Measurements of salivary progesterone throughout the menstrual cycle in women suffering from unexplained infertility reveal high frequency of luteal phase defects.

Forty-five women suffering from unexplained infertility collected saliva for progesterone (P) measurements every morning during 1 to 3 complete cycles. A total of 27 cycles analyzed were unstimulated, 19 were stimulated by clomiphene citrate (CC), and 7 with CC, human menopausal gonadotropin (hMG), and human chorionic gonadotropin (hCG). Compared with reference profiles of salivary P from 27 normal cycles, the length and magnitude of P secretion were significantly lower in the infertility group. Luteal P concentrations were normalized during CC stimulation and significantly elevated during the CC-hMG-hCG stimulation. The other abnormalities found in the salivary P profiles of these patients included preovulatory P peaks, interruption of P secretion during luteal phase, and high P level at the beginning of menstruation. The results suggest that patients with prolonged unexplained infertility represent a heterogenous population with common luteal phase defects. The disturbance is effectively corrected with treatments stimulating gonadotropin secretion.