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.