RESUMO
OBJECTIVE: To determine whether once-daily dosing of Crinone 8% (90-mg progesterone vaginal gel; Serono Laboratories, Inc., Norwell, MA) is sufficient for normal endometrial development and pregnancy support. DESIGN: Prospective cohort study. SETTING: Academic medical center. PATIENT(S): Eighty-six women who required complete progesterone replacement for a donor egg cycle. INTERVENTION(S): Crinone 8% (90 mg) once daily or IM progesterone (100 mg) once daily was administered from day 15 onward. Both groups underwent an endometrial biopsy on day 26 of a mock cycle, followed by a second cycle in which ET was performed. MAIN OUTCOME MEASURE(S): Endometrial development, serum progesterone levels, pregnancy rates, implantation rates, and bleeding patterns. RESULT(S): Mean (+/-SD) serum progesterone levels on day 26 were 11.3+/-6.5 ng/mL in the Crinone group and 65.2+/-12.5 ng/mL in the IM progesterone group. At histologic examination, endometrial biopsy specimens were found to be "in phase" for 100% (42/42) of women in the Crinone group and 95.5% (42/44) of women in the IM progesterone group. Although 8 of 42 patients had serum progesterone levels of <6 ng/mL, there was no correlation with endometrial development. Only 1 patient bled before the 14th day of progesterone therapy, and she went on to be delivered of twins. Clinical pregnancy, ongoing pregnancy, implantation, and miscarriage rates were not statistically different for the Crinone and IM progesterone groups: 45.6% (21/46) versus 52.3% (23/44); 39.1% (18/46) versus 40.9% (18/44); 21.5% (34/158) versus 19% (30/158), and 14.3% (3/21) versus 22% (5/23), respectively. Power was sufficient to detect a 25% difference in clinical pregnancy rates. CONCLUSION(S): Crinone 8% administered once daily appears to produce the same endometrial development and pregnancy rates as IM progesterone in women who require complete progesterone replacement, and it does not cause early bleeding.