Mode of preterm delivery and risk of recurrent preterm delivery, a multicenter retrospective study

Objective: To examine whether mode of preterm delivery is associated with the risk of recurrent preterm delivery in subsequent pregnancy. Study design: A multicenter retrospective study. Women with the first two consecutive singleton deliveries at two university-affiliated medical centers between August 2005-March 2021, with first delivery occurring spontaneously < 37 weeks of gestation were included. Excluded were women with multifetal pregnancies in either pregnancy and those with an indicated first preterm delivery. A univariate analysis was followed by a multivariate analysis. Results: A total of 1,019 women with spontaneous preterm first delivery were included. Of those, 141 (13.8 %) underwent cesarean delivery in their first preterm delivery, while 878 (86.2 %) had a vaginal delivery. Univariate analysis revealed that women who underwent cesarean delivery in their first delivery had, during the subsequent delivery: longer mean gestational age at delivery (37.8 ± 3.3 vs 36.8 ± 3.7 weeks; p < 0.01), but statistically similar rates of recurrent preterm delivery both < 37 weeks and < 34 weeks (23.4 % vs 27.2 % and 7.1 % vs 10.6 %; p = 0.34 and p = 0.20, respectively). Multivariate analysis revealed that mode of delivery- cesarean – in the preterm delivery was not associated with recurrent pre-term delivery (0.66 (0.41–1.04), p = 0.07). Conclusion: Mode of delivery in first preterm delivery is not associated with higher or lower rates of recurrent preterm delivery.