Midpelvic forceps and midpelvic vacuum deliveries may be associated with a higher rate of both maternal and infant trauma than some other types of deliveries, according to a new study published in CMAJ.
Researchers in Quebec looked at all singleton deliveries in Canada that occurred between 2003 and 2013, by either attempted midpelvic operative vaginal or cesarean delivery with labor, with and without a prolonged second stage. Primary outcomes examined were composite severe maternal morbidity and mortality and composite severe perinatal morbidity and mortality.
During the study period, 187,234 deliveries were recorded. In women with prolonged second stage labor and dystocia, midpelvic operative delivery was associated with higher rates of severe perinatal morbidity and mortality when compared to cesarean (forceps, adjusted odds ratio [AOR] 1.81, 95% confidence interval [CI] 1.24 to 2.64; vacuum, AOR 1.81, 95% CI 1.17 to 2.80; sequential instruments, AOR 3.19, 95% CI 1.73 to 5.88). Severe maternal morbidity and mortality rates were not significantly different following an operative vaginal delivery, but obstetric trauma rates were higher (forceps, AOR 4.51, 95% CI 4.04 to 5.02; vacuum, AOR 2.70, 95% CI 2.35 to 3.09; sequential instruments, AOR 4.24, 95% CI 3.46 to 5.19). In women with fetal distress, similar associations were seen for severe birth and obstetric trauma, but the vacuum was linked with lower rates of severe maternal morbidity and mortality (AOR 0.52, 95% CI 0.33 to 0.80). Stronger associations were seen among women without a prolonged second stage.
The researchers concluded that while overall rates of perinatal and maternal morbidity and mortality vary by operative instrument and indication, midoperative delivery is linked with higher rates of severe birth and obstetric trauma.