Assens M, Dyre L, Henriksen LS, et al. - Researchers conducted the study for analyzing reproductive parameters in postmenarchal girls from the general population including the frequency of oligomenorrhea, polycystic ovary syndrome, and the use of hormonal contraception. The Copenhagen Mother-Child Cohort is a population-based longitudinal birth cohort of 1,210 girls who were born between 1997 and 2002. In total, 317 girls were involved, with a median age of 16.1 years and time since menarche of 2.9 years. Tanner stage, height, weight, age at menarche, menstrual cycle length and regularity, ovarian/uterine volume, and the number of follicles have been recorded. Data reported that 20 girls (6.3%) had oligomenorrhea and varied significantly in serum androgens and anti-Müllerian hormone (AMH), age at and time since menarche from girls with regular cycles. It was noted that 27 girls were diagnosed with PCOS and had significantly higher 17-OH-progesterone, estradiol, AMH, LH, and age at menarche than the reference group. Findings revealed that most girls aged 16 had regular menstrual cycles, normal reproductive hormones, and uterine and ovarian ultrasound. Serum AMH reflected ovarian follicle count and can be a useful ovarian reserve biomarker.