Association of preconception dysmenorrhea with obstetric complications: the Japan Environment and Children's Study

BACKGROUND: The association of maternal preconception dysmenorrhea, especially primary dysmenorrhea, with obstetric complications has not been clearly described. Therefore, we evaluated the association of preconception dysmenorrhea with obstetric complications while accounting for the presence of pelvic pathologies. METHODS: We analyzed the data of women with singleton live births at and after 22 weeks of gestation enrolled in the Japan Environment and Children's Study, a nationwide birth cohort study, between 2011 and 2014. Participants with psychological disorders were excluded. Preconception dysmenorrhea, identified in the medical record transcripts, was categorized into mild dysmenorrhea (MD) and severe dysmenorrhea (SD). Furthermore, excluding those who had pelvic pathologies via self-reported questionnaires (endometriosis, adenomyosis, and uterine myomas) with MD and SD, preconception dysmenorrhea was categorized into mild primary dysmenorrhea (MPD) and severe primary dysmenorrhea (SPD), respectively. Using multiple logistic regression, adjusted odds ratios (aORs) for obstetric complications, including preterm birth (PTB) before 37 weeks and 34 weeks, small-for-gestational-age infants, preterm premature rupture of membrane, and hypertensive disorders of pregnancy, were calculated (considering confounders) in women with (1) MD or SD and (2) MPD or SPD. Women without preconception dysmenorrhea were used as a reference. RESULTS: A total of 80,242 participants were analyzed. In women with SD, the aOR for PTB before 37 weeks was 1.38 (95% confidence interval [CI] 1.10, 1.72). In women with SPD, the aOR for PTB before 37 weeks was 1.32 (95% CI 1.02, 1.71). There was no association between women with MD or MPD and obstetric complications. CONCLUSIONS: SD and SPD are significantly associated with an increased incidence of PTB before 37 weeks. Care providers should provide proper counseling regarding the association between preconception dysmenorrhea and obstetric complications. Optimal management of pregnant women with preconception dysmenorrhea to reduce the incidence of PTB should be elucidated in further studies, with detailed clinical data of pelvic pathologies.