Age at menarche and clinical outcomes following medically assisted reproduction (MAR): a cohort study.

Medically assisted reproduction (MAR) technologies have advanced rapidly, but in contrast to the specificity of modern approaches, they provide limited effectiveness in the management of the infertile couple. The purpose of this study was to assess the possible relationship between age at menarche and MAR outcomes of clinical pregnancy, live birth and the adverse incident of miscarriage, and to determine the offspring sex ratio according to age at menarche. In a cohort of 254 infertile couples who underwent 426 IVF/ICSI cycles, statistical analysis was performed by applying Student's t-test, chi-square test, and logistic regression models, adequately in the respective parameters and outcomes. The results indicated a strong association of age at menarche with the outcomes of clinical pregnancy (p = .0007) and live birth (p < .0001), especially by applying a threshold of 12 years in the first occurrence of menstruation (p = .0019 for clinical pregnancy, p < .0001 for live birth), also demonstrating a negative effect for earlier menarche that acts in parallel with the increasing age of the woman. Calculation of sex ratio demonstrated a tendency towards female offspring close to the age at menarche of 12 years. Age at menarche could serve as a surrogate parameter for reproductive potential towards personalized management of infertility.