Sporadic and recurrent luteal phase defects in cyclic women: comparison with normal cycles

Luteal phase defects occurred sporadically in one and repeatedly in three cyclic women. Daily blood levels of prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormones (FSH), total estrogen, and progestin (P) were measured in these cycles with luteal insufficiency. Although the short cycle which occurred sporadically had a luteal phase of 6 days' duration, results of the daily hormonal evaluation of this cycle were within the normal range with the exception of an inappropriate FSH:LH ratio and a P level of 2 SD below normal on the 6th postovulatory day. Previous and subsequent study cycles of this subject were completely normal. The three cycles with recurrent luteal phase defects demonstrated the following general deviations from normal values: (1) elevated PRL concentrations, more specifically during the periovulatory phase; (2) absence of a midcycle FSH surge; (3) inappropriate FSH:LH ratios; and (4) subnormal P levels in amount and/or duration during the luteal phase. The clinical significance of these findings is discussed.