Reconsidering the effectiveness of low-dose aspirin in prevention of pre-eclampsia among otherwise low risk twin gestations: A historical cohort study

Objective: To investigate the effectiveness of low-dose aspirin (LDA) in the prevention of pre-eclampsia (PE) among otherwise low-risk twin gestations. Methods: A historical cohort study consisting of all pregnant individuals with dichorionic diamniotic (DCDA) twin pregnancy who delivered between 2014 and 2020. Patients treated with LDA were matched by a 1:4 ratio to individuals who were not treated with LDA by age, body mass index and parity. Results: During the study period, 2271 individuals carrying DCDA pregnancies delivered at our center. Of these, 404 were excluded for one or more additional major risk factors. The remaining cohort consisted of 1867 individuals of whom 142 (7.6%) were treated with LDA and were compared with a 1:4 matched group of 568 individuals who were not treated. The rate of preterm PE did not differ significantly between the two groups (18 [12.7%] in the LDA group vs. 55 [9.7%] in the no-LDA group; P = 0.294, adjusted odds ratio 1.36, 95% confidence interval 0.77–2.40). There were no other significant between-group differences. Conclusions: Low-dose aspirin treatment in pregnant individuals with DCDA twin gestations without additional major risk factors was not associated with a reduction in the rate of preterm PE.