Menstrual Pattern, Reproductive Hormones, and Transabdominal 3D Ultrasound in 317 Adolescent Girls

Context The knowledge of normal variation of reproductive hormones, internal genitalia imaging, and the prevalence of gynecological disorders in adolescent girls is limited. Objective The study aimed to describe reproductive parameters in postmenarchal girls from the general population including the frequency of oligomenorrhea, polycystic ovary syndrome, and use of hormonal contraception. Design The Copenhagen Mother-Child Cohort is a population-based longitudinal birth cohort of 1210 girls born between 1997 and 2002. Setting University hospital. Participants A total of 317 girls were included, with a median age of 16.1 years and time since menarche of 2.9 years. Main Outcome Measure(s) Tanner stage, height, weight, age at menarche, menstrual cycle length and regularity, ovarian/uterine volume, and number of follicles were recorded. Serum concentrations of FSH, LH, anti-Müllerian hormone (AMH), inhibin B, estradiol, testosterone, SHBG, androstenedione, dehydroepiandrosterone sulfate, 17-OH-progesterone, and IGF-1 were measured. Results Twenty girls (6.3%) had oligomenorrhea and differed significantly in serum androgens and AMH, age at and time since menarche from girls with regular cycles. Twenty-seven girls were classified with PCOS (8.5%) and had significantly higher 17-OH-progesterone, estradiol, AMH, LH, and age at menarche than the reference group. Girls on oral contraception had significantly higher serum SHBG concentrations and lower serum concentrations of all hormones except AMH and IGF-1. Ovarian follicles 2 to 29.9 mm correlated positively with serum AMH (P < 0.0001). Conclusions Most 16-year-old girls had regular menstrual cycles, normal reproductive hormones, and uterine and ovarian ultrasound. Serum AMH reflected ovarian follicle count and may be a useful biomarker of ovarian reserve.