PubMed Health writes that a miscarriage is the spontaneous loss of a fetus prior to the 20th week of pregnancy. When pregnancy losses occur after the 20th week it is called preterm deliveries. A miscarriage is also called a "spontaneous abortion." This is in reference to naturally occurring events, not to medical abortions or surgical abortions. Crystal Phend has reported on Feb. 16, 2013 for MedPage Today, Aspirin May Up Chance for Baby After Miscarriage.
A clinical trial has showed that low-dose aspirin may boost a woman's chance of having a live-birth baby after a recent miscarriage. Enrique Schisterman, PhD, of the National Institute of Child Health and Human Development in Rockville, Md., and colleagues have found that women who had one documented miscarriage at less than 20 weeks gestational age during the prior year were 9.2 percentage points more likely to have a live birth if they took a daily aspirin rather than placebo while they were trying to conceive. However, it was found this effect didn't carry over to a broader group of women who had lost one or two pregnancies at any gestational age some time in the past.
Kathryn Menard, MD, MPH, director of maternal-fetal medicine at the University of North Carolina at Chapel Hill, has said, "It's safe to say that this is not an intervention for everyone who's trying to become pregnant." However, it would likely be recommended for the subgroup who have had a loss less than 20 weeks based on results like these. Schisterman has acknowledged the need for further study, but has suggested it wasn't an unreasonable strategy to try in the meantime. It is hypothesized that aspirin reduces inflammation and improves blood flow to the uterus and other key structures.