Maternal and neonatal morbidity in relation to the instrument used for mid-cavity rotational operative vaginal delivery: a prospective cohort study

Pitfalls in the diagnostics of shoulder dystocia: an analysis based on the scrutiny of 2274 deliveries

PURPOSE

Shoulder dystocia is an obstetric emergency with severe complications. Our objective was to evaluate the major pitfalls in the diagnostics of shoulder dystocia, diagnostic descriptions documented in medical records, use of obstetric maneuvers, and their correlations to Erb's and Klumpke's palsy and the use of ICD-10 code 066.0.

METHODS

A retrospective, register-based case-control study included all deliveries (n = 181 352) in Hospital District of Helsinki and Uusimaa (HUS) area in 2006-2015. Potential shoulder dystocia cases (n = 1708) were identified from the Finnish Medical Birth Register and the Hospital Discharge Register using ICD-10 codes O66.0, P13.4, P14.0, and P14.1. After thorough assessment of all medical records, 537 shoulder dystocia cases were confirmed. Control group consisted of 566 women without any of these ICD-10 codes.

RESULTS

The pitfalls in the diagnostic included suboptimal following of guidelines for making the diagnosis of shoulder dystocia, subjective interpretation of diagnostic criteria, and inexact or inadequate documentation in medical records. The diagnostic descriptions in medical record were highly inconsistent. The use of obstetric maneuvers was suboptimal among shoulder dystocia cases (57.5%). Overall, the use of obstetric maneuvers increased during the study period (from 25.7 to 97.0%, p < 0.001), which was associated with decreasing rate of Erb's palsy and increasing use of ICD-10 code O66.0.

CONCLUSION

There are diagnostic pitfalls, which could be addressed by education regarding shoulder dystocia guidelines, by improved use obstetric maneuvers, and more precise documentation. The increased use of obstetric maneuvers was associated with lower rates of Erb's palsy and improved coding of shoulder dystocia.

Assisted vaginal birth in 21st century: current practice and new innovations

Assisted vaginal birth rates are falling globally with rising cesarean delivery rates. Cesarean delivery is not without consequence, particularly when carried out in the second stage of labor. Cesarean delivery in the second stage is not entirely protective against pelvic floor morbidity and can lead to serious complications in a subsequent pregnancy. It should be acknowledged that the likelihood of morbidity for mother and baby associated with cesarean delivery increases with advancing labor and is greater than spontaneous vaginal birth, irrespective of the method of operative birth in the second stage of labor. In this article, we argue that assisted vaginal birth is a skilled and safe option that should always be considered and be available as an option for women who need assistance in the second stage of labor. Selecting the most appropriate mode of birth at full dilatation requires accurate clinical assessment, supported decision-making, and personalized care with consideration for the woman's preferences. Achieving vaginal birth with the primary instrument is more likely with forceps than with vacuum extraction (risk ratio, 0.58; 95% confidence interval, 0.39-0.88). Midcavity forceps are associated with a greater incidence of obstetric anal sphincter injury (odds ratio, 1.83; 95% confidence interval, 1.32-2.55) but no difference in neonatal Apgar score or umbilical artery pH. The risk for adverse outcomes is minimized when the procedure is conducted by a skilled accoucheur who selects the most appropriate instrument likely to achieve vaginal birth with the primary instrument. Anticipation of potential complications and dynamic decision-making are just as important as the technique for safe instrument use. Good communication with the woman and the birthing partner is vital and there are various recommendations on how to achieve this. There have been recent developments (such as OdonAssist) in device innovation, training, and strategies for implementation at a scale that can provide opportunities for both improved outcomes and reinvigoration of an essential skill that can save mothers' and babies' lives across the world.

Management of impacted fetal head at cesarean delivery

Globally, more than 1 in 5 women give birth by cesarean delivery, and at least 5% of these births are at full cervical dilatation. In these circumstances, and when labor has been prolonged in the first stage of labor, the fetal head can become low and wedged deep in the woman's pelvis, making it difficult to deliver the baby. This emergency is known as impacted fetal head. These are technically challenging births associated with serious risks to both the woman and the baby. The difficulty in disimpacting the fetal head increases maternal risks of hemorrhage and injury to adjacent organs and may have long-term consequences for future pregnancies. In addition, there can be associated neonatal consequences, such as skull fractures, brain hemorrhage, hypoxic brain injury, and, rarely, perinatal death. Globally, maternity staff are increasingly encountering this emergency, with studies in the United Kingdom suggesting that impacted fetal head may complicate as many as 1 in 10 emergency cesarean deliveries. Moreover, there has been a sharp increase in reports of perinatal brain injuries associated with impaction of the fetal head at cesarean delivery. When an impacted fetal head occurs, the maternity team can employ a range of approaches to help deliver the fetal head, including an assistant (another obstetrician or midwife) pushing the head up from the vagina, delivering the baby feet first (reverse breech extraction), administering tocolysis to relax the uterus, and using a balloon cephalic elevation device (Fetal Pillow) to elevate the baby's head. However, there is currently no consensus on how best to manage these births, resulting in a lack of confidence among maternity staff, variable practice, and potentially avoidable harm in some circumstances. This article examined the evidence for the prevention and management of this critical obstetrical emergency and outlined recommendations for best practices and training.

Maternal and neonatal complications of shoulder dystocia with a focus on obstetric maneuvers: A case-control study of 1103 deliveries

INTRODUCTION

Shoulder dystocia is a severe obstetric emergency that can cause substantial neonatal and maternal complications. This study aims to assess the performed obstetric maneuvers and their frequency, success, and association with maternal and neonatal complication rates.

MATERIAL AND METHODS

The study population was collected among all deliveries in the Hospital District of Helsinki and Uusimaa between 2006 and 2015 (n = 181 352) by searching for ICD-10 codes for shoulder dystocia, brachial plexus injury and clavicle fracture. Shoulder dystocia cases (n = 537) were identified by reviewing the medical records. Shoulder dystocia cases treated with one or two maneuvers were compared with those treated with at least three. Medical records of a matched control group constituting of 566 parturients without any of the forementioned ICD-10 codes were also scrutinized.

RESULTS

Using the four most common obstetric maneuvers (McRoberts maneuver, suprapubic pressure, rotational maneuvers, the delivery of the posterior arm) significantly increased during the study period with individual success rates of 61.0%, 71.9%, 68.1% and 84.8%, respectively. Concurrently, the rate of brachial plexus injury and combined neonatal morbidity significantly declined from 50% to 24.2% (p = 0.02) and from 91.4% to 48.5% (p < 0.001). Approximately 75% of shoulder dystocia cases treated with maneuvers were resolved by the McRoberts maneuver and/or suprapubic pressure, but each of the four most performed maneuvers significantly increased the cumulative success rate individually and statistically (p < 0.001). The rates of brachial plexus injury and combined neonatal morbidity were at their highest (52.9% and 97.8%) when none of the maneuvers were performed and at their lowest when two maneuvers were performed (43.0% and 65.4%). The increasing number (≥3) of maneuvers did not affect the combined maternal or neonatal morbidity or brachial plexus injury but increased the risk for third- or fourth-degree lacerations (odds ratio 2.91, 95% confidence interval 1.17 to 7.24).

CONCLUSIONS

The increased use of obstetric maneuvers during the study period was associated with decreasing rates of neonatal complications; conversely, the lack of obstetric maneuvers was associated with the highest rate of neonatal complications. These emphasize the importance of education, maneuver training and urgently performing shoulder dystocia maneuvers according to the international protocol guidelines.

A prospective study on neonatal ophthalmic injuries associated with forceps delivery

BACKGROUND

Assisted delivery by forceps is needed to expedite vaginal delivery in certain maternal and fetal conditions. The aim of this study was to evaluate the incidence and the extent of ophthalmological injuries in neonates after forceps delivery.

METHODS

Women with cephalic fetuses delivered vaginally by forceps from July 2020 to June 2022 were recruited prospectively. Ophthalmologists would be consulted when there were signs of external ophthalmic injuries, such as periorbital forceps marks or facial bruising. Demographic data, pregnancy characteristics, delivery details, and perinatal outcomes were evaluated to identify any associated risk factors for neonatal ophthalmological injuries.

RESULTS

A total of 77 forceps deliveries were performed in the study period, in which 20 cases (26%) required ophthalmological consultations. There were more right or left occipital fetal head positions in the group requiring ophthalmological assessment than those that did not require assessment (35% vs 12.3% [P = 0.023]). The degree of moulding of the fetal head was more marked in the former group (65% vs 28% [P = 0.001]). The overall incidence of detectable ophthalmological lesions was 16.9% (13/77). All ophthalmic injuries were mild, and most resolved with conservative management.

CONCLUSIONS

In our study cohort, external ophthalmic injuries were common after forceps delivery. We recommended ophthalmological consultation in newborns delivered by forceps with evidence of compressive trauma to rule out serious ophthalmological trauma.

Maternal and neonatal complications following Kielland's rotational forceps delivery: A systematic review and meta-analysis

BACKGROUND

There is conflicting evidence regarding the safety of Kielland's rotational forceps delivery (KRFD) in comparison with other modes of delivery for the management of persistent fetal malposition in the second stage of labour.

OBJECTIVES

To derive estimates of risks of maternal and neonatal complications following KRFD, compared with rotational ventouse delivery (RVD), non-rotational forceps delivery (NRFD) or a second-stage caesarean section (CS), from a systematic review and meta-analysis of the literature.

SEARCH STRATEGY

Standard search methodology, as recommended by the Cochrane Handbook for Systematic Reviews of Interventions.

SELECTION CRITERIA

Case series, prospective or retrospective cohort studies and population-based studies.

DATA COLLECTION AND ANALYSIS

A meta-analysis using a random-effects model was used to derive weighted pooled estimates of maternal and neonatal complications.

MAIN RESULTS

Thirteen studies were included. For postpartum haemorrhage there was no significant difference between Kielland's and ventouse delivery; the rate was lower in Kielland's delivery compared with non-rotational forceps (RR 0.79, 95% CI 0.65-0.95) and second-stage CS (RR 0.45, 95% CI 0.36-0.58). There were no differences in the rates of anal sphincter injuries or admission to neonatal intensive care. Rates of shoulder dystocia were higher with Kielland's delivery compared with ventouse delivery (RR 1.79, 95% CI 1.08-2.98), but rates of neonatal birth trauma were lower (RR 0.49, 95% CI 0.26-0.91). There were no differences seen in the rates of 5-min APGAR score < 7 between Kielland's delivery and other instrumental births, but they were lower when compared with second-stage CS (RR 0.47, 95% CI 0.23-0.97).

CONCLUSIONS

Kielland's rotational forceps delivery is a safe option for the management of fetal malposition in the second stage of labour.

Prospective assessment of vacuum deliveries from midpelvic station in a tertiary care university hospital: Frequency, failure rates, labor characteristics and maternal and neonatal complications

BACKGROUND

Midpelvic vacuum extractions are controversial due to reports of increased risk of maternal and perinatal morbidity and high failure rates. Prospective studies of attempted midpelvic vacuum outcomes are scarce. Our main aims were to assess frequency, failure rates, labor characteristics, maternal and neonatal complications of attempted midpelvic vacuum deliveries, and to compare labor characteristics and complications between successful and failed midpelvic vacuum deliveries.

STUDY DESIGN

Clinical data were obtained prospectively from all attempted vacuum deliveries (n = 891) over a one-year period with a total of 6903 births (overall cesarean section rate 18.2% (n = 1258). Student's t-test, Mann-Whitney U-test or Chi-square test for group differences were used as appropriate. Odds ratios and 95% confidence intervals are given as indicated. The uni- and multivariable analysis were conducted both as a complete case analysis and with a multiple imputation approach. A p-value of <0.05 was considered statistically significant.

RESULTS

Attempted vacuum extractions from midpelvic station constituted 36.7% (n = 319) of all attempted vacuum extractions (12.9% (n = 891) of all births). Of these 319 midpelvic vacuum extractions, 11.3% (n = 36) failed and final delivery mode was cesarean section in 86.1% (n = 31) and forceps in the remaining 13.9% (n = 5). Successful completion of midpelvic vacuum by 3 pulls or fewer was achieved in 67.1%. There were 3.9% third-degree and no fourth-degree perineal tears. Cup detachments were associated with a significantly increased failure rate (adjusted OR 6.13, 95% CI 2.41-15.56, p< 0.001).

CONCLUSION

In our study, attempted midpelvic vacuum deliveries had relatively low failure rate, the majority was successfully completed within three pulls and they proved safe to perform as reflected by a low rate of third-degree perineal tears. We provide data for nuanced counseling of women on vacuum extraction as a second stage delivery option in comparable obstetric management settings with relatively high vacuum delivery rates and low cesarean section rates.

Kielland's rotational forceps delivery: comparison of maternal and neonatal outcomes with pregnancies delivering by non-rotational forceps

We compared complications in pregnancies that had Kielland's rotational forceps delivery (KRFD) with non-rotational forceps delivery (NRFD). Maternal outcomes included post-partum haemorrhage (PPH) and obstetric anal sphincter injury (OASIS); neonatal outcomes included admission to neonatal intensive care unit (NICU), 5-minute Apgar scores <7, hypoxic ischaemic encephalopathy (HIE), jaundice, shoulder dystocia and birth trauma. The study population included 491 (2.1%) requiring KRFD, 1,257 (5.3%) requiring NRFD and 22,111 (93.0%) that had SVD. In pregnancies with NRFD compared to KRFD, there was higher incidence of OASIS (8.5% vs. 4.7%; p = .006) and a non-significant increased trend for PPH (15.0% vs. 12.4%; p = .173). There was no significant difference in rates of admission to NICU (p = .628), 5-minute Apgar score <7 (p = .375), HIE (p = .532), jaundice (p = .809), severe shoulder dystocia (p = .507) or birth trauma (p = .514). Our study demonstrates that KRFD has lower rates of maternal complications compared to NRFD whilst the rates of neonatal complications are similar.IMPACT STATEMENTWhat is already known on this subject? Kielland's rotational forceps is used for achieving vaginal delivery in pregnancies with failure to progress in second stage of labour secondary to fetal malposition. The use of Kielland's forceps has significantly declined in the last few decades due to concerns about an increased risk of maternal and neonatal complications, despite the absence of any major studies demonstrating this increased risk.What do the results of this study add? There are some studies which compare the risks in pregnancies delivering by Kiellands forceps with rotational ventouse deliveries but there is limited evidence comparing the risks of rotational with non-rotational forceps deliveries. Our study compares the major maternal and neonatal complications in a large cohort of pregnancies undergoing rotational vs. non-rotational forceps deliveries.What are the implications of these findings for clinical practice and/or further research? The results of our study demonstrate that maternal and neonatal complications in pregnancies delivering by Kielland's rotational forceps undertaken by appropriately trained obstetricians are either lower or similar to those delivering by non-rotational forceps. Consideration should be given to ensure that there is appropriate training provided to obstetricians to acquire skills in using Kielland's forceps.

Association between Neuraxial Labor Analgesia and Neonatal Morbidity after Operative Vaginal Delivery

BACKGROUND

Up to 84% of women who undergo operative vaginal delivery receive neuraxial analgesia. However, little is known about the association between neuraxial analgesia and neonatal morbidity in women who undergo operative vaginal delivery. The authors hypothesized that neuraxial analgesia is associated with a reduced risk of neonatal morbidity among women undergoing operative vaginal delivery.

METHODS

Using United States birth certificate data, the study identified women with singleton pregnancies who underwent operative vaginal (forceps- or vacuum-assisted delivery) in 2017. The authors examined the relationships between neuraxial labor analgesia and neonatal morbidity, the latter defined by any of the following: 5-min Apgar score less than 7, immediate assisted ventilation, assisted ventilation greater than 6 h, neonatal intensive care unit admission, neonatal transfer to a different facility within 24 h of delivery, and neonatal seizure or serious neurologic dysfunction. The authors accounted for sociodemographic and obstetric factors as potential confounders in their analysis.

RESULTS

The study cohort comprised 106,845 women who underwent operative vaginal delivery, of whom 92,518 (86.6%) received neuraxial analgesia. The proportion of neonates with morbidity was higher in the neuraxial analgesia group than the nonneuraxial group (10,409 of 92,518 [11.3%] vs. 1,271 of 14,327 [8.9%], respectively; P < 0.001). The unadjusted relative risk was 1.27 (95% CI, 1.20 to 1.34; P < 0.001); after accounting for confounders using a multivariable model, the adjusted relative risk was 1.19 (95% CI, 1.12 to 1.26; P < 0.001). In a post hoc analysis, after excluding neonatal intensive care unit admission and neonatal transfer from the composite outcome, the effect of neuraxial analgesia on neonatal morbidity was not statistically significant (adjusted relative risk, 1.07; 95% CI, 1.00 to 1.16; P = 0.054).

CONCLUSIONS

In this population-based cross-sectional study, a neonatal benefit of neuraxial analgesia for operative vaginal delivery was not observed. Confounding by indication may explain the observed association between neuraxial analgesia and neonatal morbidity, however this dataset was not designed to evaluate such considerations.

EDITOR’S PERSPECTIVE

Intrapartum ultrasound during rotational forceps delivery: a novel tool for safety, quality control, and teaching

BACKGROUND

Operative vaginal delivery and, in particular, rotational forceps delivery require extensive training, specific skills, and dexterity. Performed correctly, it can reduce the need for difficult late second-stage cesarean delivery and its associated complications. When rotation to occiput anterior position is achieved, pelvic trauma and anal sphincter injury commonly associated with direct delivery from occiput posterior positions may be avoided.

OBJECTIVE

We report the original and novel use of real-time intrapartum ultrasound simultaneously during Kielland's rotational forceps delivery to monitor correct execution and increase maternal safety.

STUDY DESIGN

This is a prospective observational study performed at the Charité University Hospital in Berlin between 2013 and 2018. Simultaneous, real-time, intrapartum suprapubic ultrasound during Kielland's rotational forceps deliveries were performed in a series of laboring women with normal fetuses and arrest of labor in the late second stage and with a fetal head malposition, requiring operative vaginal delivery. In addition to vaginal palpation for head station, rotation, and asynclitism, intrapartum ultrasound was also used to objectively determine head station, head direction, and midline angle. The operator was not blinded to the ultrasound findings. The delivering obstetrician examined the woman and performed the delivery. An assistant, trained in intrapartum ultrasound, placed a curved-array transducer transversely in the midline just above the pubic bone to display the forceps blades being applied and the rotation of the fetal head in occiput anterior position.

RESULTS

In all 32 laboring women included in the study, the blades were applied correctly and the fetal heads successfully rotated to an occiput anterior position with direct ultrasound confirmation, and vaginal delivery was achieved. There were no cases of difficult application, repeat application, slippage of the blades, or rotation of the fetal head in the wrong direction. Maternal outcomes showed no vaginal tears, cervical tears, or postpartum hemorrhage >500 mL. There was 1 case of third-degree perineal tear (3a). Neonatal outcomes included mild hyperbilirubinemia (n=1), small cephalohematoma conservatively managed (n=1), and early-onset group B streptococcus sepsis secondary to maternal colonization (n=1). There were no neonatal deaths.

CONCLUSIONS

Ultrasound guidance during Kielland's rotational forceps delivery is an original and novel approach. We describe the use of intrapartum ultrasound in assessing fetal head station and position and also to simultaneously and objectively monitor performance of rotational forceps delivery. Intrapartum ultrasound enhances operator confidence and, possibly, patient safety. It is a valuable adjunct to obstetrical training and can improve learning efficiency. Real-time ultrasound guidance of fetal head rotation to occiput anterior position with Kielland's forceps may also protect the perineum and reduce anal sphincter injury. This novel approach can lead to a renaissance in the safe use of Kielland's forceps.

Comparison of perinatal outcomes for all modes of second stage delivery in obstetric theatres: a retrospective observational study

OBJECTIVE

To compare rates of vaginal delivery and adverse outcomes of instrumental delivery trials in obstetric theatre compared to primary emergency full dilation caesarean section.

DESIGN

Retrospective cohort study.

SETTING

University teaching hospital.

POPULATION

Women with singleton, non-anomalous, pregnancy undergoing instrumental delivery trial in obstetric theatre.

METHODS

Data were collected from consecutive cases during 2014 until 2018 using clinical records. Multivariate regression analysis was used comparing outcomes per first delivery method.

MAIN OUTCOME MEASURES

Primary outcome was completion of vaginal delivery between all methods of instrumental delivery. Secondary outcome was a composite of immediate perinatal adverse outcomes for instrumental delivery modes and primary full dilation caesarean section.

RESULTS

From 971 deliveries analysed: ventouse delivery was significantly less likely to achieve vaginal delivery compared with Keilland's forceps delivery (odds ratio [OR] 0.42, 95% CI 0.22-0.79). Once confounding factors were adjusted for, adverse outcome rates were less frequent in the Keilland's forceps group than with primary full dilation caesarean section (OR 0.37, 95% CI 0.16-0.81); however, the receiver operating characteristic curve produced from this model demonstrated a low predictive value (AUC 0.64).

CONCLUSIONS

Attempting instrumental delivery in delivery suite theatre, as an alternative to primary emergency full dilation caesarean section, is both reasonable and safe. In this study, ventouse delivery performed poorly in comparison with other modes of instrumental delivery. Further research in the form of randomised controlled trials to identify the optimal mode of second stage delivery is paramount.

TWEETABLE ABSTRACT

Instrumental delivery trials in theatre are safe but use of ventouse was associated with a higher rate of failure.

Rising trends in the incidence of shoulder dystocia and development of a novel shoulder dystocia risk score tool: a nationwide population-based study of 800 484 Finnish deliveries

INTRODUCTION

Shoulder dystocia has remained an unpredictable and feared emergency in obstetrics. Some risk factors have been identified but nevertheless there is a lack of risk evaluation tools in clinical practice. The aim of this study was to evaluate the incidence and risk factors of shoulder dystocia in the Finnish population and to develop a shoulder dystocia risk score tool.

MATERIAL AND METHODS

This retrospective, population-based study included all deliveries in Finland between 2004 and 2017 (n = 800 484). The annual numbers of shoulder dystocia diagnoses were gathered from nationwide Finnish Medical Birth Register and Hospital Discharge Register. The incidence of shoulder dystocia was calculated in subgroups according to the mode of delivery, maternal diabetes status, body mass index (BMI), age, parity and gestational age. Based on these numbers, a shoulder dystocia risk score tool was created.

RESULTS

The overall incidence of shoulder dystocia was 0.18%. It increased significantly during the study period from 0.10% to 0.32% (P < .001). More specifically, the incidence increased significantly in all analyzed subgroups except for women with BMI <18.5 or age <20 years. To evaluate the importance of risk factors, practical and simple shoulder dystocia risk score tool was created. Instrumental vaginal delivery, maternal diabetes of any kind, BMI ≥25, age ≥40 years and gestational age ≥41 weeks were associated with higher shoulder dystocia risk compared with non-diabetic, non-obese and younger women with spontaneous deliveries before 41 weeks of gestation. In our risk score tool, cases with shoulder dystocia had a significantly higher number of risk points than those without it (15.2 vs 10.4, P < .001). The risk was significantly high when the scores were ≥18 points (relative risk 9.54, 95% confidence interval 8.61-10.57).

CONCLUSIONS

The incidence of shoulder dystocia in Finland increased during the study period but it is still low compared with previous studies from other countries. In clinical daily practice, the new shoulder dystocia risk score tool helps to evaluate the individual risk profile of the parturient. According to this risk score tool, the highest risk was found with the combination of instrumental vaginal delivery, maternal diabetes, BMI ≥25, age ≥40 years and gestational age ≥41 weeks.

Kielland's rotational forceps delivery: A comparison of maternal and neonatal outcomes with rotational ventouse or second stage caesarean section deliveries

OBJECTIVES

The objective of our study was to derive accurate estimates of risks of maternal and neonatal complications associated with Kielland's rotational forceps delivery (KRFD) compared to rotational ventouse delivery (RVD) or 2nd stage caesarean section (CS).

METHODS

This was a retrospective cohort study undertaken at a large tertiary maternity and neonatal unit in the United Kingdom between January 2010 and June 2018. Pregnancies with fetal demise, major fetal defects, those lost to follow-up, those delivering by elective or emergency CS in the first stage of labour and non-rotational instrumental deliveries were excluded. The study population included singleton pregnancies delivering by Kielland's forceps, rotational ventouse, 2nd stage CS or spontaneous unassisted cephalic vaginal delivery; the latter forming the control group. The maternal outcomes examined included post-partum haemorrhage (PPH) and obstetric anal sphincter injury (OASIS). The neonatal outcomes included admission to neonatal intensive care unit (NICU), 5-minute Apgar scores <7, hypoxic ischaemic encephalopathy (HIE), jaundice, shoulder dystocia and birth trauma. Absolute risks with 95 % confidence intervals (CI) were calculated in the study groups. Univariate and multivariate logistic regression analysis was carried out to estimate crude and adjusted odds ratio (OR) with 95 % CI.

RESULTS

The study population of 23,786 pregnancies included: 491 (2.1 %) requiring KRFD, 344 (1.4 %) requiring RVD, 840 (3.5 %) that had a 2nd stage CS and 22,111 (93.0 %) spontaneous cephalic vaginal deliveries. With regard to maternal adverse outcomes, in pregnancies that had a KRFD compared to RVD, there was no significant difference in the incidence of OASIS (p = 0.599) or PPH (p = 0.982). In contrast, the risk of PPH was significantly higher in those delivering by a 2nd stage CS compared to KRFD (27.5 % vs. 12.4 %; p < 0.0001). With regard to neonatal adverse outcomes, in those delivering by KRFD compared to RVD and 2nd stage CS, there was no significant difference in the incidence of admission to NICU (p = 0.912; p = 0.746, respectively), 5-minute Apgar score<7 (p = 0.335; p = 0.150, respectively), jaundice (p = 0.810; p = 0.332, respectively), mild shoulder dystocia (p = 0.077), severe shoulder dystocia (p = 0.603) or birth trauma (p = 0.265; p = 0.323, respectively). The risk of maternal composite adverse outcome was highest after 2nd stage CS (OR 7.68; 95 %CI: 6.52-9.04) and lowest after KRFD (OR 3.82; 95 %CI: 2.98-4.91). The risk of composite neonatal adverse outcome was higher in those delivering by RVD (OR 2.87; 95 %CI: 2.10-3.91), compared to KRFD (OR 2.23; 95 %CI: 1.67-2.97) or 2nd stage CS (OR 2.02; 95 %CI: 1.60-2.54).

CONCLUSION

Our study demonstrates that KRFD is a safer management option when compared to RVD or 2nd stage CS for the management of persistent fetal malposition in labour.

Babies in occiput posterior position are significantly more likely to require an emergency cesarean birth compared with babies in occiput transverse position in the second stage of labor: A prospective observational study

Introduction

Malposition complicates 2‐13% of births at delivery, leading to increased obstetric interventions (cesarean section and instrumental delivery) and higher rates of adverse fetal and maternal outcomes. Limited data are available regarding the likely rates of obstetric intervention and subsequent neonatal and maternal outcomes of births with babies in persistent occiput posterior position vs those in persistent occiput transverse position. The UK Audit and Research trainee Collaborative in Obstetrics and Gynecology (UK‐ARCOG) network set out to collect data prospectively at delivery on final mode of delivery and immediate outcomes.

Material and methods

The UK‐ARCOG network collected data on all births with malposition of the fetal head complicating the second stage of labor (n = 838) (occiput posterior/occiput transverse) requiring rotational vaginal operative birth or emergency cesarean to expedite delivery across 66 participating UK National Health Service maternity units over a 1‐month period. The outcomes considered were the need for emergency cesarean section without a trial of instrumental delivery, success of the first method of delivery employed in achieving a vaginal delivery and neonatal/maternal outcomes.

Results

Obstetricians regarded assistance with an operative vaginal delivery method to be unsafe in 15% of babies in occiput posterior position and 6.1% of babies in occiput transverse position, and they were delivered by primary emergency cesarean section. When vaginal delivery was deemed safe (defined as attempted assisted vaginal rotational delivery), the first instrument attempted was successful in 74.4% of occiput posterior babies and 79.3% of occiput transverse babies.

Conclusions

Our data facilitates decision making by obstetricians to increase safety of assisted rotational operative delivery of a malpositioned baby at initial assessment and in counseling women. Until data from a well‐designed randomized controlled trial of instrumental delivery vs emergency cesarean section are available, this manuscript provides contemporaneous national data from a high resource setting within a structured training program, to assist the selection of an appropriate instrument/method for the delivery of a malpositioned baby.

[Pathophysiology, diagnosis and management of occiput posterior presentation during labor]

Persistant occiput posterior (OP) positions are the commonest malpresentations of the fetal head during labor and their diagnosis remains challenging. They are associated to prolonged second stage of labor, prolonged expulsive efforts, labor augmentation, cesarean sections and instrumental deliveries. On the maternal side, severe perineal tears, post-partum hemorrhage or chorioamnionitis are more frequent. Currently, prevention of persistent OP positions is based on the maintain of precise maternal positions. Several positions have been evaluated but only lateral position on the same side of the fetal spine has proved its effectiveness. Fetal head rotation can also be achieved with extraction instruments though none has ever been evaluated by a randomized controlled trial. Obstetrical forceps seem more efficient than vacuum but are associated with severe perineal tears. Evaluation of rotation with Thierry's spatulas is scarce. Last, manual rotation is of routine use in many wards. This management is associated with a twofold reduction of operative delivery rate and rare adverse outcomes but has never been evaluated through randomized control trial.

The role of manual rotation in avoiding and managing OVD

Manual rotation (MR) is the most common technique used by accoucheurs who wish to correct malposition of the foetal head to either avoid or facilitate an operative vaginal delivery (OVD). MR can be performed using either a whole-hand or a digital approach. MR should be formally taught and trainees should be assessed for competence, and later, performance should ideally be tracked with statistical control charts. There is paucity of robust evidence evaluating MR relative to the other methods of rotational OVD: rotational forceps (RF) and rotational ventouse (RV). Furthermore, there is little evidence concerning long-term maternal outcomes of rotational OVD. A prospective randomised trial of MR versus either RF or RV is clearly needed, along with a core outcome set for OVD to facilitate comprehensive evaluation programmes that focus on aspects pertaining to women.

Operative vaginal delivery in case of persistent occiput posterior position after manual rotation failure: a 6-month follow-up on pelvic floor function

PURPOSE

To compare the short- and long-term perineal consequences (at 6 months postpartum) and short-term neonatal consequences of instrumental rotation (IR) to those induced by assisted delivery (AD) in the occiput posterior (OP) position, in case of manual rotation failure.

METHODS

A prospective observational cohort study; tertiary referral hospital including all women presenting with persistent OP position who delivered vaginally after manual rotation failure with attempted IR or AD in OP position from September 2015 to October 2016. Maternal and neonatal outcomes of all attempted IR deliveries were compared with OP operative vaginal deliveries. Main outcomes measured were pelvic floor function at 6 months postpartum including Wexner score for anal incontinence and ICIQ-FLUTS for urinary symptoms. Perineal morbidity comprised severe perineal tears, corresponding to third and fourth degree lacerations. Fetal morbidity parameters comprised low neonatal Apgar scores, acidaemia, major and minor fetal injuries and neonatal intensive care unit admissions.

RESULTS

Among 5265 women, 495 presented with persistent OP positions (9.4%) and 111 delivered after manual rotation failure followed by AD delivery: 58 in the IR group and 53 in the AD in OP group. The incidence of anal sphincter injuries was significantly reduced after IR attempt (1.7% vs. 24.5%; p < 0.001) without increasing neonatal morbidity. At 6 months postpartum, AD in OP position was associated with higher rate of anal incontinence (30% vs. 5.5%, p = 0.001) and with more urinary symptoms, dyspareunia and perineal pain.

CONCLUSIONS

OP operative deliveries are associated with significant perineal morbidity and pelvic floor dysfunction at 6 months postpartum.

Incidence and risk factors of severe lacerations during forceps delivery in a single teaching hospital where simulation training is held annually

AIM

This study was conducted to evaluate the incidence of severe lacerations during forceps delivery and the risk factors associated with such delivery in a hospital where simulation training is held annually.

METHODS

The medical records of 857 women who underwent forceps delivery at term with singleton cephalic presentation from 2010 to 2015 were reviewed. The relationship between clinical characteristics and birth canal trauma was analyzed. Birth canal trauma included third and fourth degree perineal lacerations. Univariable and multivariable models of logistic regression were employed to estimate the raw odds ratio and were adjusted for cofactors with 95% confidence intervals. Statistical significance was defined as P < 0.05.

RESULTS

The incidence of severe lacerations was 10.1%. Birth weight, fetal head station, the rate of malrotation and the number of extractions were higher in women with severe lacerations (P < 0.01), whereas the use of obstetric anesthesia was lower in women with such lacerations (P < 0.01). Neither the indication for forceps delivery nor the qualifications of the operator had any influence on the incidence of severe lacerations.

CONCLUSION

The incidence of severe lacerations was relatively low. Risk factors for severe lacerations with forceps delivery were identified as birth weight, fetal head station, malrotation and the number of extractions. Obstetric anesthesia may protect against severe lacerations.

Neonatal and maternal outcomes of successful manual rotation to correct malposition of the fetal head; A retrospective and prospective observational study

Objective

To evaluate the neonatal and maternal outcomes associated with successful operative vaginal births assisted by manual rotation.

Design

Prospective and retrospective observational study.

Setting

Delivery suite in a tertiary referral teaching hospital in England.

Population

A cohort of 2,426 consecutive operative births, in the second stage of labour, complicated with malposition of the fetal head during 2006–2013.

Methods

Outcomes of all births successfully assisted by manual rotation followed by direct traction instruments were compared with other methods of operative birth for fetal malposition in the second stage of labour (rotational ventouse, Kielland forceps and caesarean section).

Main outcome measures

Associated neonatal outcomes (admission to the special care baby unit, low cord pH, low Apgar and shoulder dystocia) and maternal outcomes (massive obstetric haemorrhage (blood loss of >1500ml) and obstetric anal sphincter injury).

Results

Births successfully assisted with manual rotation followed by direct traction instruments, resulted in 10% (36/346) of the babies being admitted to the Special Care Baby Unit, 4.9% (17/349) shoulder dystocia, 2% (7/349) massive obstetric haemorrhage and 1.7% (6/349) obstetric anal sphincter injury, similar to other methods of rotational births.

Conclusions

Adverse neonatal and maternal outcomes associated with successful manual rotations followed by direct traction instruments were comparable to traditional methods of operative births. There is an urgent need to standardise the practice (guidance, training) and documentation of manual rotation followed by direct traction instrumental deliveries that will enable assessment of its efficacy and the absolute safety in achieving a vaginal birth.

Lateral asymmetric decubitus position for the rotation of occipito-posterior positions: multicenter randomized controlled trial EVADELA

BACKGROUND

Fetal occiput posterior positions are associated with poorer maternal outcomes than occiput anterior positions. Although methods that include instrumental and manual rotation can be used at the end of labor to promote the rotation of the fetal head, various maternal postures may also be performed from the beginning of labor in occiput posterior position. Such postures might facilitate flexion of the fetal head and favor its rotation into an occiput anterior position.

OBJECTIVE

The purpose of this study was to determine whether a lateral asymmetric decubitus posture facilitates the rotation of fetal occiput posterior into occiput anterior positions.

STUDY DESIGN

Evaluation of Decubitus Lateral Asymmetric posture was a multicenter randomized controlled trial that included 322 women from May 2013 through December 2014. Study participants were women who labored with ruptured membranes and a term fetus that was confirmed by ultrasound imaging to be in cephalic posterior position. Women who were assigned to the intervention group were asked to lie in a lateral asymmetric decubitus posture on the side opposite that of the fetal spine during the first hour and encouraged to maintain this position for as long as possible during the first stage of labor. In the control group, women adopted a dorsal recumbent posture during the first hour after random assignment. The primary outcome was occiput anterior position at 1 hour after random assignment. Secondary outcomes were occiput anterior position at complete dilation, mode of delivery, speed of dilation during the active first stage, maternal pain, and women's satisfaction.

RESULTS

One hundred sixty women were assigned to the intervention group, and 162 women were assigned to the control group. One hour after random assignment, the rates of occiput anterior position did not differ between the intervention and control groups (21.9% vs 21.6%, respectively; P=.887). Occiput anterior rates did not differ between groups at complete dilation (43.7% vs 43.2%, respectively; P=.565) or at birth (83.1% vs 86.4%, respectively; P=.436). Finally, the groups did not differ significantly for cesarean delivery rates (18.1% among women in lateral asymmetric decubitus and 14.2% among control subjects (P=0.608) or for speed of cervical dilation during the active first stage of labor (P=.684), pain assessment (P=.705), or women's satisfaction (P=.326). No maternal or neonatal adverse effect that was associated with either posture was observed.

CONCLUSION

Lateral asymmetric decubitus position on the side opposite that of the fetal spine did not facilitate rotation of fetal head. Nevertheless, other maternal positions may be effective in promoting fetal head rotation. Further research is needed; posturing during labor, nonetheless, should remain a woman's active choice.

Obstetric management in vacuum-extraction deliveries

OBJECTIVE

The aim of this observational study was to describe the obstetric management in vacuum extraction (VE) deliveries and to compare these findings to instructions in clinical guidelines on VE.

METHODS

In 2013, detailed data on management of 600 VE cases were consecutively collected from six different delivery units in Sweden. Each unit also contributed their own clinical VE guideline.

RESULTS

In total, 93% of the VEs ended with a vaginal delivery while 7% failed and were converted to an emergency cesarean section. In 2.3% extraction time exceeded 20 minutes, and in 6% more than six pulls were used to deliver the fetus. Cup detachment occurred in 14.6%, and fundal pressure was used in 11% of the deliveries. In 2.3%, fetal station was assessed as above the level of the maternal ischial spines. The clinical guidelines on VE varied in scope and content between units, and were often incomplete according to best practice.

CONCLUSION

The vast majority of the VEs were conducted in accordance with safety recommendations. However, in a few extractions, safety rules were disregarded and more than six pulls or an extraction time of more than 20 minutes were used to complete the delivery.

Maternal and Neonatal Morbidity After Attempted Operative Vaginal Delivery According to Fetal Head Station

OBJECTIVE

To compare severe short-term maternal and neonatal morbidity associated with midpelvic and low pelvic attempted operative vaginal delivery.

METHODS

Prospective study of 2,138 women with live singleton term fetuses in vertex presentation who underwent an attempted operative vaginal delivery in a tertiary care university hospital. We used multivariate logistic regression and propensity score methods to compare outcomes associated with midpelvic and low pelvic delivery. Severe maternal morbidity was defined as third- or fourth-degree perineal laceration, perineal hematoma, cervical laceration, extended uterine incision for cesarean delivery, postpartum hemorrhage greater than 1,500 mL, surgical hemostatic procedures, uterine artery embolization, blood transfusion, infection, thromboembolic events, admission to the intensive care unit, and maternal death; severe neonatal morbidity was defined as 5-minute Apgar score less than 7, umbilical artery pH less than 7.00, need for resuscitation or intubation, neonatal trauma, intraventricular hemorrhage greater than grade 2, neonatal intensive care unit admission for more than 24 hours, convulsions, sepsis, and neonatal death.

RESULTS

From December 2008 through October 2013 there were 2,138 attempted operative vaginal deliveries; 18.3% (n=391) were midpelvic, 72.5% (n=1,550) low, and 9.2% (n=197) outlet. Severe maternal morbidity occurred in 10.2% (n=40) of midpelvic, 7.8% (n=121) of low, and 6.6% (n=13) of outlet attempts (P=.21); and severe neonatal morbidity in 15.1% (n=59), 10.2% (n=158), and 10.7% (n=21) (P=.02), respectively. Multivariable logistic regression analysis found no significant difference between midpelvic and low attempted operative vaginal delivery for either composite severe maternal (adjusted odds ratio [OR] 1.01, 95% confidence interval [CI] 0.66-1.55) or neonatal morbidity (adjusted OR 1.25, 95% CI 0.84-1.86). Similarly, propensity score matching found no significant difference between midpelvic and low operative vaginal delivery for either severe maternal (adjusted OR 0.69, 95% CI 0.39-1.22) or neonatal morbidity (adjusted OR 0.88, 95% CI 0.53-1.45).

CONCLUSION

In singleton term pregnancies, midpelvic attempted operative vaginal delivery compared with low pelvic attempted operative vaginal delivery was not associated with an increase in severe short-term maternal or neonatal morbidity.

LEVEL OF EVIDENCE

II.

Delivery mode and pelvic organ prolapse: a retrospective observational study

OBJECTIVE

To analyse the associations between delivery mode and symptoms and signs of pelvic organ prolapse (POP) in a cohort of symptomatic women.

DESIGN

Retrospective observational study.

POPULATION

A total of 1258 consecutive women attending a tertiary urogynaecological unit for the investigation of lower urinary tract or pelvic floor disorders between January 2012 and December 2014.

METHODS

Obstetric history and clinical examination data were obtained from the unit database. Prolapse quantification on imaging was performed using stored four-dimensional translabial ultrasound volume data sets. Women were grouped into four groups according to the most traumatic delivery reported. The presence of symptoms and signs of POP were compared between delivery groups while controlling for potential confounders.

MAIN OUTCOME MEASURES

Prolapse symptoms, visual analogue score for prolapse bother, International Continence Society Prolapse Quantification System findings and ultrasound findings of anterior, central and posterior compartment descent.

RESULTS

Nulliparae showed the lowest prevalence of most measures of POP, followed by women exclusively delivered by caesarean section. Highest prevalences were consistently found in women delivered at least once by forceps, although the differences between this group and women delivered by normal vaginal delivery and/or vacuum extraction were significant in three out of eight measures only. Compared with women in the caesarean section group, the adjusted odds ratios for reporting symptoms of prolapse were 2.4 (95% CI 1.30-4.59) and 3.2 (95% CI 1.65-6.12) in the normal vaginal delivery/vacuum extraction group and forceps group, respectively.

CONCLUSIONS

There is a clear link between vaginal delivery and symptoms and signs of pelvic organ prolapse in urogynaecological patients.

TWEETABLE ABSTRACT

Compared with caesarean section a history of vaginal delivery more than doubles the risk for POP.

Learning From Experience: Qualitative Analysis to Develop a Cognitive Task List for Kielland Forceps Deliveries

OBJECTIVE

Fetal malposition is a common indication for Caesarean section in the second stage of labour. Rotational (Kielland) forceps are a valuable tool in select situations for successful vaginal delivery; however, learning opportunities are scarce. Our aim was to identify the verbal and non-verbal components of performing a safe Kielland forceps delivery through filmed demonstrations by expert practitioners on models to develop a task list for training purposes.

METHODS

Labour and delivery nurses at three university-affiliated hospitals identified clinicians whom they considered skilled in Kielland forceps deliveries. These physicians gave consent and were filmed performing Kielland forceps deliveries on a model, describing their assessment and technique and sharing clinical pearls based on their experience. Two clinicians reviewed the videos independently and recorded verbal and non-verbal components of the assessment; thematic analysis was performed and a core task list was developed. The algorithm was circulated to participants to ensure consensus.

RESULTS

Eleven clinicians were identified; eight participated. Common themes were prevention of persistent malposition where possible, a thorough assessment to determine suitability for forceps delivery, roles of the multidisciplinary team, description of the Kielland forceps and technical aspects related to their use, the importance of communication with the parents and the team (including consent, debriefing, and documentation), and "red flags" that indicate the need to stop when safety criteria cannot be met.

CONCLUSION

Development of a cognitive task list, derived from years of experience with Kielland forceps deliveries by expert clinicians, provides an inclusive algorithm that may facilitate standardized resident training to enhance education in rotational forceps deliveries.

Persistent occiput posterior

Persistent occiput posterior (OP) is associated with increased rates of maternal and newborn morbidity. Its diagnosis by physical examination is challenging but is improved with bedside ultrasonography. Occiput posterior discovered in the active phase or early second stage of labor usually resolves spontaneously. When it does not, prophylactic manual rotation may decrease persistent OP and its associated complications. When delivery is indicated for arrest of descent in the setting of persistent OP, a pragmatic approach is suggested. Suspected fetal macrosomia, a biparietal diameter above the pelvic inlet or a maternal pelvis with android features should prompt cesarean delivery. Nonrotational operative vaginal delivery is appropriate when the maternal pelvis has a narrow anterior segment but ample room posteriorly, like with anthropoid features. When all other conditions are met and the fetal head arrests in an OP position in a patient with gynecoid pelvic features and ample room anteriorly, options include cesarean delivery, nonrotational operative vaginal delivery, and rotational procedures, either manual or with the use of rotational forceps. Recent literature suggests that maternal and fetal outcomes with rotational forceps are better than those reported in older series. Although not without significant challenges, a role remains for teaching and practicing selected rotational forceps operations in contemporary obstetrics.

Kielland's forceps: does it increase the risk of anal sphincter injuries? An observational study

INTRODUCTION AND HYPOTHESIS

Rotational instrumental deliveries are thought to carry additional risks compared with non-rotational instrumental deliveries, including trauma to maternal tissues, and require specific expertise and training. We conducted a retrospective study to investigate the association between the type of forceps delivery and maternal perineal trauma, and in particular to investigate if Kielland's rotational forceps delivery increases obstetric anal sphincter injuries (OASIS).

METHODS

This is a retrospective observational study of 1,515 women who attended a tertiary maternity unit over a period of 5 years and had operative vaginal deliveries primarily or completed by forceps. Data were obtained through the hospital's maternity reporting system. The severity of maternal perineal trauma, particularly third and fourth-degree tears in relation to the type of forceps delivery was explored. Multinomial logistic regression models were used to estimate the crude and the adjusted relative risks (RR) of sustaining third-degree tears compared with other types of vaginal tears. Univariate analyses explored the crude associations between relative risks and age, ethnicity, birth weight, type of instrumental delivery and operator's experience. A multivariate multinomial logistic regression model estimated the adjusted relative risks and included all the previous variables as independent covariates.

RESULTS

Of the 1,492 women included in the study, 150 women (77 %) had sustained category 1 tears, 63 women (4 %) had sustained category 2 tears and 279 women (19 %) had sustained third-degree tears. There was no statistically significant association between the severity of maternal perineal trauma and the type of forceps delivery (failed ventouse vs Kielland's forceps RR 1.52, p = 0.159 CI 0.84-2.72, Wrigleys vs Kielland's RR 0.59, p = 0.249, CI 0.24-1.43; Andersons vs Kielland's RR 1.16, p = 0.603, CI 0.65-2.05) after adjusting for age, birth weight, BMI, ethnicity and operator experience (full list of covariates not included).

CONCLUSIONS

The incidence of third- and fourth-degree tears following rotational Kielland's forceps delivery and other non-rotational forceps deliveries is comparable.

Management of fetal malposition in the second stage of labor: a propensity score analysis

OBJECTIVE

We sought to determine the factors associated with selection of rotational instrumental vs cesarean delivery to manage persistent fetal malposition, and to assess differences in adverse neonatal and maternal outcomes following delivery by rotational instruments vs cesarean delivery.

STUDY DESIGN

We conducted a retrospective cohort study over a 5-year period in a tertiary United Kingdom obstetrics center. In all, 868 women with vertex-presenting, single, liveborn infants at term with persistent malposition in the second stage of labor were included. Propensity score stratification was used to control for selection bias: the possibility that obstetricians may systematically select more difficult cases for cesarean delivery. Linear and logistic regression models were used to compare maternal and neonatal outcomes for delivery by rotational forceps or ventouse vs cesarean delivery, adjusting for propensity scores.

RESULTS

Increased likelihood of rotational instrumental delivery was associated with lower maternal age (odds ratio [OR], 0.95; P < .01), lower body mass index (OR, 0.94; P < .001), lower birthweight (OR, 0.95; P < .01), no evidence of fetal compromise at the time of delivery (OR, 0.31; P < .001), delivery during the daytime (OR, 1.45; P < .05), and delivery by a more experienced obstetrician (OR, 7.21; P < .001). Following propensity score stratification, there was no difference by delivery method in the rates of delayed neonatal respiration, reported critical incidents, or low fetal arterial pH. Maternal blood loss was higher in the cesarean group (295.8 ± 48 mL, P < .001).

CONCLUSION

Rotational instrumental delivery is often regarded as unsafe. However, we find that neonatal outcomes are no worse once selection bias is accounted for, and that the likelihood of severe obstetric hemorrhage is reduced. More widespread training of obstetricians in rotational instrumental delivery should be considered, particularly in light of rising cesarean delivery rates.

A prospective cohort study of the morbidity associated with operative vaginal deliveries performed by day and at night

OBJECTIVE

To evaluate maternal and neonatal outcomes associated with operative vaginal deliveries (OVDs) performed by day and at night.

DESIGN

Prospective cohort study.

SETTING

Urban maternity unit in Ireland with off-site consultant staff at night.

POPULATION

All nulliparous women requiring an OVD with a term singleton fetus in a cephalic presentation from February to November 2013.

METHODS

Delivery outcomes were compared for women who delivered by day (08:00-19:59) or at night (20:00-07:59).

MAIN OUTCOME MEASURES

The main outcomes included postpartum haemorrhage (PPH), anal sphincter tear and neonatal unit admission. Procedural factors included operator grade, sequential use of instruments and caesarean section.

RESULTS

Of the 597 women who required an OVD, 296 (50%) delivered at night. Choice of instrument, place of delivery, sequential use of instruments and caesarean section did not differ significantly in relation to time of birth. Mid-grade operators performed less OVDs by day than at night, OR 0.60 (95% CI 0.43 to 0.83), and a consultant supervisor was more frequently present by day, OR 2.26 (95% CI 1.05 to 4.83). Shoulder dystocia occurred more commonly by day, OR 2.57 (95% CI 1.05 to 6.28). The incidence of PPH, anal sphincter tears, neonatal unit admission, fetal acidosis and neonatal trauma was similar by day and at night. The mean decision to delivery intervals were 12.0 and 12.6 min, respectively.

CONCLUSIONS

There was no evidence of an association between time of OVD and adverse perinatal outcomes despite off-site consultant obstetric support at night.