ELEVATED BASAL ESTRADIOL LEVELS HAVE NO NEGATIVE PROGNOSIS IN YOUNG-WOMEN UNDERGOING ART CYCLES

The objective of this study was to determine the relationship between serum estradiol levels on day 2 of an in vitro fertilization and embry o transfer (IVF-ET) cycle and the chance of pregnancy and implantation rates according to age. Two hundred and forty-eight cycles of IVF-ET in patients treated with gonadotropin-releasing hormone analog (GnRHa) , follicle-stimulating hormone (FSH) and human menopausal gonadotropin (hMG) were divided into several groups according to the basal serum c oncentrations of estradiol (E-2): A < 25 pg/ml, B 26-50 pg/ml, C 51-75 pg/ml, D 76-100 pg/ml, E > 100 pg/ml. Furthermore, the patients were subdivided into two subgroups according to age: I, younger; and II, ol der than 35 years. Pregnancy and implantation rates were analyzed for each subgroup according to basal E2 level and age. Statistical analysi s was performed using analysis of variance, chi(2) and Fisher's test. The number(s) of cycles for each subgroup were 164 and 84 for I and II , respectively. Even though there were no significant differences amon g groups for the pregnancy rates for individual groups, there was a te ndency for a decreased rare with increasing levels of E-2 only in wome n older than 35 years of age. When pregnancy rates of all women with E -2 levels above 25 pg/ml were calculated, the differences between thos e observed in subgroup I (less than or equal to 35years) and II (>35 y ears) war significant: p = 0.02 (38.7% vs. 18.7%, respectively). When implantation rates in the same groups and subgroups were analyzed, we found that again the differences were statistically significant: p = 0 .001 (13.1% vs. 4.3% for I and II). The results of the present studies reveal that basal levels of E-2 are a marker of poor prognosis for im plantation and pregnancy in assisted reproduction (ART) cycles only in patients over the age of 35 years. These data cast doubt on the use of basal levels of E-2 to screen women below the age of 35 prior to init iating an ART cycle. In addition, high levels of basal E-2 per se may not be deleterious for reproductive efficiency in younger women, since pregnancy and implantation rates did not differ among patients younge r than 35 years old (IA to E).