Unplanned Cesarean Delivery in the Second Stage of Labor Holds Higher Odds of Complications than in the First Stage, while Similar in Primiparas and Multiparas

Background: While endeavors to reduce cesarean delivery (CD) rates are given priority worldwide, it is important to evaluate if these efforts place parturients and neonates at risk. CD performed in the second stage of labor carries higher risks of maternal and fetal complications and is a more challenging surgical procedure than that performed in the first stage or before labor. In a population with a low CD rate, we sought to evaluate the rate of maternal and fetal complications associated with unplanned CD (UCD) performed in the second vs. the first stage of labor, in primiparas and multiparas, as well as the risk factors leading to and the complications associated with UCD in the second stage of labor in this low-CD rate setting. Methods: This was a retrospective, electronic medical record-based study of 7,635 term and preterm singletons born via UCD in the period 2003-2015. Maternal and neonatal background and outcome parameters were compared between groups. Logistic regression modeling was applied to adjust for clinically and statistically significant risk factors. Results: UCD was more likely to be performed in the second stage of labor in mothers delivering larger fetuses (head circumference and body weight ≥90 centile) and those with persistent occiput posterior (POP) presentation. UCD in the second stage was strongly associated with serious maternal complications (excessive hemorrhage and fever) compared to UCD performed in the first stage, in both primiparas and multiparas. Conclusions: UCD performed in the second stage of labor, while less frequent than first-stage UCD, is more likely with larger neonates and POP presentation, and is associated with a higher rate of maternal complications in primiparas and multiparas. Complication rates in our low-CD-rate population did not exceed those reported in the literature from high-CD-rate areas.