A prospective randomized study comparing maternal and fetal effects of forceps delivery and vacuum extraction

"Assisted vaginal birth using the Paily obstetric forceps vs Ventouse - A randomized clinical trial"

OBJECTIVE

Instruments used in assisted vaginal birth have seen little innovation for decades. Due to the risk of trauma and technical difficulty incurred during forceps delivery, instrumental deliveries are on a decline, and the global rate of primary cesarean birth is rising. The novel Paily Obstetric Forceps (POF) features a compact, lighter design with thinner blades, designed to increase operator comfort and minimize maternal and neonatal injuries. We aim to determine the feasibility and safety of POF in achieving vaginal birth compared to a ventouse device with a 50 mm silastic cup.

STUDY DESIGN

We conducted a single-blinded, parallel arm, randomized clinical trial of the novel POF vs a ventouse device, in patients undergoing indicated assisted vaginal birth, at a tertiary care obstetric unit. We randomized 100 patients to be allocated on a 1:1 ratio to both intervention arms. Primary outcome was the proportion of successful instrumental deliveries. Secondary outcomes were the number of pulls required during traction and any maternal or neonatal adverse events.

RESULTS

The POF was significantly more successful in achieving vaginal birth than the ventouse device (n = 50/50, 100 % vs n = 42/50, 84 %, p = 0.006). Operators reported requiring significantly fewer pulls during POF traction than ventouse. POF demonstrated a higher risk for maternal trauma (RR = 3.2, 95 % CI = 1.5 to 6.9, NNH = 2.7) but a lower risk for neonatal injury (RR = 0.6, 95 % CI = 0.3 to 1, NNH = 5.7). Maternal and neonatal recovery durations were comparable. There were no incidences of maternal or neonatal mortality.

CONCLUSION

The POF can be used in indicated assisted vaginal birth with superior success rates and better neonatal outcomes than ventouse. Other obstetric forceps must be standardized to conduct larger superiority trials of forceps designs.

Instruments for assisted vaginal birth

BACKGROUND

Assisted vaginal births are carried out to expedite birth for the benefit of mothers and babies but are sometimes associated with significant morbidity for both. Various instruments are available, broadly divided into forceps and vacuum cups, and choice may be influenced by clinical circumstances, operator preference, experience and availability.  OBJECTIVES: To evaluate the different instruments in terms of success in achieving a vaginal birth, and the risk of morbidity for mother and baby.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (14 May 2021), and reference lists of retrieved studies.

SELECTION CRITERIA

We selected randomised controlled trials of assisted vaginal birth using different instruments. The review did not include quasi-randomised trials, cluster-randomised trials or cross-over designs. The review included trials for which abstracts alone were available as long as there was sufficient information to assess eligibility.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. We used the GRADE approach to assess the certainty of evidence.  The main outcomes assessed included failed delivery with allocated instrument, any maternal trauma, third- and fourth-degree tears, postpartum haemorrhage, any neonatal trauma, low Apgar and low umbilical artery pH.  MAIN RESULTS: We included 31 studies involving a total of 5754 women.  Risk of bias criteria were largely assessed as 'unclear', due to a lack of detail in trial reports. Blinding would have been challenging for all trials due to their inability to conceal the type of instrument used from either the woman or the operator, which is reflected in the risk of bias assessment. Any type of forceps versus any type of vacuum cup (12 studies, 3129 women) Forceps may be less likely to fail in achieving vaginal birth: risk ratio (RR) 0.58, 95% confidence interval (CI) 0.39 to 0.88; 11 studies, 3080 women; low certainty. 'Any maternal trauma' may be slightly more likely with forceps: odds ratio (OR) 1.53, 95% CI 0.98 to 2.40; 5 studies, 1356 women; low certainty; and third- or fourth-degree tears may also be more likely with forceps: RR 1.83, 95% CI 1.32 to 2.55; 9 studies, 2493 women; low certainty. There is no evidence of a difference in the incidence of postpartum haemorrhage (PPH) between the two groups: RR 1.71, 95% CI 0.59 to 4.95; 2 studies, 523 women; low certainty, because the evidence is very imprecise due to a very wide CI.  More women in the forceps group reported requiring pain relief. There is probably no evidence of difference in rates of low Apgar: RR 0.83, 95% CI 0.46 to 1.51; 7 studies, 1644 women; moderate certainty; or low umbilical artery pH in the forceps group compared to any vacuum: RR 1.33, 95% CI 0.91 to 1.93; 2 studies, 789 women; low certainty; both of these outcomes are imprecise and have wide CIs that include both benefit and harm. There were also lower rates of fetal trauma with 'any forceps' (cephalhematoma, retinal haemorrhage and jaundice). The composite outcome of 'any neonatal trauma' was not reported. Low-cavity forceps versus any vacuum cup (2 studies, 218 women) We included two small studies with 218 participants in this comparison, but we judged most of the evidence as very low certainty, hence it was not feasible to make judgements on the difference in the rates of failed delivery, any maternal trauma or third- and fourth- degree tears. PPH and low umbilical artery pH were not reported. Soft vacuum cup versus any rigid cup (9 studies, 1148 women) Failed delivery may be more likely in the soft vacuum cup group: RR 1.62, 95% CI 1.21 to 2.17; 9 studies, 1148 women; low certainty. There may be no difference in the rates of 'any maternal trauma': OR 0.63, 95% CI 0.24 to 1.67; 2 studies, 348 women; low certainty, but the confidence interval is wide, indicating possible benefit or harm. There may be no difference in the rates of third- or fourth-degree tears: RR 0.93, 95% CI 0.35 to 2.44; 4 studies, 619 women; low certainty. There is probably no difference in the rates of PPH: RR 0.89, 95% CI 0.49 to 1.61; 5 studies, 737 women; moderate certainty between the soft and rigid cup groups.   There may be little or no difference in the incidence of low Apgar scores: RR 0.82, 95% CI 0.49 to 1.37; 9 studies, 1148; low certainty; or low umbilical artery pH: RR 0.80, 95% CI 0.47 to 1.36; 1 study, 100 women; low certainty. Handheld vacuum versus any vacuum cup (4 studies, 968 women) There may be no difference in the rates of failures with allocated instrument: RR 1.35, 95% CI 0.81 to 2.25; 4 studies, 962 women; low certainty, any maternal trauma: OR 1.16, 95% CI 0.71 to 1.88; 2 studies; 394 women; low certainty, PPH: RR 0.31, 95% CI 0.03 to 2.92; 1 study, 164 women; low certainty, low umbilical artery pH: RR 1.06, 95% CI 0.71 to 1.59; 1 study, 164 women; low certainty, or low Apgar scores: RR 1.25, 95% CI 0.34 to 4.61; 3 studies, 784 women; low certainty) between the two groups. There is probably no difference in the rates of third- or fourth-degree tears between the 'handheld vacuum' and 'any vacuum cup' groups: RR 1.15, 95% CI 0.62 to 2.12; 4 studies, 962 women; moderate certainty.

AUTHORS' CONCLUSIONS

This review provides low-certainty evidence that forceps may be more likely to achieve vaginal birth and have lower rates of fetal trauma, but at a greater risk of perineal trauma and higher pain relief requirements compared with vacuum cups. There was low-certainty evidence that rigid vacuum cups may be more likely to achieve a vaginal birth than soft cups but with more fetal trauma, whilst handheld vacuum cups had similar success rates compared to other cups. There was no evidence of a difference in the rates of third- or fourth-degree tears or postpartum haemorrhages between types of cups, but wide confidence intervals around the estimates indicate further research is needed in this area.

Effect of perineum protection cooperated by two operators in the forceps-assisted vaginal delivery: a case-control study

Objective: To investigate the effect of unique skill of perineum protection in forceps delivery on the maternal and neonatal morbidity.Methods: A case-control study was conducted. Singleton pregnancies with forceps-assisted and normal vaginal deliveries were recruited. The maternal and neonatal complications were compared between forceps and normal deliveries.Results: Five hundred forty participants were included. The prevalence of maternal anal sphincter injury, postpartum hemorrhage, vaginal hematoma, cervical laceration, perineal wound infection, perineal wound dehiscence, dyspareunia, urinary incontinence, and anal incontinence were not significantly different between forceps and normal deliveries (p > .05). However, the rate of neonatal facial injury was higher in the forceps group (2.9% versus 0, p = .004).Conclusions: Cooperation according to the tension of perineum and labor process between obstetrician and midwife is important for perineum protection. Forceps-assisted delivery concentrating on perineum protection is an effective alternative in decreasing maternal morbidity.

Endothelial Cell Loss in Obstetric Forceps-Related Corneal Injury: A Longitudinal Specular Microscopic Study

PURPOSE

To assess the impact of ocular trauma associated with obstetric forceps delivery on the corneal endothelium in children.

METHODS

Five patients who attended the Hospital for Sick Children, Toronto, between 2013 and 2016 with a diagnosis of unilateral obstetrical forceps-related corneal injury were included. Clinical presentation, best-corrected visual acuity, corneal endothelial cell density (ECD, cells/mm), and measures of cellular morphology were obtained.

RESULTS

The mean follow-up duration was 30 ± 10 months. Mean ECD in the affected eye at initial assessment was significantly lower than that of the fellow eye (2576 ± 733 vs. 3481 ± 288 cells/mm, P = 0.02). At final follow-up, mean ECD was 3293 ± 175 and 1907 ± 524 cells/mm in the normal and affected eyes, respectively (P = 0.004). The mean annual rate of the ECD decrease was higher in the affected eyes than in the normal eyes (9.1% ± 4.2% vs. 2.0% ± 2.5%), although this difference was not statistically significant (P = 0.06).

CONCLUSIONS

In children with forceps-related corneal injury, lower ECD with a higher annual decrease can be assessed with specular microscopy for risk stratification and parental counseling purposes.

Anal sphincter defects and fecal incontinence 15-24 years after first delivery: a cross-sectional study

OBJECTIVES

To establish the prevalence of external (EAS) and internal (IAS) anal sphincter defects present 15-24 years after childbirth according to mode of delivery, and their association with development of fecal incontinence (FI). The study additionally aimed to compare the proportion of women with obstetric anal sphincter injuries (OASIS) reported at delivery with the proportion of women with sphincter defect detected on ultrasound 15-24 years later.

METHODS

This was a cross-sectional study including 563 women who delivered their first child between 1990 and 1997. Women responded to a validated questionnaire (Pelvic Floor Distress Inventory) in 2013-2014, from which the proportion of women with FI was recorded. Information about OASIS was obtained from the National Birth Registry. Study participants underwent four-dimensional transperineal ultrasound examination. Defect of EAS or IAS of ≥ 30° in at least four of six slices on tomographic ultrasound was considered a significant defect and was recorded. Four study groups were defined based on mode of delivery of the first child. Women who had delivered only by Cesarean section (CS) constituted the CS group. Women in the normal vaginal delivery (NVD) group had NVD of their first child and subsequent deliveries could be NVD or CS. The forceps delivery (FD) group included women who had FD, NVD or CS after FD of their first born. The vacuum delivery (VD) group included women who had VD, NVD or CS after VD of their first born. Multiple logistic regression was used to calculate adjusted odds ratios (aORs) for comparison of prevalence of an EAS defect following different modes of delivery and to test its association with FI. Fisher's exact test was used to calculate crude odds ratios (ORs) for IAS defects.

RESULTS

Defects of EAS and IAS were found after NVD (n = 201) in 10% and 1% of cases, respectively, after FD (n = 144) in 32% and 7% of cases and after VD (n = 120) in 15% and 4% of cases. No defects were found after CS (n = 98). FD was associated with increased risk of EAS defect compared with NVD (aOR = 3.6; 95% CI, 2.0-6.6) and VD (aOR = 3.0; 95% CI, 1.6-5.6) and with increased risk of IAS defect compared with NVD (OR = 7.4; 95% CI, 1.5-70.5). The difference between VD and NVD was not significant for EAS or IAS. FI was reported in 18% of women with an EAS defect, in 29% with an IAS defect and in 8% without a sphincter defect. EAS and IAS defects were associated with increased risk of FI (aOR = 2.5 (95% CI, 1.3-4.9) and OR = 4.2 (95% CI, 1.1-13.5), respectively). Of the ultrasonographic sphincter defects, 80% were not reported as OASIS at first or subsequent deliveries.

CONCLUSIONS

Anal sphincter defects visualized on transperineal ultrasound 15-24 years after first delivery were associated with FD and development of FI. Ultrasound revealed a high proportion of sphincter defects that were not recorded as OASIS at delivery. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Obstetric anal sphincter injury and incontinence 15-23 years after vaginal delivery

INTRODUCTION

The primary aim was to study prevalence of obstetric anal sphincter injuries (OASIS) after normal vaginal deliveries (NVD) and operative vaginal deliveries (OVD) with a subgroup analysis of forceps (FD) vs. vacuum deliveries (VD). The secondary aim was to study the association between OASIS and anal incontinence 15-23 years later.

MATERIAL AND METHODS

This was a cross-sectional study including 8137 primiparous women in Trondheim, Norway, from 1990 to 1997. The outcome measure was the adjusted odds ratio (aOR) for OASIS between delivery groups. A total of 1122 women responded to a postal questionnaire containing the Colorectal-Anal Distress Inventory (CRADI) in 2013. The aOR for anal incontinence and the difference in CRADI score between women with and without OASIS were calculated.

RESULTS

OASIS prevalence was 2% for NVD and 10% for OVD (10% FD, 9% VD). aOR for OASIS was 5.01 (95%CI 3.85-6.51) comparing OVD with NVD. There was no difference between FD and VD (aOR 1.15, 95% CI 0.79-1.67). FD was associated with higher risk of fourth degree perineal tear than VD (aOR 5.08, 95% CI 1.47-17.49). OASIS was associated with increased risk of leakage of well-formed (aOR 8.61, 95% CI 3.08-24.12) and loose stool (aOR 2.75, 95% CI 1.43-5.27) and higher CRADI score (Mann-Whitney U-test, p = 0.01).

CONCLUSIONS

OVD was associated with increased risk of OASIS. FD was associated with higher risk of fourth degree perineal tear compared with VD. OASIS was associated with increased risk of anal incontinence and higher CRADI score 15-23 years later.

Intrapartum care and substandard care: juridical recommendations to reduce the risk of liability

PURPOSE

To develop juridical recommendations to reduce medical liability of the obstetrician, providing intrapartum care.

METHODS

107 legal proceedings of the past 40 years from Belgium, France and the Netherlands, involving medical negligence of the obstetrician during intrapartum care, were analyzed in depth. The legal databases used were Jura and Judit (Belgium), Legifrance, Juricaf and Dalloz (France) and Recht, Rechtspraak (the Netherlands). A minority of the cases were retrieved through contacts with insurance companies (Belgium only) and courts.

RESULTS

The judicial assessment of negligence is focused on four domains of expertise of the obstetrician: 36 % (38/107) recognizing a specific pathology, 33 % (35/107) interpreting fetal monitoring, 19 % (21/107) performing a forceps/vacuum-assisted delivery and 12 % (13/107) managing shoulder dystocia. The highest liability rate of 86 % (30/35) was reflected in the category of interpreting fetal monitoring.

CONCLUSION

To reduce the liability rate of 66 %, several policy recommendations can be made. Respond to the first symptoms of obstetric complications (particularly placental abruption and uterine rupture). Secondly, respond to disturbing messages of the midwife concerning fetal distress and evaluate every deviation in fetal heart rate monitoring. Education concerning the interpretation of fetal monitoring is a must for every midwife and obstetrician. Use proper methods to monitor the heart rate to optimize the quality of the signal. The third recommendation is to be cautious about opting for a forceps/vacuum-assisted delivery, consider all circumstances. Consider the risk of failed instrumental delivery. And finally in relation to shoulder dystocia, recognize the risk factors by ordering further examinations to purchase a diagnosis.

Análise da hemorragia no parto vaginal pelos índices de eritrócitos e hematócrito

Objetivo: Analisar a hemorragia no parto vaginal através dos índices de eritrócitos e hematócrito. Métodos: Estudo transversal realizado em 328 partos vaginais divididos em: espontâneo, com e sem episiotomia, e parto fórceps. A amostragem foi aleatória estratificada por tipo de parto vaginal. Os dados foram coletados na internação para o parto, na alta hospitalar e no retorno puerperal. Resultados: Foram estudados 122 (37,2%) partos sem episiotomia, 147 (44,8%) com episiotomia e 59 (18,0%) com uso de fórceps e episiotomia. O valor individual de hemoglobina, entre a internação para o parto e a alta hospitalar variou de -5,9 g/dl a 0,7 g/dl.A redução da hemoglobina foi significativamente maior no parto fórceps comparado aos partos espontâneos, com e sem episiotomia, p=0,0133 e p<0,0001, respectivamente. No parto fórceps a hemorragia é maior quando comparada aos outros tipos de parto. Conclusão: A análise da hemorragia no parto vaginal através dos índices de eritrócitos e hematócrito evidenciou que há variação nos três tipos de parto vaginal estudados, sendo a hemorragia maior no parto fórceps e menor no parto vaginal espontâneo. No puerpério, nos casos de partos fórceps estes índices mantiveram-se inferiores aos da internação.