Perinatal & Pediatric
A prospective preconception cohort study of the association between miscarriage history and fecundability in Kenyan women trying to conceive Hanna Shephard* Hanna Shephard Shephard Shephard Shephard Shephard Shephard Department of Epidemiology, University of Washington, Seattle, WA, USA; Pwani Research Centre, Kenya Research and Training Center, University of Washington, Mombasa, Kenya
Background: Emerging evidence suggests that a prior miscarriage might impair subsequent fecundability, defined as the per-menstrual cycle probability of conception. However, existing studies are from high-income settings, leaving a gap in the evidence from low- and middle-income countries. The Microbiota and Pre-term Birth (MPTB) Study is a prospective, preconception cohort of HIV-negative Kenyan women trying to conceive.
Objective: To test the hypothesis that miscarriage history is associated with reduced fecundability among women in the MPTB Study.
Methods: At enrollment, participants reported outcomes of prior pregnancies (miscarriage, termination, ectopic pregnancy, stillbirth, or live birth). Participants were followed prospectively for up to six months. At monthly visits, participants reported the date of their last menstrual period and underwent pregnancy testing to ascertain incident pregnancies. The exposure was self-reported miscarriage history prior to enrollment, defined as spontaneous abortion at <20 weeks’ gestation. We fit discrete-time proportional probability models to estimate fecundability ratios (FRs) and 95% confidence intervals (CI) comparing women with a history of one or more miscarriages to women with no history of miscarriage.
Results: Among 423 gravid participants, 22.5% had a history of one or more miscarriages. In unadjusted analyses, miscarriage history was associated with slightly reduced fecundability (FR 0.88, 95% CI: 0.66—1.17), although confidence intervals were wide. After adjustment for age at enrollment. study site, education, body mass index, regularity of menses, vaginal washing and condomless sex behavior, and sexually transmitted infections, the association was further attenuated (FR 0.93, 95% CI: 0.69—1.25) and confidence intervals remained wide.
Conclusions: Among MPTB study participants, miscarriage history may be associated with slightly associated lower fecundability, but estimates were imprecise and confidence intervals encompassed the null.