Disturbances of the endometrium in the luteal phase of cycles stimulated for in vitro fertilization and of normal cycles treated with vaginal progesterone.

Thirty-nine cycles of primarily (n = 32) and secondarily (n = 7) tubal infertile women were studied to evaluate the state of the luteal endometrium in women undergoing In Vitro Fertilization (IVF) without embryo transfer and in women in the normal unstimulated luteal phase with and without vaginal progesterone supplementation. One to four endometrial biopsies were performed in the luteal phase. Serum progesterone (P) and estradiol (E2) as well as the endometrial thickness were estimated on the same days. In groups stimulated for IVF, serum progesterone and estradiol levels were significantly higher (P < 0.01) compared to the control group. The endometrium was significantly thicker and grew more rapidly when cycles were stimulated, but the endometrial thickness did not correlate with endometrial maturation as assessed by histology. The endometrium was disturbed in a major part of the biopsies in all stimulated groups. Progesterone support had no beneficial effect. In women with unstimulated cycles, vaginal progesterone support caused mainly delayed gland maturation: the higher the dose of vaginal progesterone, the sooner the pathological changes in the endometrium were seen. With regard to endometrial histology, vaginal progesterone treatment in the luteal phase of IVF patients may not be advantageous.