(441) Subsequent Pregnancy Outcomes After Nulliparous Second-Stage Cesarean Versus Operative Vaginal Delivery

Second-stage cesarean (CS) is associated with an increased risk of future preterm birth. We compared pregnancy and delivery outcomes in subsequent pregnancies following CS for second-stage arrest to outcomes in those with operative vaginal deliveries (OVD) in order to control for the second stage of labor.

Study Design:

This was a retrospective cohort study of nulliparous patients with a singleton term birth from 2017 to 2020 and subsequent pregnancy at our institution. Patients with second-stage CS and OVD were compared. Data was abstracted from the electronic medical record. Primary outcomes were cervical insufficiency, preterm birth, and gestational age (GA) at delivery in subsequent pregnancy. Secondary outcomes were mode of delivery, birth characteristics, and neonatal outcomes.

Results:

We identified 180 second-stage CS and 214 OVD. There was no difference between groups in diagnosis of short cervix, initiation of vaginal progesterone, cerclage placement, or rates of preterm birth in subsequent pregnancies (Table 1). The majority of patients in the OVD group had a subsequent vaginal birth (VB) (87.9%) compared to 22.2% in the second-stage CS group (p < 0.001).  Among those with subsequent VB, the second-stage CS group were more likely to present in spontaneous labor (91.8% vs. 59.5%, p = 0.002). The median length of second stage in subsequent VB was longer for prior second-stage CS vs. OVD (66 vs. 23 min, p < 0.0001). Among those with subsequent CS, the OVD group was more likely to have an intrapartum or urgent indication for CS. In the second-stage CS group, 65% elected or were counseled to have a scheduled subsequent CS. However, only 26% of those attempting secondary VB failed. Neonatal outcomes between groups were overall similar.

Conclusion:

There were no inter-group differences in rates of preterm birth or cervical insufficiency. Interestingly, of those with a subsequent VB, those in the second-stage CS group were more likely to present in spontaneous labor.