The Evolution of Cephalocentesis in Contemporary Obstetric Practice: From Emergency Intervention to Planned Procedure

Abstract

Introduction

The aim of the study was to analyze the evolution, indications, and outcomes of cephalocentesis over a 38-year period at two tertiary fetal medicine centers.

Methods

A retrospective review of 70 cephalocentesis procedures (1985–2023) was conducted at Mount Sinai Hospital, Toronto, and the National Maternity Hospital, Dublin. Cases were divided into pre-2002 (n = 37) and 2002-onward (n = 33) cohorts in order to evaluate practice evolution.

Results

Mean gestational age at diagnosis was 32.7 ± 5.4 weeks with severe hydrocephalus in 95.7% (67/70) and hydranencephaly in 4.3% (3/70) of cases. Pre-2002, 94.6% (35/37) of procedures were performed intrapartum; 2002 onward, this shifted to 66.7% (22/33) pre-labor planned procedures with 84.8% (28/33) using a transabdominal approach. Concurrent fetal analgesia and potassium chloride (KCl) to achieve fetal asystole was introduced in 2002. Vaginal delivery was achieved in 95.7% (67/70) of cases. Perinatal mortality (excluding KCl cases) was 91.8% (45/49). All four survivors (5.8%) demonstrated neurodevelopmental impairment.

Conclusion

Cephalocentesis has evolved from an intrapartum intervention to a planned procedure with standardized protocols. Our findings support reserving this procedure for cases where there is no expectation of postnatal survival, with the primary purpose of facilitating vaginal delivery when caesarean section could unnecessarily increase maternal morbidity.

Plain Language Summary

This study examines a medical procedure called cephalocentesis, which involves draining fluid from the fetal brain before birth when the fetus has severe hydrocephalus (excess fluid in the brain causing an enlarged head). Researchers looked at 70 cases over 38 years at two major to understand how this procedure has changed over time. When fetuses develop severe hydrocephalus, their heads can become so large that vaginal delivery becomes dangerous for the mother, potentially requiring major surgery (cesarean section). In cases where the fetus is not expected to survive after birth, doctors may perform cephalocentesis to reduce the head size and allow for safer vaginal delivery. The study showed that this procedure has evolved significantly since 2002. Earlier, it was mainly done during labor as an emergency measure. Now, it is typically planned in advance with improved fetal pain management protocols. The procedure successfully allowed vaginal delivery in 96% of cases, avoiding cesarean section for mothers. Most fetuses (92%) did not survive when the procedure was done alone, and the few who did survive had significant developmental disabilities. This confirms that the procedure should only be used when pregnancy termination has already been decided due to severe fetal anomalies. This research helps doctors understand when and how to safely perform this rare but sometimes necessary procedure, focusing on protecting maternal health while providing compassionate care in difficult situations.

Introduction

Cephalocentesis, the aspiration of cerebrospinal fluid from the fetal cranium to reduce its size, emerged in the early 19th century as an intervention of last resort for obstructed labor associated with fetal hydrocephalus [1]. Prior to routine ultrasound, severe hydrocephalus was first diagnosed when mothers presented either post-dates with a high presenting part, in labor with arrest of dilatation or descent, or when difficulty was encountered delivering the aftercoming head during vaginal breech delivery.

Smith’s 1858 “Manual of Obstetrics” documented that Dr. Thomas Keith reported 16 cases of uterine rupture in 70 women attempting to spontaneously deliver hydrocephalic fetuses, illustrating the severe maternal risks that women and their clinicians faced [1]. In that era of limited obstetric alternatives and high maternal mortality rates, physicians prioritized maternal survival through difficult but necessary interventions.

Since that time, the landscape of obstetric care has transformed dramatically with advances in prenatal diagnosis and fetal imaging [2, 3]. Today, severe hydrocephalus can often be detected early in pregnancy, enabling a methodical, evidence-based approach to investigation and management that was previously impossible. Rather than encountering this condition as an obstetric emergency during labor, healthcare providers and families can engage in comprehensive interdisciplinary consultation about management options, associated risks, and potential outcomes [4, 5]. This shift from crisis intervention to informed decision-making represents a fundamental change in how these challenging cases are approached.

However, fetal therapy resources remain heavily concentrated in high-income regions. A global survey found that approximately 77% of fetal intervention centers were located in North America or Europe [6]. In well-resourced healthcare systems with access to experienced fetal medicine teams, detection rates for major structural anomalies can exceed 90% [7–9]. However, in broader population-based practice, rates commonly range from 70 to 85%, depending on operator expertise, scan timing, and imaging quality [10]. In low-resource settings, detection rates may fall below 30%, largely due to limited access to trained personnel, inadequate imaging infrastructure, and late presentation to care [11]. These diagnostic disparities mean that severe fetal anomalies, including hydrocephalus, can still remain unrecognized in pregnancy in some health care settings.

Nevertheless, even in high-resource environments, late diagnoses still occur, and severe fetal hydrocephalus at term presents significant management challenges, particularly in cases with anomalies that are either lethal or associated with severe neurodevelopmental impairment (NDI) [12, 13]. In such situations, when pregnancy termination has been determined to be an appropriate course of action, the method of delivery becomes a critical consideration. The approach must consider maternal safety, potential delivery complications in the index and subsequent pregnancies, risks of perinatal trauma, and the emotional well-being of the parents [14, 15].

Our experience with cephalocentesis has revealed a distinct shift in practice patterns beginning around 2002, with the evolution of protocols to include the administration of fetal sedation and analgesia and the option of using intravascular potassium chloride (KCl) prior to the procedure to achieve fetal systole. This represents an evolution from an urgent intrapartum procedure performed out of necessity to a planned intervention specifically reserved for cases where pregnancy termination has been determined to be appropriate due to severe fetal anomalies which are either lethal or associated with a high risk of very severe NDI [12, 14].

This paper reviews our 38-year experience with cephalocentesis at two tertiary care centers, comparing pre-2002 and 2002-onward approaches. Our primary aim was to examine the changing role of cephalocentesis in contemporary obstetric practice by analyzing procedural characteristics, maternal outcomes (particularly success rates of vaginal delivery), and perinatal outcomes including survival rates and long-term neurodevelopmental follow-up in survivors.

Methods

We conducted a retrospective review of all cases of cephalocentesis performed at Mount Sinai Hospital, Toronto, Canada and the National Maternity Hospital, Dublin, Ireland, from 1985 to 2023. Both institutions are regional tertiary care centers for high-risk pregnancies and fetal anomalies. Cases were identified from institutional records of patients who had undergone cephalocentesis procedures during the study period.

Following approval from the Institutional Research Ethics Boards (REB #: 17-0321-C), data were extracted from maternal and fetal health records, ultrasound reports, procedure records, genetic testing results, labor and delivery documentation, and where available, pediatric follow-up information for any survivors. Severe ventriculomegaly or hydrocephalus was defined as a biparietal diameter and head circumference measuring >95th percentile for gestational age (GA) and a diameter of the atria of one or both lateral ventricles ≥15 mm [13] (Fig. 1).

Fig. 1.

Head circumference (HC) and biparietal diameter (BPD) by GA in severe fetal hydrocephalus. HC (a) and BPD (b) plotted against GA at diagnosis in cases of severe fetal hydrocephalus. Red filled circles represent the four survivors (only one data point available for each survivor). Reference lines show INTERGROWTH-21st centiles (5th, 50th, and 95th centiles).

For analysis purposes, the study population was divided into two cohorts: cases performed before 2002 and those performed from 2002 onward. This division reflects the significant practice shift that occurred with the introduction of standardized protocols for fetal analgesia with the option of using intravascular KCl administration prior to cephalocentesis at the Canadian center, while all cases at the Irish center were performed intrapartum to facilitate delivery of the baby. In 1 Dublin case, cephalocentesis was performed during caesarean section to allow a smaller uterine incision [16].

Two different approaches to cephalocentesis were employed with detailed protocols described in online supplementary Material 1 (for all online suppl. material, see https://doi.org/10.1159/000550077). A transvaginal approach was typically performed intrapartum when the cervix was adequately dilated (≥7 cm). In cephalic presentations, the fetal head was palpated to identify the fontanelles or suture lines as entry points. A spinal needle (most commonly 20 cm 18 G) or larger specialized 9F trocar was introduced through the dilated cervix and directed into the fetal skull by palpation, preferentially through a distended fontanelle to minimize bone fragmentation. In breech presentations, the instrument was introduced in the midline just below the inion of the occiput once the body had been delivered.

Transabdominal cephalocentesis was performed under continuous ultrasound guidance following sterile preparation of the maternal abdomen (Fig. 2). The procedure began with comprehensive ultrasound assessment to identify the optimal entry point, avoiding the placenta and maternal structures while targeting the dilated ventricles. After administration of local anesthesia or under epidural, a long needle or 9F trocar was inserted through the uterine wall into the fetal lateral ventricle. Since 2002 at the Toronto center, the protocol included pre-operative fetal sedation and analgesia in virtually all cases with the option of feticide by fetal intravascular KCl administration, at parental discretion, prior to cranial decompression.

Fig. 2.

Ultrasound image of transabdominal cephalocentesis in a 36⁺⁶ week fetus with hydranencephaly. BPD 15.2 cm, HC 55.6 cm at diagnosis. BPD, biparietal diameter; HC, head circumference.

Statistical analyses were performed using R statistical software (version 4.0.2, R Foundation for Statistical Computing, Vienna, Austria). Descriptive statistics were calculated for the entire cohort and for the pre-2002 and 2002-onward subgroups. Differences between the two time periods were assessed using chi-square or Fisher’s exact test for categorical variables and Student’s t test for continuous variables as appropriate. Statistical significance was defined as p < 0.05.

Results

Maternal and Fetal Characteristics

Between 1985 and 2023, 70 fetuses underwent cephalocentesis for severe hydrocephalus (54 in Toronto, 16 in Dublin). Mean maternal age was 29.1 ± 5.4 years, with 50.7% (n = 35) nulliparous. Mean GA at diagnosis of severe hydrocephalus was 32.7 ± 5.4 weeks, with an average GA at delivery of 36.9 ± 3.6 weeks. The average biparietal diameter and head circumference at diagnosis were 106 ± 18 mm and 369 ± 60 mm respectively (Table 1).

Table 1.

Maternal and fetal characteristics

Characteristics	Total (n = 70)	Pre-2002 (n = 37)	Post-2002 (n = 33)	p value
Maternal characteristics
Age, years, mean±SD	29.2±5.1	29.2±5.6	29.3±4.5	0.93
Nulliparous	35 (50.7)	21 (58.3)	14 (42.4)	0.18
GA at diagnosis, weeks, mean±SD	32.7±5.1	33.1±5.3	32.2±4.9	0.45
GA at delivery, weeks, mean±SD	36.9±3.6	38.7±2.8	34.9±3.3	<0.001*
Fetal characteristics
BPD, mm, mean±SD	106±18	112±15	103±18	0.03*
Head circumference, mm, mean±SD	369±60	359±31	370±63	0.38
Antenatal diagnosis	67 (95.7)	34 (91.9)	33 (100.0)	0.07
Fetal condition
Severe hydrocephalus	67 (95.7)	36 (97.3)	31 (93.9)	0.45
Hydranencephaly	3 (4.3)	1 (2.7)	2 (6.1)	0.45
Isolated hydrocephalus	19 (27.1)	11 (29.7)	8 (24.2)	0.60
Associated anomalies	51 (72.9)	26 (70.3)	25 (75.8)	0.60

Data are presented as n (%) unless otherwise indicated.

*p < 0.05 considered statistically significant.

The presenting diagnosis was severe hydrocephalus in 95.7% (n = 67) and hydranencephaly in 4.3% (n = 3). Hydrocephalus was isolated in 27.1% (n = 19), while additional extracranial and/or intracranial anomalies were present in 72.9% (n = 51). Intracranial anomalies included neural tube defects (n = 16, 23.2%), aqueductal stenosis (n = 15, 21.7%), intracranial hemorrhage (n = 6, 8.7%), encephalocele (n = 3, 4.3%), Dandy-Walker malformation (n = 3, 4.3%), holoprosencephaly (n = 3, 4.3%), Walker-Warburg syndrome (n = 2, 2.9%) and large intracranial tumors (n = 2, 2.9%). Extracranial anomalies were present in 18 cases (26.1%) and included limb/skeletal anomalies (n = 6, 8.7%), cardiac anomalies (n = 4, 5.8%), renal anomalies (n = 4, 5.8%), and cleft lip/palate (n = 2, 2.9%). Genetic testing results were available in 45 fetuses – of these 3 were abnormal: one 69,XXX, one microdeletion (Xp22.31), and one FGFR2 mutation.

When comparing the pre-2002 and 2002-onward cohorts (Table 1), we observed no significant differences in maternal age, parity, or GA at diagnosis. However, the 2002-onward group had a significantly earlier GA at delivery (34.9 ± 3.3 weeks versus 38.7 ± 2.8 weeks, p < 0.001) and a higher rate of identified associated anomalies (76% vs. 63%, p = 0.05), likely reflecting improvements in prenatal diagnostic capabilities.

Procedural Characteristics and Evolution of Practice

The timing and route of cephalocentesis varied significantly between the two time periods (Table 2). In the pre-2002 cohort (n = 37), 35 patients (94.6%) underwent intrapartum procedures near full dilation, including 14 patients (37.8%) requiring cephalocentesis after Løvset’s maneuver to facilitate delivery of the aftercoming head in a breech presentation. Only 1 patient (2.7%) had a pre-labor transabdominal procedure.

Table 2.

Procedural characteristics of cephalocentesis cases

Characteristics	Total (n = 70)	Pre-2002 (n = 37)	Post-2002 (n = 33)	p value
Timing of procedure
Intrapartum	45 (64.3)	35 (94.6)	10 (30.3)	<0.001*
Including during breech delivery after Lovset maneuver	15 (21.4)	14 (37.8)	1 (3.0)	<0.001*
Pre-labor	23 (32.9)	1 (2.7)	22 (66.7)	<0.001*
Prior to caesarean delivery	1 (1.4)	0 (0)	1 (3.0)	0.29
Intraoperative during caesarean delivery	1 (1.4)	1 (2.7)	0 (0)	0.35
Procedural approach
Transabdominal	37 (52.9)	9 (24.3)	28 (84.8)	<0.001*
Transvaginal	32 (45.7)	27 (73.0)	5 (15.2)	<0.001*
Caesarean delivery	1 (1.4)	1 (2.7)	0 (0)	0.35
Procedural details
CSF volume aspirated, mL, mean±SD	484±387	467±366	508±415	0.68
Fetal analgesia and KCl administration	23 (30.0)	0 (0)	23 (63.6)	<0.001*
Labor induction	50 (71.4)	24 (64.9)	26 (78.8)	0.19

Data are presented as n (%) unless otherwise indicated.

CSF, cerebrospinal fluid; KCl, potassium chloride.

*p < 0.05 considered statistically significant.

In contrast, in the 2002-onward cohort (n = 33), there was a shift toward planned interventions, with 28 patients (84.8%) undergoing transabdominal approaches, 22 patients (66.7%) having pre-labor procedures, and only 5 patients (15.2%) having transvaginal procedures. This shift from predominantly intrapartum procedures (94.6% vs. 30.3%, p < 0.001) to predominantly planned pre-labor interventions (2.7% vs. 66.7%, p < 0.001) and from predominantly transvaginal (73.0% vs. 15.2%, p < 0.001) to predominantly transabdominal approaches (24.3% vs. 84.8%, p < 0.001) represents a significant practice evolution.

Various instruments were used, ranging from 22 G needles to 9F trocars, with 18 G 20 cm needles being most commonly used (42% of cases). Mean cerebrospinal fluid volume drained was 484 ± 387 mL (range: 50–1,800 mL). From 2002 onward, 21 fetuses (30% of the total cohort and 63.6% of the post-2002 cohort) underwent combined fetal analgesia with optional KCl administration (Table 2).

Delivery and Perinatal Outcomes

Vaginal delivery was achieved in 95.7% (n = 67) of cases across both time periods (Table 3), including spontaneous vaginal deliveries (n = 29, 41.4%), vaginal breech deliveries (n = 24, 34.3%), and other assisted deliveries. Only three babies (4.3%) required caesarean section (Table 4): one for failure to progress with chorioamnionitis, one at maternal request following feticide, and one for fetal bradycardia with parental request for full resuscitation.

Table 3.

Mode of delivery following cephalocentesis

Mode of delivery	Total (n = 70)	Pre-2002 (n = 37)	Post-2002 (n = 33)	p value
SVD	29 (41.4)	11 (29.7)	18 (54.5)	0.03*
SVD – breech delivery	24 (34.3)	16 (43.2)	8 (24.2)	0.09
Assisted vaginal delivery – forceps	8 (11.4)	7 (18.9)	1 (3.0)	0.03*
Assisted vaginal delivery – vacuum	2 (2.9)	1 (2.7)	1 (3.0)	0.92
VBAC – delivered breech	3 (4.3)	0 (0)	3 (9.1)	0.06
VBAC – delivered cephalic	1 (1.4)	0 (0)	1 (3.0)	0.29
Caesarean delivery	3 (4.3)	2 (5.4)	1 (3.0)	0.63
Total vaginal delivery	67 (95.7)	35 (94.6)	32 (97.0)	0.63

Data are presented as n (%).

SVD, spontaneous vaginal delivery; VBAC, vaginal birth after caesarean.

*p < 0.05.

Table 4.

Cases delivered by caesarean section

Case	Parity	Year	GA at diagnosis of hydrocephalus, weeks	Additional extra- or intracranial anomalies?	Induction of labor method	Cephalocentesis	Fetal heart beat detected after cephalocentesis?	Oxytocin augmentation	Indication for caesarean section	Pediatric outcome	Autopsy
1	G1P0	1990	28	No	Vaginal prostaglandin (PGE2)	Transabdominal, ultrasound-guided at 4 cm dilation, 16 gauge needle, 600 mL CSF drained	No	Yes	CPD (arrest of dilation at 7 cm)	Stillborn male, 3,140 g	Declined
2	G5P4	1994	35+5	No	Vaginal prostaglandin (PGE2)	Intraoperative 16 gauge needle 750 mL CSF drained (parents declined pre-op cephalocentesis)	Yes	No	CPD	Apgars 21 65, male, 2,500 g neonatal death at 2 h 40 min	Declined
3	G1P0	2013	40+0	No	N/A – LSCS for maternal request	Transabdominal with KCl, 18 gauge needle, 400 mL CSF drained	No (KCL)	No	Maternal request	Stillborn, 3,948 g	Obstructive hydrocephalus, nodular heterotopias obstructing aqueduct of Sylvius, encasing leptomeningeal artery, cervicomedullary junction

CSF, cerebrospinal fluid.

Overall perinatal outcomes (Table 5) included 53 stillbirths (75.7%) and 13 neonatal deaths (18.6%, occurring within 3 h–6 days of life). Among stillbirths, 21 (39.6%) followed KCl administration while 32 (60.4%) occurred spontaneously. Excluding cases where KCl was administered, perinatal mortality associated with cephalocentesis alone was 91.8% (45/49 cases).

Table 5.

Perinatal outcomes following cephalocentesis

Outcome	Total (n = 70)	Pre-2002 (n = 37)	Post-2002 (n = 33)	p value
Survivors	4 (5.7)	3 (8.1)	1 (3.0)	0.36
Neonatal death	13 (18.6)	13 (35.1)	0 (0)	<0.001*
Stillbirth (spontaneous)	32 (45.7)	21 (56.8)	11 (33.3)	0.014*
Stillbirth (after KCl administration)	21 (30.0)	0 (0)	21 (63.6)	<0.001*
Total perinatal mortality	66 (94.3)	34 (91.9)	32 (97.0)	0.36
Perinatal mortality (excluding KCl cases)1	45/49 (91.8)	34/37 (91.9)	11/12 (91.7)	0.99

Data are presented as n (%).

KCl, potassium chloride.

*p < 0.05 considered statistically significant.

¹Calculated excluding cases where KCl was administered for fetal demise.

Four fetuses (8.2%) survived to discharge following cephalocentesis without KCl, challenging the perception that the procedure is universally lethal (Table 6). Survival was associated with smaller gauge needles (21-22 G vs. larger gauges, p = 0.03) and isolated hydrocephalus without additional anomalies. This finding has important implications for procedural counseling as families must understand that survival, albeit with significant morbidity, remains possible when KCl is not used. Comparing the two time periods, the 2002-onward cohort had higher stillbirth rates (97.0% vs. 56.8%, p < 0.001) and lower neonatal death rates (0% vs. 35.1%, p < 0.001), primarily reflecting the introduction of KCl administration in the later period.

Table 6.

Pediatric outcome in survivors following cephalocentesis for severe fetal hydrocephalus

Case	GA at diagnosis, weeks	Year	Other extra- or intracranial anomalies?	Method of cephalocentesis	GA at delivery, weeks	Mode of delivery	Neonatal outcome	Postnatal examination	Pediatric follow-up
1	38	1991	No	US-guided, transabdominal at 8 cm dilation, 21 gauge needle 250 mL CSF removed	40+5	Vacuum	Male, 3,620 g	Aqueductal stenosis	1 month – VP shunt inserted
							Apgars 31 65		3 years 4 months – normal cognitive function, mild left hemiplegia
							​		18 years – mild cerebral palsy, attended university
2	40	1994	No	Intrapartum, transvaginal, 22 gauge needle, 300 mL CSF removed	40	SVD	Male, 3,045 g	Neural tube defect at L4	Neonatal – VP shunt
							Apgars 51 85		16 years – wheel-chair bound, attended high school, normal cognitive function
3	36	1994	No	Prior to induction of labor, transvaginal, 22 gauge needle	37	SVD	Male, 3,055 g	Hydranencephaly, micropenis	Neonatal VP shunt
							Apgars 41 55		1 year – diffuse hypotonia, depressed reflexes
4	35+1	2006	Intracranial hemorrhage	US-guided, transabdominal at 2 cm dilation, 17 gauge needle. 500 mL CSF removed	35+5	SVD	Male, 3,000 g	Severe ventriculomegaly, intracranial hemorrhage (Fig. 4a, b)	5 weeks – VP shunt inserted
							Apgars 81 95		2 years – global developmental delay
							​		5 years – moderate developmental delay, hemiplegia

SVD, spontaneous vaginal delivery; CSF, cerebrospinal fluid.

Long-Term Outcomes in Survivors

All four survivors were born by spontaneous vaginal delivery (Table 6). Two procedures were performed transvaginally using 22 G needles, while two were performed transabdominally with 17 G and 21 G needles. All survivors demonstrated NDI ranging from mild hemiplegia to severe cognitive delay, though one achieved university attendance despite mild cerebral palsy. All required ventriculoperitoneal shunts postnatally for ongoing hydrocephalus management.

Discussion

The evolution of cephalocentesis from an intrapartum procedure to a planned intervention represents a paradigm shift in modern obstetric practice. Our experience spanning nearly four decades demonstrates that when appropriately applied, specifically in cases where pregnancy termination has been decided upon due to lethal or serious fetal anomalies, cephalocentesis continues to offer the benefit of facilitating a vaginal delivery, thus avoiding the additional maternal morbidity associated with caesarean section in the index and subsequent pregnancies.

Our comparison of pre-2002 (n = 37) and 2002-onward (n = 33) cohorts reveals several important transitions in clinical practice. Prior to 2002, cephalocentesis was predominantly performed as an intrapartum procedure to facilitate vaginal delivery when severe hydrocephalus was diagnosed late or presented as an intrapartum complication. In contrast, the 2002-onward era reflects a more systematic approach with the integration of fetal sedation and analgesia in all cases, with the addition of fetal KCl prior to the procedure if acceptable to parents, ensuring that it be reserved only for cases where pregnancy termination has been determined to be appropriate. This evolution allows for a more controlled intervention that prioritizes maternal well-being while ensuring humane fetal management in such cases of lethal or seriously handicapping fetal anomalies [17, 18].

While improved prenatal diagnostics have significantly reduced the incidence of severe hydrocephalus presenting only late in pregnancy, our contemporary experience demonstrates that there continues to be an important role for this procedure in current obstetric practice. This is specifically in cases where patients present late to care with lethal or severe fetal anomalies, where pregnancy termination is being pursued, and where vaginal delivery is preferred to avoid the increased maternal morbidity associated with caesarean section. Rather than representing a failure of prenatal diagnosis, most recent cases arise from complex socioeconomic, healthcare access and cultural factors that delay initial presentation until the third trimester [19].

The universal presence of NDI among survivors (100%) underscores that this procedure should not be considered in cases where pregnancy continuation is desired. This finding aligns with meta-analyses showing poor neurodevelopmental outcomes in severe ventriculomegaly [20]. The fact that 91.8% of fetuses who did not receive KCl died perinatally further demonstrates the significant impact of this intervention and supports restricting its use to cases where pregnancy termination has already been determined to be appropriate due to lethal or very serious fetal anomalies.

The high rate of successful vaginal delivery (95.7%) with minimal maternal complications supports the procedure's clinical utility in cases of severe hydrocephalus that result in macrocephaly. Our experience demonstrates clear maternal benefits through the avoidance of caesarean section and its associated operative morbidity in the index and subsequent pregnancies, which is particularly important in these clinically complex cases where preservation of future reproductive potential is paramount.

The clinical decision-making framework for cephalocentesis has been well-established in the literature. Chervenak and McCullough delineated specific clinical scenarios where cephalocentesis could be considered to be medically appropriate, specifically restricting it to cases where fetal hydrocephalus was accompanied by severe anomalies incompatible with postnatal survival or characterized by the virtual absence of cognitive function and where the decision to terminate the pregnancy had already been made [14, 15, 21]. In such cases, prioritizing maternal health and avoiding unnecessary surgical risk through caesarean section aligns with beneficence-based obligations to the mother. It is critical to emphasize that this procedure should never be considered a therapeutic intervention for the fetus, but rather as a means to facilitate vaginal delivery, with the expectation that the fetus would not survive the procedure or subsequent labor.

Our study’s limitations include its retrospective design and extended timeframe encompassing significant evolution in both our diagnostic capabilities and technical approaches. The changing indications for the procedure over time create challenges in outcome comparison. Additionally, variable documentation and follow-up protocols over the study period may impact outcome assessment, particularly in earlier cases. The strengths of our study is that it is the largest series of cephalocentesis procedures (n = 70), with comprehensive long-term follow-up of all survivors across two tertiary centers over 38 years. The historical depth of this series provides unique insights into practice evolution while highlighting the persistent contemporary relevance of this procedure in carefully selected cases, particularly given ongoing global disparities in prenatal diagnosis and healthcare access.

Conclusion

This comprehensive 38-year experience demonstrates the significant evolution of cephalocentesis from an emergency intrapartum intervention to a carefully planned procedure with standardized protocols, reserved exclusively for cases with no expectation of intact postnatal survival. Our findings challenge the traditional assumption that cephalocentesis is universally lethal, with 8.2% survival when KCl is not administered, though all survivors exhibited significant NDI. As cases of severe hydrocephalus continue to present globally, particularly in resource-limited settings, institutions must maintain the capacity to manage these complex clinical scenarios through multidisciplinary team approaches that combine technical competency with compassionate care delivery. The primary therapeutic objective remains facilitating safe vaginal delivery while avoiding unnecessary caesarean-associated maternal morbidity. Given the rarity yet persistent clinical relevance of this procedure, preserving institutional knowledge and procedural expertise represents a critical challenge that may be addressed through innovative simulation-based training programs, ensuring that essential skills remain available for these rare but potentially life-saving interventions when appropriately indicated.

Acknowledgment

We acknowledge the contributions of the multidisciplinary teams involved in the care of these complex cases over the 38-year study period.

Statement of Ethics

This study protocol was reviewed and approved by the Research Ethics Board of Mount Sinai Hospital, Toronto, Canada, Approval No. 17-0321-C. The need for written informed consent was waived by the Research Ethics Board of Mount Sinai Hospital (Approval No. 17-0321-C) due to the retrospective nature of the study design and the use of anonymized patient data. This study was conducted in accordance with the World Medical Association Declaration of Helsinki.

Conflict of Interest Statement

Dr. Greg Ryan is a member of the journal's Editorial Board at the time of submission. The remaining authors declare no conflicts of interest.

Funding Sources

No external funding was received for this study.

Author Contributions

Conceptualization: C.W. and G.R. Data collection: E.N.K., E.H., A.A., P.M., and C.W. Data analysis: C.W. and Y.K. Writing manuscript: E.H., A.A., and C.W. Supervision: E.N.K., G.R., R.W., F.M.M., and S.S. Clinical consultation: D.C., N.A., G.S., J.K., and T.M. All authors critically revised and approved the final version.

Funding Statement

No external funding was received for this study.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request. The data are not publicly available due to privacy and ethical restrictions.