Endometrial cytosolic and nuclear progesterone receptors in the luteal phase defect

Basal body temperature profiles, serial serum progesterone levels, and serial endometrial biopsies were studied in 15 infertile women during 21 ovulatory cycles. Ten cycles (in 9 women) demonstrated luteal phase defects (LPD), diagnosed by a histological lag in endometrial maturation, normal luteal phase length, and normal luteal phase serum progesterone levels. Both normal and LPD cycles had a maximum amount of endometrial cytosolic progesterone receptor (PgR) on days 13-15, with a significant decline thereafter. LPD cycles had significantly lower endometrial nuclear PgR concentrations than did normal cycles during the proliferative phase, but luteal phase endometrial nuclear PgR levels were similar in both groups. In 2 LPD women treated with dydrogesterone, normal endometrial maturation and a decline in endometrial cytosolic PgR concentrations in the late luteal phase were found. Therefore, with the exception of endometrial nuclear PgR concentrations during the proliferative phase, we found no evidence for a major abnormality in endometrial PgR levels in LPD cycles with a lag in endometrial histology.