The use of a Fetal Pillow device at full-dilation cesarean delivery—maternal and neonatal outcomes: a retrospective study

Abstract

Purpose

Impacted fetal head at full-dilation cesarean delivery (CD) is a major cause of adverse maternal and neonatal outcomes. The Fetal Pillow is a device designed to reduce these complications. Our study aims to evaluate the outcomes of full-dilation CD with and without the use of Fetal Pillow.

Methods

This retrospective cohort study included full-dilation CDs performed from January 2018 to July 2023, at a single tertiary center. Indications for CDs were arrest of decent, fetal distress, and failed vacuum extraction. The study cohort included cases (Fetal Pillow group) matched to controls (without the use of Fetal Pillow) according to the indication to CD, in a 1:2 ratio. The study evaluated maternal outcomes as uterine incision extensions, maternal blood loss (ml), maternal postoperative infection, and length of hospitalization (days). Neonatal outcomes included NICU admissions, cord arterial blood pH, Apgar scores, respiratory distress, intubation, and seizures.

Results

The study included 138 patients, of them 46 in the Fetal Pillow group and 92 matched controls. Maternal baseline characteristics, including age, BMI, prior CDs, and obstetric complications, were similar between groups. No significant differences were observed in median surgery duration [55 (44–68) vs. 54 (42–65) min; p = 0.361] or fetal extraction time [6 (4–8) vs. 5.5 (3–8) min; p = 0.507]. Maternal outcomes, including rates of uterine incision extensions, blood loss, and length of hospitalization, were comparable between groups. However, NICU admissions were significantly lower in the Fetal Pillow group compared to controls (17.3% vs. 33.7%, p = 0.04). In multivariable logistic regression analysis, adjusting for parity, fetal head station and position, maternal age, prior CD, and neonatal birth weight, Fetal Pillow use was associated with reduced NICU admissions [adjusted odds ratio (aOR) 0.30; 95% CI 0.11–0.82; p = 0.019].

Conclusion

The use of Fetal Pillow for impacted fetal head during full-dilation CDs may reduce NICU admissions without adversely affecting maternal outcomes.

What does this study adds to clinical work

The use of the Fetal Pillow during full-dilation cesarean delivery was associated with reduced NICU admissions, without an increase in maternal morbidity. These findings suggest a potential neonatal benefit of the device in managing impacted fetal head.

Introduction

Full-dilation cesarean deliveries (CDs) have seen an increase in prevalence over the last decade, now accounting for up to 5% of all CDs [1, 2]. It is a significant cause of maternal and perinatal morbidity [3]. One major contributing factor to adverse outcomes is the presence of an impacted fetal head. It is reported in up to 63% of full-dilation CDs [4], and it can lead to difficult extraction since the fetal head is deeply engaged in the maternal pelvis. Maternal complications associated with full-dilation CD primarily involve extensions of the uterine incision [1] and excessive bleeding. Neonatal complications include hypoxic brain injury, respiratory distress, low Apgar scores, skeletal injuries, and increased rates of neonatal intensive care unit (NICU) admissions [5].

Several techniques have been suggested to facilitate elevation of the fetal head during delivery [6]. These include the ‘Push’ technique, where an assistant manually pushes the impacted fetal head through the vagina; and the “Pull technique” reverse breech extraction, which involves delivering the fetus by traction on the fetal feet [7].

The Fetal Pillow [CooperSurgical, Inc] is a medical device designed to elevate the fetal head during delivery. It is inserted into the vagina with sterile lubrication before surgery, with the balloon positioned posterior to the fetal head. Once in place, the balloon inflated with 180 ml of normal saline, facilitating the elevation of the fetal head to simplify extraction. Following delivery, the balloon is deflated and removed.

Evidence regarding the effectiveness of the Fetal Pillow remains inconclusive. While some studies suggest that its use reduces adverse outcomes, other research has shown no significant benefit. In addition, several reports have raised safety concerns, particularly when the device is used following failed instrumental delivery attempts [8]. Moreover, recent scrutiny has been directed toward the integrity of early studies supporting its efficacy, and several key publications were retracted [9, 10]. As described in a recent commentary, the Fetal Pillow was embedded in clinical practice without reliable supporting evidence and raised uncertainties about its clinical use [11]. These developments underscore the need for independent, high-quality research to clarify the clinical role of the device.

We conducted a retrospective case–control study to assess the maternal and neonatal outcomes associated with the use of the Fetal Pillow in three specific indications for full-dilation CD: arrest of descent, suspected of fetal distress based on non-reassuring fetal heart rate (NRFHR) monitor, and failed vacuum extraction.

Methods

This retrospective cohort study was conducted at a single tertiary medical center, between January 2017 and July 2023, and included women with a singleton pregnancy at term gestation (> 37 weeks of gestation) in the second stage of labor (full cervical dilation).

The study cohort included CDs performed at full dilation due to arrest of decent, suspected fetal distress, and failed vacuum extraction, with the fetal head at station 0 to + 2.

In the Fetal Pillow group, the device was used intraoperatively based on the senior obstetrician’s clinical judgment, experience, and familiarity with the device. Each CD was performed by two surgeons: at least one senior obstetrician, accompanied by either another senior obstetrician or a resident. The senior obstetrician inserted the device during surgical preparation to ensure consistent operator experience. The balloon was positioned in the posterior fornix beneath the fetal head and inflated with 180 ml of normal saline—the standard volume reported in most clinical studies—prior to the uterine incision. At the end of the procedure, the balloon was manually deflated and removed.

The control group included CDs performed at full dilation without the use of a Fetal Pillow. Controls were randomly selected from the hospital’s electronic medical record system, during the same time period, and were matched in a 1:2 ratio according to the indications for CD (arrest of decent, suspected fetal distress, and failed vacuum extraction).

Data collection

Data (including intraoperative management) were retrieved from the computerized electronic database of the delivery room and surgical reports. Maternal characteristics included: age, body mass index (BMI, kg/m²), parity, and pregnancy complications including gestational diabetes mellitus (GDM), hypertensive disorders (preeclampsia, chronic hypertension), and polyhydramnios.

Delivery and surgical characteristics assessed included gestational age at delivery, neonatal birth-weight (grams), fetal head position (OA/OP) and station (fetal head station during labor was assessed based on its position relative to the ischial spines), intrapartum fever (a rise in maternal body temperature above normal > 38 °C), labor duration (defined as the time from admission to the delivery room until the time of birth in minutes), decision-to-incision interval (min), extraction time (min)—the interval from skin incision to fetal extraction, and the total surgery time (min). Type of anesthesia was matched between groups.

Maternal adverse outcomes included uterine incision extension, clinical estimation of blood loss during the operation (in milliliters), need for blood transfusion, admission to the intensive care unit (ICU), postpartum infection, delta hemoglobin values (preoperative minus postoperative, and postoperative length of hospital stay (in days). Notably, according to departmental policy, ‘prolonged hospitalization’ was defined as a postoperative stay exceeding 3 days. Composite maternal complications included uterine incision extension, estimated blood loss > 1000 ml, need for blood transfusion and admission to the ICU.

Neonatal outcomes included: Apgar scores at 1 and 5 min, need for resuscitation following stimulation (including intermittent positive-pressure ventilation, continuous positive airway pressure, or intubation), cord arterial pH at delivery, birth trauma, neonatal encephalopathy, seizures, and neonatal intensive care unit (NICU) admissions.

Statistical analysis

Descriptive statistics were employed to characterize the study population. Categorical variables were presented as frequencies and percentages, while numerical variables were presented as mean ± standard deviation (SD) for normally distributed data or median with interquartile range (IQR) for ordinal or non-normally distributed data. Normality of continuous variables was assessed using histogram plots, Shapiro–Wilk test, and Kolmogorov–Smirnov test.

Univariate analysis was conducted to compare clinical and sociodemographic characteristics between participants who underwent CD with the use of a Fetal Pillow device and those who did not. For continuous variables with normal distribution, independent sample t test was used. For continuous variables with non-normal distribution and ordinal variables, Mann–Whitney U test was employed. For categorical variables, Chi-square test or Fisher’s exact test was used as appropriate.

Multivariable logistic regression models were constructed to examine the association between Fetal Pillow use during CD and maternal and neonatal postoperative outcomes. The regression models were adjusted for potential confounders (parity, fetal head station, fetal head position, maternal age, prior CD, and neonatal birth weight).

All statistical analyses were performed using SPSS Statistics version 25. A two-sided test significance level of p < 0.05 was used throughout the entire study.

Results

During the study period, there were approximately 37,500 deliveries; among them, 1875 (5%) had emergency CD. Out of these, 324 (17%) were performed at full dilation; of them, 46 patients underwent CDs with the use of Fetal Pillow (Fetal Pillow group) and 92 patients were selected as matched controls who did not receive the intervention (control group). The indications for CD in each group were as follows: 17.4% due to NRFHR, 39% due to arrest of fetal head decent, and 43.5% failed vacuum extraction.

Maternal and obstetric characteristics are summarized in Table 1. There were no between-group differences in maternal age (30.1 ± 5.8 vs. 30.8 ± 4.8 years, p = 0.469), or BMI (29.2 ± 4.6 vs. 29.7 ± 5.4 kg/m², p = 0.660). The groups were similar in rates of pregnancy complications (8.7% vs. 17.4%, p = 0.171) and previous CD (2.2% vs 6.5%, (p = 0.424). However, there was significant difference in parity: 95.7% were nullipara in the FP group, compared to 78.3% in the controls, p = 0.009.

Table 1.

Maternal characteristics

Variable	Fetal Pillow group (n = 46)	Control group (n = 92)	p value
Maternal age (years)	30.1 ± 5.8	30.8 ± 4.8	0.469
BMI (kg/m2)	29.2 ± 4.6	29.7 ± 5.4	0.660
Pregnancy complications	4 (8.7)	16 (17.4)	0.171
Gravidity	1 (1–1.25)	1 (1–2)	0.070
Parity	0 (0–0)	0 (0–0)	0.010
Nulliparity	44 (95.7)	72 (78.3)	0.009
Previous CD	1 (2.2)	6 (6.5)	0.424

Bold values indicate statistically significant differences between groups (p 0.05)

Data are shown as number (%), mean ± standard deviation (SD) or median (inter-quartile range) as appropriate

BMI body mass index, CD cesarean delivery

Labor and surgical characteristics are presented in Table 2. Labor characteristics were similar with no differences in gestational age (39.9 weeks vs. 39.9 weeks, p = 0.511), neonatal birthweights (3274 ± 407 vs. 3397 ± 375 g, p = 0.080), premature rupture of membranes rates (32.6% vs. 33.7%, p = 0.898), labor duration (982 vs. 998 min, p = 0.841), rate of epidural/spinal analgesia and the median fetal head station at delivery (plus 1.5 vs. plus 1, p = 0.313). Surgical characteristics were also similar, with no differences in median decision to incision interval (10.5 min vs. 13 min, p = 0.254), median surgery time (55 min vs 54 min, p = 0.361), and the median time interval from incision to fetal extraction (6 min vs. 5.5 min, respectively (p = 0.507).

Table 2.

Labor and surgery characteristics

	Fetal Pillow group (n = 46)	Control group (n = 92)	p value
Gestational age	39.9 (39.0–40.7)	39.9 (39.1–40.6)	0.511
PROM	15 (32.6)	31 (33.7)	0.898
Fetal head station (cm)	1.5 (1–2)	1 (0–2)	0.313
Fetal position
OA	26 (61.9)	23 (27.1)	< 0.001
OP	16 (38.1)	62 (72.9)
IPF	14 (30.4)	24 (26.1)	0.590
First stage of labor (min)	712 (538–1172)	791 (442–1114)	0.995
Second stage of labor (min)	217 (133–240)	198 (123–257)	0.580
Labor duration (min)	982 (759–1331)	998 (640–1343)	0.841
Neonatal birth weight (g)	3274 ± 407	3397 ± 375	0.080
Epidural/spinal analgesia	38 (82.6)	76 (82.6)	1.00
General anesthesia	8 (17.4)	16 (17.4)	1.00
Total surgery time (min)	55 (44–68)	54 (42–65)	0.361
Decision to incision (min)	10.5 (5.75–15)	13 (6–18.5)	0.254
Extraction time (min)	6 (4–8)	5.5 (3–8)	0.507

Bold values indicate statistically significant differences between groups (p 0.05)

Data are shown as number (%), mean ± standard deviation (SD) or median (inter-quartile range) as appropriate

PROM pre-labor rupture of membrane; fetal head station in relation to ischial spine at the time of the surgery, IPF intrapartum fever; extraction time—incision to delivery time

Adverse maternal and neonatal outcomes are presented in Table 3. There were no between-group differences in the rates of uterine incision extensions (30.4% vs. 21.7%, p = 0.264), estimated maternal blood loss > 1000 ml (2.2% vs. 4.3%, p = 0.665), blood products transfusion requirements (p = 0.601), discharge hemoglobin levels (10.1 ± 1.3 vs. 10.0 ± 1.4 g/dl, p = 0.493), prolonged hospitalization > 3 days (43.5% vs. 37.4%, p = 0.489), puerperal fever (2.2% vs. 5.4%, p = 0.663), or ICU admissions (0% vs. 1.1%, p = 1.00). Composite adverse maternal outcome did not differ between the groups (30.4% in the Fetal Pillow group vs. 23.9% in controls, p = 0.411).

Table 3.

Adverse maternal and neonatal outcomes

	Fetal Pillow group (n = 46)	Control group (n = 92)	p value
Maternal outcomes
Extensions of uterine incision	14 (30.4)	20 (21.7)	0.264
Bleeding amount, ml	400 (300–500)	300 (300–400)	0.229
Bleeding > 1000 ml	1 (2.2)	4 (4.3)	0.665
Need for blood products	2 (4.3)	2 (2.2)	0.601
Discharge Hb level (g/dl)	10.1 ± 1.3	10.0 ± 1.4	0.493
Delta Hb > 3 g/dl	20 (43.5)	37 (40.7)	0.752
Postoperative hospitalization > 3 days	20 (43.5)	34 (37.4)	0.489
Puerperal fever	1 (2.2)	5 (5.4)	0.663
Re-laparotomy	0 (0.0)	1 (1.1)	1.00
ICU admission	0 (0.0)	1 (1.1)	1.00
Composite adverse outcome	14 (30.4)	22 (23.9)	0.411
Neonate outcomes
5-min Apgar < 7	1 (2.2)	4 (4.3)	0.665
Cord pH < 7.2	16 (35.6)	36 (39.6)	0.651
NICU	8 (17.4)	31 (33.7)	0.045
Respiratory distress	11 (23.9)	32 (35.6)	0.167
Intubation	3 (6.5)	8 (8.9)	0.750
Seizures	0 (0.0)	1 (1.1)	1.00

Bold values indicate statistically significant differences between groups (p 0.05)

Data are shown as number (%), mean ± standard deviation (SD) or median (inter-quartile range) as appropriate

ICU intensive care unit, NICU neonatal intensive care unit

Regarding neonatal outcomes (Table 3), NICU admission rates were significantly lower in the Fetal Pillow group compared to controls (17.4% vs. 33.7%, p = 0.045). No significant differences were found between the groups in other neonatal outcomes as the rates of low 5-min Apgar scores < 7 (p = 0.665), cord arterial pH < 7.2 (35.6% vs. 39.6%, p = 0.651), respiratory distress (23.9% vs. 35.6%, p = 0.167), intubation (6.5% vs. 8.9%, p = 0.750), seizures (0% vs. 1.1%, p = 1.00), or the need for therapeutic neonatal cooling (4.3% vs. 6.7%, p = 0.717).

Multivariable logistic regression (Table 4) was performed adjusting for: parity, fetal head station, fetal head position, maternal age, prior CD, and neonatal birth weight. The use of Fetal Pillow remained significantly associated with reduced NICU admissions (aOR 0.30, 95% CI 0.11–0.82, p = 0.019).

Table 4.

Multivariable regression models for maternal and neonatal adverse outcomes

	aOR	95% CI	p value
Maternal outcomes
Extension of uterine incision	2.04	0.78–5.30	0.144
Bleeding > 1000 ml	0.13	0.01–4.67	0.261
Delta Hb > 3 g/dl	0.86	0.37–1.96	0.715
Puerperal fever	0.31	0.03–3.08	0.315
Hospitalization > 3 days	1.25	0.50–3.13	0.642
Composite adverse outcome	1.76	0.70–4.47	0.232
Neonate outcomes
5 min Apgar < 7	0.47	0.05–4.88	0.529
pH < 7.2	0.55	0.22–1.37	0.196
NICU	0.34	0.12–0.95	0.039
Respiratory distress	0.55	0.22–1.40	0.207
Intubation	0.99	0.21–4.73	0.995

Bold values indicate statistically significant differences between groups (p 0.05)

Multivariable logistic regression models were adjusted for potential confounders identified in the univariate analysis—parity, history of previous surgery, neonatal birth weight, and CD indication. The reference group was the controls

aOR adjusted odds ratio, CI confidence interval, NICU neonatal intensive care unit

Discussion

Main findings

The current study presents the usage of Fetal Pillow in cesarean deliveries performed at full cervical dilation, a clinical scenario often complicated by impacted fetal head. In this retrospective case–control study, the use of Fetal Pillow was associated with a lower rate of NICU admissions and with no significant differences in adverse maternal outcomes.

There are several methods for fetal extraction during a fully dilated cesarean delivery, a surgery that is associated with increased risks for adverse maternal and neonatal outcomes. Yet, the role of the Fetal Pillow as another possible method during second-stage CDs is unknown with different and diverse reports. Sacre et al. [12] reported that the use of Fetal Pillow was associated with reduced uterine extensions and NICU admissions, although other studies such as Hanley et al. and Sadler et al. showed no statistically significant improvement in either maternal or neonatal outcomes with Fetal Pillow use [13, 14]. A randomized controlled trial by Lassey et al. evaluated the use of a cephalic elevation device during second-stage cesarean deliveries and reported a significantly shorter time from hysterotomy to delivery in the device group (31 vs. 54 s), as well as a non-significant trend toward fewer uterine extensions. It did not demonstrate differences in neonatal outcomes [15]. A recent meta-analysis also concluded that while the Fetal Pillow may reduce incision to delivery time and uterine extensions, the evidence regarding neonatal benefits remains inconsistent [16].

In the current study, we observed a modest fetal benefit—a lower rate of NICU admission in the Fetal Pillow group (aOR 0.30, 95% CI 0/11–0.82, p = 0.019). Importantly, our study did not demonstrate increased rates of fetal trauma or adverse neonatal events with Fetal Pillow use. This contrasts the findings of Lila et al., who reported more fetal injuries, particularly following failed vacuum attempts [8].

In the current study, the use of the Fetal Pillow was not associated with improvement in other neonatal outcomes. Measures such as 5-min Apgar scores, umbilical cord pH values, respiratory distress, and encephalopathy did not differ between groups. These findings align with previous studies reporting that, while the device may facilitate fetal head elevation, it does not consistently translate into broad neonatal benefit. This further supports the conclusion that any neonatal advantage associated with Fetal Pillow use appears limited and should be interpreted with caution.

Maternal outcomes were also comparable between groups across all measured parameters, with no significant benefit observed with Fetal Pillow use. The findings were consistent both in univariate analyses and in multivariable regression models adjusted for clinically relevant confounders, none of which demonstrated an association between the Fetal Pillow and reduced maternal morbidity. This pattern persisted even in subgroup analyses stratified by CD indication. The lack of maternal benefit aligns with several previous studies reporting that, while the Fetal Pillow may facilitate cephalic elevation, this technical advantage does not consistently translate into improved maternal surgical outcomes. Nevertheless, it is reassuring, however, that in our cohort, the operative timing parameters were similar between groups, with no differences in either the decision-to-incision interval or extraction time, indicating that the use of the Fetal Pillow did not introduce any procedural delays.

Notably, the Fetal Pillow group included a significantly higher proportion of nulliparous women (95.7%) compared with the control group (78.3%; p = 0.009). This difference may confound the findings, as parity influences both the ease of fetal head disimpaction and the degree of manipulation required. Nulliparous women generally have a less compliant birth canal, which may make fetal head elevation more difficult and impact maternal and neonatal outcomes. Although parity was included in the multivariable regression model to reduce this potential bias, residual confounding cannot be fully ruled out.

Cesarean deliveries performed at full cervical dilation are well documented to carry increased risks, including uterine atony, extensions of the uterine incision, prolonged maternal hospitalization, and higher rates of infection-related complications [17]. These deliveries are also associated with adverse neonatal outcomes such as higher rates of NICU admissions, Apgar scores below 7 at 5 min, and even neonatal death [18]. Clinicians managing such complex scenarios must be equipped with a variety of strategies to optimize both maternal and neonatal outcomes. Further large-scale prospective studies are necessary to better evaluate the potential benefits of interventions like the Fetal Pillow in this context.

Strengths and limitations

Our study has several strengths. First, it is a case–control study, including indication-matched controls. All CDs were performed in a single medical center with similar treatment protocols and detailed documentation. A notable strength of this study is its temporal stability. Although the study spanned 5 years, no significant temporal changes occurred at our institution that would be expected to influence maternal or neonatal outcomes. The same senior obstetric team supervised all second-stage cesarean deliveries throughout the entire period, with no changes in staffing or structure. Likewise, no new neonatal care protocols, technologies, or organizational changes were implemented in the NICU during these years. Therefore, the likelihood of time-related bias is minimal.

The limitations of the current study should be acknowledged as well. First, the sample size is relatively modest, which reduces the statistical power to detect uncommon maternal or neonatal adverse outcomes. Although previous studies evaluating this intervention have reported comparable cohort sizes, our limited sample restricts the ability to identify rare complications with confidence. Second, the retrospective design is a key limitation. Retrospective data may suffer from incomplete documentation, and information on extraction techniques in the control group was insufficient. Management of the impacted fetal head was not documented, so the use of digital vaginal disimpaction cannot be confirmed or excluded. Third, conducting the study at a single tertiary institution may limit the generalizability of the findings to other settings with different clinical practices or patient populations. Fourth, the decision to use the Fetal Pillow was made at the discretion of the attending obstetrician, which may introduce selection bias, as clinicians may have selectively chosen the device in cases where they anticipated more difficult fetal head elevation. In addition, long-term maternal and neonatal outcomes were not evaluated.

The reversal of NICE recommendations and the withdrawal of a Royal College of Obstetricians and Gynecologists scientific paper further underscore the fragility of the current evidence base. Our study adds to the growing body of literature by providing additional real-world data, although the limitations inherent to its retrospective design must be considered.

Conclusion

In conclusion, the use of the Fetal Pillow during full-dilation cesarean deliveries may reduce the need for neonatal intensive care unit admission with no additional increase in maternal morbidity. Further studies are required to determine its optimal role in managing impacted fetal head and improving both maternal and neonatal outcomes.

Author contributions

M Ronen: project development, data collection, data analysis, manuscript writing. L Segev: project development, data collection, data analysis, manuscript writing. C Porat: data collection, data analysis, manuscript editing. M Moskovich: project development, data analysis, manuscript editing. M Kovo: data analysis, manuscript editing. M Betser: project development, manuscript editing. All authors read and approved the final manuscript.

Funding

The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Declarations

Conflict of interest

The authors declare no competing interests.

Ethical approval

The study was approved by the Medical Center Ethics Committee in Shamir Medical Center. approval number 0198-23-ASF. Due to the retrospective nature of the data collection, individual informed consent was not required.