The Association Between Early Menarche and Preterm Birth

Exploring healthcare outcomes throughout a females reproductive life is an important area of research that is in need of more investigation. Specifically, there is a limited body of evidence available that explores the association between early reproductive behaviours and future pregnancy outcomes. Yet there is increasing evidence that points towards a relationship between the age at menarche and an increased risk for preterm birth. Therefore, this thesis explored the relationship between early age at menarche and the risk of preterm birth among a cohort of Canadian women. Responses from the Ontario Birth Study, a retrospective pregnancy-based cohort study, was used for the analysis. Summary statistics and a multivariable logistic regression were conducted, adjusting for covariates. Overall, 17% of the sample experienced early menarche. Additionally, 4.2% of all survey participants experienced a preterm birth. In total, 7.0% of women who experienced an early age at menarche went on to deliver preterm. The unadjusted association between early menarche and preterm birth was statistically significant; however, after adjusting for all covariates, the relationship was no longer significant. Significant determinants of a preterm birth included women who had any hypertensive disorders throughout their pregnancy, had fetal complications, or any placental issues prior to delivery. Conversely, those in the highest income group were at a decreased risk of a preterm birth. Recognizing risk factors is an important step to aid healthcare providers mitigate the risks associated with preterm birth. Future investigations are needed to probe deeper into the field and tease out social and environmental intricacies.