Adverse perinatal and neonatal outcomes in patients with chronic abruption-oligohydramnios sequence

Chronic abruption-oligohydramnios sequence (CAOS) is a clinical condition with lasting vaginal bleeding and oligohydramnios because of chronic placental abruption, which seems to cause preterm labor and neonatal chronic lung disease (CLD). This prompted us to explore the correlation between perinatal/neonatal outcomes and CAOS.

Patients with suspected risk of abortion with recurrent vaginal bleeding were divided into CAOS and non-CAOS groups, and we compared the perinatal/neonatal outcomes between these two groups. To examine the impact of chorioamnionitis (CAM) on the prognosis of CAOS, we also compared outcomes between the CAOS group and gestational-age-matched preterm labor due to CAM (CAM group).

In the CAOS and non-CAOS groups, initial vaginal bleeding was seen at the first trimester. However, its duration was significantly longer in the CAOS group. Additionally, neonatal birthweight was lower, and small-for-gestational-age (SGA) incidence was higher in the CAOS group. CLD was observed in most infants from CAOS patients. In the comparison between CAOS and CAM groups, birthweight was lower and SGA incidence was higher in the CAOS group. Moreover, CLD incidence and neonatal mortality were significantly higher, despite the lower incidence of severe CAM in the CAOS group. Finally, multivariate analysis demonstrated that duration of bleeding was a significant predictive factor for CAOS.

Our observations demonstrated that patients with CAOS were a high-risk group for poor perinatal/neonatal outcomes. Moreover, episodes of recurrent and prolonged uterine bleeding were predictive factors for CAOS. During the first trimester, prolonged bleeding is an important sign as one symptom of CAOS.