Vaginal delivery of progesterone in donor oocyte therapy.

A prospective cohort study, with 345 women requiring complete progesterone replacement for a donor egg cycle, was used to compare Crinone 8% (90 mg progesterone vaginal gel) twice or once daily versus i.m. progesterone (100 mg), for endometrial development and pregnancy support. Endometrial histology, serum progesterone levels, pregnancy rates, implantation rates, and bleeding patterns were used as outcome measures. Mean serum progesterone concentrations on day 26 were 19.0 + 2.3 ng/ml for twice and 11.3+/-6.5 ng/ml for once daily Crinone, versus 65.2+/-12.5 ng/ml in the i.m. progesterone group. Endometrial histology was 'in phase' for all women in the Crinone groups and most of the i.m. group. Though eight of 42 patients on once daily Crinone had serum progesterone levels under 6 ng/ml, there was no correlation with endometrial development. Only one patient bled on once daily Crinone before the 14th day of progesterone therapy, and she went on to deliver twins. Clinical pregnancy, ongoing pregnancy, implantation, and miscarriage rates were not statistically different among any of the treatment groups. Crinone 8% administered once or twice daily appears to produce the same endometrial development and pregnancy rates as i.m. progesterone in women requiring complete progesterone replacement, and without early bleeding.