Progesterone profiles in luteal phase defect cycles and outcome of progesterone treatment in patients with recurrent spontaneous abortion.

The existence of luteal phase defect has been the focus of much debate, mainly because of inconsistencies in its diagnosis and management. This study was performed to compare progesterone profiles in women with luteal phase defect with those of women with normal cycles and to establish a discriminatory level of serum progesterone that may aid in the diagnosis of this condition. Compared with patients with luteal phase defect cycles, women with normal cycles produced significantly more progesterone in the luteal phase. The serum progesterone level (less than or equal to 21 nmol/L) was the optimal discriminatory level between luteal phase defect and normal cycles and provided a diagnostic test with 70% sensitivity and 71% specificity. In women with recurrent abortion, the incidence of luteal phase defect was 40%, but with treatment 81% of pregnancies were successful. The findings in this study support the existence of luteal phase defect as a clinically significant entity in recurrent first-trimester spontaneous abortion and one that can be treated successfully with the administration of progesterone. The histologic diagnosis of luteal phase defect may also be confirmed with serum progesterone.