Outcomes of vertex-vertex vs. vertex-breech presentation in twin pregnancy after vaginal delivery in China.

OBJECTIVE: To compare the maternal and neonatal outcomes of twin pregnancies between vertex and nonvertex presentations of the second twin in vaginal delivery. METHODS: In this unicentric retrospective cohort study, we collected data from 213 cases of vaginal twin deliveries from January 2016 to July 2020. Participants were divided into the vertex-vertex presentation group (VV) and vertex-breech presentation group (VB). Data on maternal and neonatal outcomes were compared between groups. RESULTS: Among the 213 mothers and 426 infants (213 twin pairs), there were 140 women in the VV group and 73 women in the VB group (65.73% vs. 34.27%). Infants in the VB group had a higher incidence of admission to NICU (51.43% vs. 68.49%, p = 0.017), lower 1-min (11.43% vs. 28.77%, p < 0.001) and 5-minute Apgar scores (1.43% vs. 4.11%, p = 0.043) for the second twin. However, after the adjustment for sex of the twin, birth weight, chorionicity, and gestational age, the greater risk of admission to NICU and low 5-min Apgar score was no longer significantly different. CONCLUSION: VB twins are at no greater overall risk of a poor outcome due to breech presentation in the second twin. However, the presentation of the second fetus represents a risk factor for a low 1-min Apgar score. Obstetricians and midwives should consider appropriate interventions for second twins who present breech versus vertex.