Correlation of serum progestagen-associated endometrial protein levels with endometrial biopsies serum steroid levels and therapy for luteal phase defects.

The progestagen-associated endometrial protein (PEP) level rises from the early to the late luteal phase. A study was performed in infertile women where late luteal phase endometrial biopsies and serum PEP levels were obtained. The objective of the study was to evaluate the correlation between the PEP levels and the endometrial biopsies and to determine if subnormal PEP levels could be improved by the same therapies used to correct endometrial defects. There was a poor correlation between PEP levels and endometrial biopsies (r = 0.17). Similarly, there was no significant correlation between PEP levels and levels of the following hormones: mid- and late-luteal phase progesterone (P) (r = 0.186 and 0.282 respectively), mid-luteal phase 17-hydroxyprogesterone (17-OHP) (r = 0.139) and mid-luteal phase oestradiol (r = 0.135). Furthermore, there was no correlation between PEP levels and the dosage of progesterone used in therapy (r = 0.07). There were no statistically significant differences in PEP values (U/ml) depending on whether any fertility drug was taken. Thus our data suggest that progesterone may only have a permissive role, with some other factor(s) controlling the actual rise and fall of PEP.