collaborative care: A qualitative study as part of an implementation process evaluation. Women Birth. 2024;37:101656. doi: 10.1016/j.wombi.2024.101656. [DOI] [PubMed] [Google Scholar]
- 7.Jennewein L, Brüggmann D, Fischer K et al. Learning Breech Birth in an Upright Position Is Influenced by Preexisting Experience-A FRABAT Prospective Cohort Study. J Clin Med. 2021;10:2117. doi: 10.3390/jcm10102117. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Louwen F, Wagner U, Abou-Dakn M et al. Caesarean Section. Guideline of the DGGG, OEGGG and SGGG (S3-Level, AWMF Registry No. 015/084, June 2020) Geburtshilfe Frauenheilkd. 2021;81:896–921. doi: 10.1055/a-1529-6141. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Toivonen E, Palomäki O, Huhtala H et al. Selective vaginal breech delivery at term – still an option. Acta Obstet Gynecol Scand. 2012;91:1177–1183. doi: 10.1111/j.1600-0412.2012.01488.x. [DOI] [PubMed] [Google Scholar]
- 10.Fuxe V, Brismar Wendel S, Bohm-Starke N et al. Delivery mode and severe maternal and neonatal morbidity among singleton term breech births: A population-based cohort study. Eur J Obstet Gynecol Reprod Biol. 2022;272:166–172. doi: 10.1016/j.ejogrb.2022.03.014. [DOI] [PubMed] [Google Scholar]
- 11.Institut für Qualitätssicherung und Transparenz im Gesundheitswesen (IQTIG) . Bundesauswertung Perinatalmedizin: Geburtshilfe Erfassungsjahr 2021. 2022. https://iqtig.org/downloads/auswertung/2021/pmgebh/DeQS_PM-GEBH_2021_BUAW_V01_2022-06-30.pdf https://iqtig.org/downloads/auswertung/2021/pmgebh/DeQS_PM-GEBH_2021_BUAW_V01_2022-06-30.pdf
- 12.Walker S, Scamell M, Parker P. Standards for maternity care professionals attending planned upright breech births: A Delphi study. Midwifery. 2016;34:7–14. doi: 10.1016/j.midw.2016.01.007. [DOI] [PubMed] [Google Scholar]
- 13.Dhingra S, Raffi F. Obstetric trainees’ experience in VBD and ECV in the UK. J Obstet Gynaecol. 2010;30:10–12. doi: 10.3109/01443610903315629. [DOI] [PubMed] [Google Scholar]
- 14.Walker S, Breslin E, Scamell M et al. Effectiveness of vaginal breech birth training strategies: An integrative review of the literature. Birth. 2017;44:101–109. doi: 10.1111/birt.12280. [DOI] [PubMed] [Google Scholar]
- 15.Mattiolo S, Spillane E, Walker S. Physiological breech birth training: An evaluation of clinical practice changes after a one-day training program. Birth. 2021;48:558–565. doi: 10.1111/birt.12562. [DOI] [PubMed] [Google Scholar]
- 16.[Anonym] . Management of Breech Presentation: Green-top Guideline No. 20b. BJOG. 2017;124:e151–e177. doi: 10.1111/1471-0528.14465. [DOI] [PubMed] [Google Scholar]
- 17.Kielland-Kaisen U, Paul B, Jennewein L et al. Maternal and neonatal outcome after vaginal breech delivery of nulliparous versus multiparous women of singletons at term-A prospective evaluation of the Frankfurt breech at term cohort (FRABAT) Eur J Obstet Gynecol Reprod Biol. 2020;252:583–587. doi: 10.1016/j.ejogrb.2020.04.029. [DOI] [PubMed] [Google Scholar]
- 18.Miranda J, Rodriguez-Lopez M, Triunfo S et al. Prediction of fetal growth restriction using estimated fetal weight vs a combined screening model in the third trimester. Ultrasound Obstet Gynecol. 2017;50:603–611. doi: 10.1002/uog.17393. [DOI] [PubMed] [Google Scholar]
- 19.Klemt AS, Schulze S, Brüggmann D et al. MRI-based pelvimetric measurements as predictors for a successful vaginal breech delivery in the Frankfurt Breech at term cohort (FRABAT) Eur J Obstet Gynecol Reprod Biol. 2019;232:10–17. doi: 10.1016/j.ejogrb.2018.09.033. [DOI] [PubMed] [Google Scholar]
- 20.Franz M, von Bismarck A, Delius M et al. MR pelvimetry: prognosis for successful vaginal delivery in patients with suspected fetopelvic disproportion or breech presentation at term. Arch Gynecol Obstet. 2017;295:351–359. doi: 10.1007/s00404-016-4276-6. [DOI] [PubMed] [Google Scholar]
- 21.Dathan-Stumpf A, Lia M, Meigen C et al. Novel Three-Dimensional Body Scan Anthropometry versus MR-Pelvimetry for Vaginal Breech Delivery Assessment. J Clin Med. 2023;12:6181. doi: 10.3390/jcm12196181. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Louwen F, Daviss BA, Johnson KC et al. Does breech delivery in an upright position instead of on the back improve outcomes and avoid cesareans? Int J Gynaecol Obstet. 2017;136:151–161. doi: 10.1002/ijgo.12033. [DOI] [PubMed] [Google Scholar]
- 23.Casteels M, Podevyn K, Vanoverschelde H et al. Implementation of a breech program in a Belgian obstetric team. Int J Gynaecol Obstet. 2022;158:432–438. doi: 10.1002/ijgo.14003. [DOI] [PubMed] [Google Scholar]
- 24.Schafer R, Dietrich MS, Kennedy HP et al. “I had no choice”: A mixed-methods study on access to care for vaginal breech birth. Birth. 2024;51:413–423. doi: 10.1111/birt.12797. [DOI] [PubMed] [Google Scholar]
- 25.Morris SE, Sundin D, Geraghty S. Women’s experiences of breech birth decision making: An integrated review. Eur J Midwifery. 2022;6:2. doi: 10.18332/ejm/143875. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Wang XR, Cotter H, Fahey M. Women’s Selection of Mode of Birth for their Breech Presentation. J Obstet Gynaecol Can. 2021;43:716–720. doi: 10.1016/j.jogc.2020.09.025. [DOI] [PubMed] [Google Scholar]
- 27.[Anonym] . External Cephalic Version and Reducing the Incidence of Term Breech Presentation: Green-top Guideline No. 20a. BJOG. 2017;124:e178–e192. doi: 10.1111/1471-0528.14466. [DOI] [PubMed] [Google Scholar]
- 28.Hannah ME, Hannah WJ, Hewson SA et al. Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. Lancet. 2000;356:1375–1383. doi: 10.1016/s0140-6736(00)02840-3. [DOI] [PubMed] [Google Scholar]
- 29.Berhan Y, Haileamlak A. The risks of planned vaginal breech delivery versus planned caesarean section for term breech birth: a meta-analysis including observational studies. BJOG. 2016;123:49–57. doi: 10.1111/1471-0528.13524. [DOI] [PubMed] [Google Scholar]
- 30.Bjellmo S, Andersen GL, Martinussen MP et al. Is vaginal breech delivery associated with higher risk for perinatal death and cerebral palsy compared with vaginal cephalic birth? Registry-based cohort study in Norway. BMJ Open. 2017;7:e014979. doi: 10.1136/bmjopen-2016-014979. [DOI] [Google Scholar]
- 31.Korb D, Schmitz T, Alexander S et al. Association between planned mode of delivery and severe maternal morbidity in women with breech presentations: A secondary analysis of the PREMODA prospective general population study. J Gynecol Obstet Hum Reprod. 2020;49:101662. doi: 10.1016/j.jogoh.2019.101662. [DOI] [PubMed] [Google Scholar]
- 32.Macharey G, Väisänen-Tommiska M, Gissler M et al. Neurodevelopmental outcome at the age of 4 years according to the planned mode of delivery in term breech presentation: a nationwide, population-based record linkage study. J Perinat Med. 2018;46:333–339. doi: 10.1515/jpm-2017-0127. [DOI] [PubMed] [Google Scholar]
- 33.Fernández-Carrasco FJ, Cristóbal-Cañadas D, Gómez-Salgado J et al. Maternal and fetal risks of planned vaginal breech delivery vs planned caesarean section for term breech birth: A systematic review and meta-analysis. J Glob Health. 2022;12:4055. doi: 10.7189/jogh.12.04055. [DOI] [Google Scholar]
- 34.Chaillet N, Mâsse B, Grobman WA et al. Perinatal morbidity among women with a previous caesarean delivery (PRISMA trial): a cluster-randomised trial. Lancet. 2024;403:44–54. doi: 10.1016/S0140-6736(23)01855-X. [DOI] [PubMed] [Google Scholar]
- 35.Keag OE, Norman JE, Stock SJ. Long-term risks and benefits associated with cesarean delivery for mother, baby, and subsequent pregnancies: Systematic review and meta-analysis. PLoS Med. 2018;15:e1002494. doi: 10.1371/journal.pmed.1002494. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36.Macharey G, Toijonen A, Hinnenberg P et al. Term cesarean breech delivery in the first pregnancy is associated with an increased risk for maternal and neonatal morbidity in the subsequent delivery: a national cohort study. Arch Gynecol Obstet. 2020;302:85–91. doi: 10.1007/s00404-020-05575-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Allen KA, Brandon DH. Hypoxic Ischemic Encephalopathy: Pathophysiology and Experimental Treatments. Newborn Infant Nurs Rev. 2011;11:125–133. doi: 10.1053/j.nainr.2011.07.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38.Clark SL, Hankins GD. Temporal and demographic trends in cerebral palsy--fact and fiction. Am J Obstet Gynecol. 2003;188:628–633. doi: 10.1067/mob.2003.204. [DOI] [PubMed] [Google Scholar]
- 39.Bevis KS, Straughn JM, jr., Kendrick JE et al. Morbidity and mortality conference in obstetrics and gynecology: a tool for addressing the 6 core competencies. J Grad Med Educ. 2011;3:100–103. doi: 10.4300/JGME-D-10-00093.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 40.Graham EM, Ruis KA, Hartman AL et al. A systematic review of the role of intrapartum hypoxia-ischemia in the causation of neonatal encephalopathy. Am J Obstet Gynecol. 2008;199:587–595. doi: 10.1016/j.ajog.2008.06.094. [DOI] [PubMed] [Google Scholar]
- 41.Hofmeyr GJ, Hannah M, Lawrie TA. Planned caesarean section for term breech delivery. Cochrane Database Syst Rev. 2015;(07):CD000166. doi: 10.1002/14651858.CD000166.pub2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 42.Abdessalami S, Rota H, Pereira GD et al. The influence of counseling on the mode of breech birth: A single-center observational prospective study in The Netherlands. Midwifery. 2017;55:96–102. doi: 10.1016/j.midw.2017.09.012. [DOI] [PubMed] [Google Scholar]