(1114) Effect of aspirin and early onset fetal growth restriction Doppler severity

Early onset fetal growth restriction (FGR) is a diagnosis with significant impacts on neonatal outcomes driven by the need for preterm delivery as often is determined by Doppler severity. Preeclampsia is a known risk factor for placental insufficiency associated with early onset FGR. Given the widespread use aspirin to reduce risk of preterm preeclampsia, we aimed to determine if aspirin use was associated with a reduced risk of Doppler severity and progression of early onset FGR.

Study Design:

We performed a retrospective cohort study at a single academic institution of patients with early onset FGR (< 32 weeks) from 8/10/2016 to 4/17/2024. Chart review was performed to evaluate singleton, nonanomalous pregnancies with a diagnosis of early onset FGR and the association between aspirin use and gestational age at diagnosis, umbilical artery Doppler severity, and gestational age at delivery. The Mann-Whitney test was used to compare the continuous variable. Categorical variables were compared using Fisher’s exact test.

Results:

A total of 255 patients were included in the study sample with the majority being non-aspirin users (215 vs 40). Mean gestational age at diagnosis was 26.0 weeks for aspirin user compared to 26.5 for non-aspirin users (p = 0.256). Aspirin use did not alter the severity of Dopplers at time of diagnosis, with the majority of patients having normal Dopplers. For those diagnosed at less than 28w, 92% of the patients on aspirin had normal umbilical artery Dopplers at diagnosis compared to 81.8% of the patients not taking aspirin (p=0.181). There was no difference in rates of preterm delivery based on aspirin use, and the majority of patients delivered after 37w (67%).

Conclusion:

Aspirin did not alter the severity of early onset FGR based on gestational age at diagnosis, severity of initial Doppler value, and gestational age at delivery. This is consistent with previous literature that aspirin is not effective at altering FGR outcomes or incidence.