OC16.06: Fetal and neonatal events associated with low‐dose aspirin during the first trimester of pregnancy: secondary analysis of the ASPIRIN trial

To determine if there is a difference in the incidence of fetal and neonatal adverse events based on the gestational age of low-dose aspirin (LDA) initiation (<11.0 vs. ≥11.0 weeks). This was a secondary analysis of the ASPIRIN trial in which nulliparous women were randomised to LDA (81mg daily) or placebo between 6+0/7 and 13+6/7 weeks of gestation. A subgroup analysis was performed to assess if there is a difference regarding fetal and neonatal adverse events (i.e. at least one serious adverse event, fetal loss, neonatal death up to 28 days, miscarriage, abortion, or medical termination of pregnancy, congenital anomalies) among participants who started LDA before or after 11.0 weeks of gestation. Logistic regression was used to assess the interaction between the subgroup mentioned above and the exposure. Results are presented with a P-value for interaction and corresponding odds ratios. There was no evidence of heterogeneity in the incidence of adverse fetal and neonatal events based on gestational age of LDA initiation (see figure 1): at least one serious adverse event (P-value for interaction 0.952), fetal loss (P-value for interaction 0.446), neonatal death up to 28 days (P-value for interaction 0.304), miscarriage, abortion, or medical termination of pregnancy (P-value for interaction 0.585), congenital anomalies (P-value for interaction 0.105). There was no significant heterogeneity in the incidence of fetal or neonatal adverse events between patients who started LDA consumption before or after 11.0 weeks of gestation. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.