Complete down-regulation is not mandatory for good assisted reproductive treatment cycle outcomes

To determine the implications and predictive value of estradiol concentrations following pituitary down-regulation with gonadotrophin releasing hormone agonists in women undergoing controlled ovarian hyperstimulation for assisted reproductive technology.

A total of 277 patients undergoing ovarian hyperstimulation for intracytoplasmic sperm injection (ICSI) were enrolled into the study and the patients were divided into four groups according to estradiol levels on the initial day of stimulation of which group-A consisted of the patients who had < or =25 pg/ml (n=90), group-B with levels between 26 and 50 pg/ml (n=104), group-C with levels between 51 and 75 pg/ml (n=67) and group-D with levels > or =76-90 pg/ml (n=16) and the results were compared. The primary outcome measures included ovarian response and the clinical pregnancy rates.

The clinical pregnancy rates in groups-A, B, C and D were 33.3% (30/90), 26.0% (27/104), 35.8% (24/67), and 25.0% (4/16), respectively, and there was no statistically significant difference (P=0.482). The mean number of oocytes retrieved in groups were (9.7+/-5.8, 10.3+/-6.5, 11.0+/-6.8, and 12.1+/-6.6), respectively (P=0.453) and the fertilization rates in groups-A, B, C and D were found to be similar (75, 80, 73 and 79%, respectively; P=0.658).

Complete and deep desensitization obviously seems not to be mandatory for successful stimulation in assisted reproductive technology cycles.