Labor Characteristics and Maternal-Infant Outcomes in Preterm Primiparous Women

This retrospective observational study evaluates labor characteristics in primiparous women with spontaneous preterm birth at different gestational ages and examines their associations with maternal and neonatal outcomes. Medical records of women who delivered at Shanghai Jiading District Maternity and Child Health Care Hospital between January 1, 2020, and December 31, 2025, are reviewed. Participants are classified according to gestational age at delivery into very preterm (28 to 31+6 weeks), moderate preterm (32 to 33+6 weeks), and late preterm (34 to 36+6 weeks) groups. The study compares the onset and duration of the active phase of labor, cervical dilation rate, and durations of the first and second stages of labor across these gestational-age groups. The study also evaluates the associations between labor duration and maternal and neonatal outcomes, including postpartum blood loss, mode of vaginal delivery, and 5-minute Apgar score. The findings are intended to provide evidence for gestational age-specific and individualized labor management in women with spontaneous preterm birth.