Subsequent pregnancy outcomes according to the presence of acute histologic chorioamnionitis in women with spontaneous preterm delivery

OBJECTIVE: To compare subsequent pregnancy outcomes according to the presence of acute histologic chorioamnionitis (HCA) in women with spontaneous preterm delivery (SPTD). METHODS: Among 1,706 women who gave birth twice or more at our institution, 138 women delivered spontaneously at preterm (<37.0 weeks). Subsequent deliveries occurred at our institution and placental biopsy results were available. The study population was categorized into 2 groups based on the presence of acute HCA at the time of SPTD: HCA group (n=52) and non-HCA group (n=86). The primary outcome measures were gestational age at delivery, birthweight, and frequency of preterm delivery in subsequent pregnancies. RESULTS: The median gestational age at the time of SPTD was 34.0 weeks (interquartile range [IQR], 28.9–35.3 weeks), and the frequency of acute HCA was 52/138 (38%). There were no differences in gestational age at delivery, birthweight, and frequency of preterm delivery between the HCA group and non-HCA group (median gestational age at delivery, 38.0 weeks (IQR, 36.7–38.8 weeks) in the HCA group vs. 37.9 weeks (IQR, 35.7–39.0 weeks) in the non-HCA group; frequency of preterm delivery, 14/52 (27%) in the HCA group vs. 33/86 (38%) in the non-HCA group; and median birthweight, 3.14 kg (IQR, 2.64–3.45 kg) in the HCA group vs. 2.95 kg (IQR, 2.44–3.36 kg) in the non-HCA group; P>0.1 for all. CONCLUSION: The presence of acute HCA in women at prior SPTD did not significantly affect their subsequent pregnancy outcomes.