Perinatal and maternal morbidity and mortality among term singletons following midcavity operative vaginal delivery versus caesarean delivery.

OBJECTIVE

To quantify severe perinatal and maternal morbidity/mortality associated with midcavity operative vaginal delivery compared with caesarean delivery.

DESIGN

Population-based, retrospective cohort study.

SETTING

British Columbia, Canada.

POPULATION: Term, singleton deliveries (2004-2014) by attempted midcavity operative vaginal delivery or caesarean delivery in the second stage of labour, stratified by indication for operative delivery (n = 10 901 deliveries; 5057 indicated for dystocia, 5844 for fetal distress).

METHODS

Multinomial propensity scores and mulitvariable log-binomial regression models were used to estimate adjusted rate ratios (ARR) and 95% confidence intervals (95% CI).

MAIN OUTCOME MEASURES: Composite severe perinatal morbidity/mortality (e.g. convulsions, severe birth trauma and perinatal death) and severe maternal morbidity (e.g. severe postpartum haemorrhage, shock, sepsis and cardiac complications).

RESULTS

Among deliveries with dystocia, attempted midcavity operative vaginal delivery was associated with higher rates of severe perinatal morbidity/mortality compared with caesarean delivery (forceps ARR 2.11, 95% CI 1.46-3.07; vacuum ARR 2.71, 95% CI 1.49-3.15; sequential ARR 4.68, 95% CI 3.33-6.58). Rates of severe maternal morbidity/mortality were also higher following midcavity operative vaginal delivery (forceps ARR 1.57, 95% CI 1.05-2.36; vacuum ARR 2.29, 95% CI 1.57-3.36). Among deliveries with fetal distress, there were significant increases in severe perinatal morbidity/mortality following attempted midcavity vacuum (ARR 1.28, 95% CI 1.04-1.61) and in severe maternal morbidity following attempted midcavity forceps delivery (ARR 2.34, 95% CI 1.54-3.56).

CONCLUSION

Attempted midcavity operative vaginal delivery is associated with higher rates of severe perinatal morbidity/mortality and severe maternal morbidity, though these effects differ by indication and instrument.

TWEETABLE ABSTRACT: Perinatal and maternal morbidity is increased following midcavity operative vaginal delivery.