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.