Development of Ovulatory Menstrual Cycles in Adolescent Girls

Abstract

Irregular menstrual cycles due to anovulation are well described in the first few years after menarche, but the normal developmental trajectory from anovulatory to mature ovulatory cycles during adolescence remains undefined. In this article we review the very limited understanding of this final stage of female reproductive axis development and discuss why additional research in this area is critical to the health of women.

Keywords: Anovulation; Menstrual cycle; Ovulation; Progesterone.

Figure 1.

Box and whisker plots demonstrating variability among 14 studies in the reported percentage of girls with ovulatory cycles according to gynecologic age (years since menarche). In these studies, ovulatory status had been determined using either urine ^,, serum ^,,, or saliva hormone tests ^,,, cycle length ^,,,, or a shift in basal body temperature . References used to calculate summary statistics for each gynecologic year are listed at the bottom of the figure.

Figure 2.

Serum LH, FSH, estradiol (E2), and progesterone (P4) levels during two consecutive menstrual cycles in 3 representative adolescent subjects (A, B, C). Hormone data for subjects A, B, and C are shown in the left, middle, and right columns, respectively. Each subject’s data are plotted against a backdrop of normative data from 65 historic adult controls with regular, ovulatory cycles. Days are centered to the midcycle LH peak in cycle 1 (day 0). Adult data are presented as mean (dashed line) ± 1 SD (shaded area). A) 13 ½ -year-old (gynecologic age of 9 mo) subject with a 33-day ovulatory cycle with a normal luteal phase length of 12 days. B) 15 ½-year-old (gynecologic age 2.8 years) subject with a 24-day ovulatory cycle with short luteal phase length of 5 days. C) 13-year-old (gynecologic age 7 mo) subject with a 42-day anovulatory cycle due to a luteinized unruptured follicle. Initial cycle dynamics were relatively normal with growth of a dominant follicle (to a 30-mm diameter), an increase in E2, and an LH surge of 24.2 IU/L, but ovulation did not occur. The unruptured follicle continued to produce E2 and luteinized (maximum P4 3.9 ng/mL) until menses occurred 12 days later. To convert serum E2 to SI units (pmol/L), multiply by 3.67; for serum P4 (nmol/L), multiply by 3.18.