Figure 1.

LH, FSH, E2, and P4 levels during two consecutive menstrual cycles in adolescent girls with either normal OV (left, n = 11) or short OV (right, n = 5) cycles. Levels represent serum or serum equivalents as determined from DBS or urine samples. Cycle days are centered to the MC LH peak of cycle 1 (day 0) and shown during the first week of cycle 2 (day 1 = menses). Adolescents: filled circles are arithmetic mean values and error bars are ±1 SE. Both groups are compared with historic adult controls (n = 65). Adults: Dashed line denotes arithmetic mean level and shaded area is ±1 SD. *P < 0.05; **P < 0.01; ***P < 0.001 for cycle phase (i.e., LFP, MC, LP, EFP). To convert E2 to SI units (pmol/L), multiply by 3.67; for P4 (nmol/L), multiply by 3.18.