THE EFFECT OF PROGESTERONE ADMINISTRATION IN THE FOLLICULAR PHASE OF AN ARTIFICIAL CYCLE ON ENDOMETRIAL MORPHOLOGY - A MODEL OF PREMATURE LUTEINIZATION

Objective: To evaluate the effect of premature P administration on art ificially prepared endometrium in women with ovarian failure. Design: To mimic premature luteinization, patients with ovarian failure were t reated with continuous estrogen and episodic P during the follicular p hase of artificial cycles. Setting: In vitro fertilization unit at a u niversity hospital. Patients: The study group included 16 patients wit h ovarian failure who were randomly divided into two groups. Group A ( 8 patients) was treated by episodic P administration during the artifi cial follicular phase on days 2 and 7 (12.5 mg of P in oil IM), and in group B (8 patients), P (6.25 mg) was added on days 3, 4, and 5. Anot her 16 patients (group C), age matched to the study group, were arbitr arily allocated to serve as controls and had standard preparatory cycl es without P supplementation in the follicular phase. Serum E, and P l evels and endometrial biopsies were taken on days 14 and 26. Results: Serum E, levels were comparable between the study group (group A + B) and controls on both days 14 and 26. Although serum P levels did not d iffer between the groups on day 26, it was higher in the follicular ph ase of the study group than in the controls (1.9 +/- 4.0 and 0.2 +/- 0 .1 ng/mL, respectively). In the study group, 8 of 16 patients demonstr ated early secretory changes in the late follicular phase biopsies, an d 9 of 16 women developed stromal-glandular discrepancy in the late lu teal phase. This differed significantly from the controls in which onl y one late luteal biopsy was out of phase. Conclusions: Episodic surge s of P during the follicular phase may result in impaired endometrial development that cannot be corrected by P supplementation during the l uteal phase. This unique model provides evidence for the potential det rimental effect of premature P secretion in the follicular phase on en dometrial function.