Relatively short interpregnancy interval poses low repeat miscarriage risk
An interpregnancy interval of less than 3 months following pregnancy loss presents the lowest risk of subsequent miscarriage, as suggested in a recent study.
The study drew data from the Right From the Start community-based prospective cohort and included 514 pregnant women whose most recent pregnancy before enrolment ended in miscarriage.
Researchers analysed the risk of miscarriage (defined as pregnancy loss before 20 weeks of gestation) in relation to interpregnancy interval (defined as the time between a prior miscarriage and the last menstrual period) lengths using Cox proportional hazard models. Maternal age, race, parity, body mass index and education were included as potential confounders.
Median maternal age of the study population was 30 years (interquartile range, 27 to 34), and 286 (55.6 percent) participants had at least one previous livebirth (n=286). Repeat miscarriage was reported in 81 (15.7 percent) women.
The risk of miscarriage was especially lower among women with pregnancy intervals of <3 months (n=124) than among those with interpregnancy intervals of 6 to 18 months (n=136; 7.3 vs 22.1 percent; adjusted hazard ratio 0.33; 95 percent CI, 0.16 to 0.71).
Factors such as maternal race and parity did not modify the observed association. Furthermore, attempting to conceive immediately did not contribute to an increase in the risk of miscarriage in the next pregnancy.
The finding that a relatively short interpregnancy interval is associated with the lowest risk of repeat miscarriage implies that counselling women to delay conception to reduce risk of miscarriage may not be warranted, researchers said.