Objective: Uterine scarring is risky for the pregnancy and is closely associated with adverse pregnancy outcomes. Here, we investigated risk factors and associated perinatal outcomes in singleton pregnant women with uterine scars.
Methods: This retrospective cohort study was conducted on singleton pregnant women who delivered at the West China Second University Hospital between January 1, 2021, and December 31, 2021.
Results: The control group included 13,433 cases without uterine scars. The study group involved 2397 cases with one previous cesarean delivery (PCD), 163 cases with two PCDs, 12 cases with three PCDs, and 184 cases with non-cesarean uterine scars. The study group had a significantly higher incidence of placenta previa (6.4%), placenta percreta (5.3%), preterm delivery (10.3%), postpartum hemorrhage (3.4%), uterine rupture (9.4%), hysterectomy (0.18%), and bladder injury (0.4%) when compared with the control group (P < 0.05). The scarred uterus cases with 1, 2, or 3 PCDs had significantly different complications, with the higher PCD frequency correlating with increased rates of placenta previa, placenta percreta, postpartum hemorrhage, uterine rupture, and uterine resection. Moreover, the hospitalization time, cesarean operation time, and intrapartum bleeding in the current pregnancy significantly increased with increasing PCD frequency (P < 0.05). Analysis of the association between the duration of the interval between PCD and re-pregnancy and pregnancy complication revealed that the incidence of pernicious placenta previa was statistically higher in cases with intervals of < 2 years or ≥ 5 years (4.7%) than in cases with 2 years ≤ interval time < 5 years (2.5%) (P < 0.05).
Conclusion: Pregnancies with uterine scars may experience higher rates of adverse perinatal outcomes. This calls for increased observation during pregnancy and delivery to reduce maternal and fetal complications.
Keywords: scarred uterus, perinatal outcomes, singleton pregnancy, uterine rupture, pernicious placenta previa