In stratified analyses, there was a significant benefit of low-dose aspirin in the subset meeting the restricted pregnancy loss criteria (62.4% vs. 53.2%, P = .04) but not in the subset meeting the general pregnancy loss criteria (53.9% vs. 52.2%).
When the investigators more closely assessed the reason for benefit in the women meeting restricted criteria, they found a higher rate of achieving a positive pregnancy test with low-dose aspirin (70.5% vs. 61.7%, P = .03). Rates of progression thereafter to confirmed pregnancy by ultrasound at 6 weeks and ultimately to live birth were similar for the two treatment groups.
Dr. Schisterman disclosed no relevant conflicts of interest.