(195) Episiotomy and Obstetric Anal Sphincter Injury in Nulliparous Women with Prolonged Second Stage.

Allowing a prolonged second stage of labor in nulliparous women remains controversial. A significant concern is the increased risk of obstetric anal sphincter injuries (OASIS). This study assesses whether routine episiotomy can effectively reduce OASIS occurrence in nulliparous women undergoing vaginal delivery following a prolonged second stage.

Study Design:

This retrospective study examined nulliparous women with singleton pregnancies who had a second stage of labor lasting≥3 hours and ultimately achieved spontaneous, non-operative, vaginal delivery between 2014-2024. Participants were grouped by episiotomy status: with and without episiotomy. The primary outcome was the occurrence of OASIS, namely third- and fourth-degree perineal lacerations. The main secondary outcomes comprised maternal and neonatal measures.

Results:

Compared to the no-episiotomy group, women in the episiotomy group were younger (27.79±4.3 vs. 28.47±4.5 years, p< 0.001), had slightly longer second stage (3.62±0.4 vs. 3.53±0.4 hours, p< 0.001), and higher birthweight (3366±390 vs. 3284±376 grams, p< 0.001). As shown in Figure 1, OASIS rates were comparable between the groups (1.9% vs. 2.2%, p=0.82), consistent across all subtypes, and in a subanalysis of women with a second stage of ≥ 4 hours (2.9% vs. 2.5%, p=0.588). Table 1 presents the secondary clinical outcomes: women who underwent episiotomy reported significantly greater postpartum pain during hospitalization (VAS score: 4.06±3.2 vs. 3.61±3.1, p=0.003). Notably, despite this increased discomfort, they  demonstrated a significantly higher rate of breastfeeding initiation (65.1% vs. 50.7%; p<span class="msoDel"> = =0.01). Other maternal and neonatal outcomes did not differ significantly.

Conclusion:

In nulliparous women with a prolonged second stage, routine episiotomy did not reduce the risk of OASIS. Although associated with increased postpartum pain, it was linked to higher breastfeeding initiation rates. These findings support existing guidelines advocating against routine episiotomy in this population. Further research is warranted to validate our findings and refine management strategies.