Gestational age-stratified management of umbilical artery thrombosis: a 5-year retrospective study at a tertiary referral center in China

Umbilical artery thrombosis (UAT), a rare yet critical obstetric condition, is associated with a spectrum of adverse perinatal outcomes. This retrospective study aimed to investigate the perinatal outcomes of pregnant women diagnosed with UAT at different gestational ages, and compare the neonatal outcomes between expectant management and emergency cesarean delivery following UAT diagnosis. In this retrospective study, 67 pregnant women with UAT were included and stratified into the groups of < 28 weeks (n = 8), 28–33⁺⁶ weeks (n = 30), and ≥ 34 weeks (n = 29) based on the gestational age at diagnosis. Baseline characteristics, management strategies, and perinatal outcomes were compared among the three groups. The utilization rate of low molecular weight heparin (LMWH) in the group of < 28 weeks was significantly higher than that of ≥ 34 weeks (87.50% vs. 13.79%, p < 0.001). Compared to the ≥ 34-week group, the groups of < 28 weeks and 28–33⁺⁶ weeks demonstrated a higher rate of expectant management, an earlier gestational age at delivery, and a longer time of pregnancy prolongation (all p < 0.05). Neonatal birth weight increased with increasing gestational age at UAT diagnosis, in which the group of ≥ 34 weeks had higher birth weight than those of < 28 weeks (p = 0.031) and 28–33⁺⁶ weeks (p = 0.003). Neonates in the earlier gestational age groups required significantly longer neonatal intensive care unit (NICU) stays (all p < 0.001). Notably, in the group of < 34 weeks, expectant management showed a higher delivery gestational age (p = 0.020) and a lower NICU admission rate (p = 0.024) than emergency cesarean delivery, while in the ≥ 34-week group no statistically significant differences were observed. In this retrospective study, expectant management was associated with higher delivery gestational age and lower NICU admission rate than emergency cesarean delivery for UAT diagnosed before 34 weeks, whereas no significant differences between the two strategies were observed for diagnoses at or after 34 weeks. These hypothesis-generating findings require validation in prospective, multicenter studies.