Predictive value of age-specific FSH levels for IVF-ET outcome in women with normal ovarian function

BACKGROUND Most of infertile women with normal follicle stimulating hormone (FSH) levels and antral follicle count (AFC) at day 2-3 of the period, but poor IVF outcomes may occur when use of routine controlled ovarian stimulation. This paper is to evaluate the predictive value of age-specific FSH levels for IVF-ET outcomes in women with normal ovarian function. METHODS A total of 1287 women undergoing their first IVF cycles were enrolled in this retrospective study. The FSH levels and AFC of all of the women were within normal ranges (FSH ≤ 12 IU/L;AFC ≥ 5). The patients were grouped by age (younger: < 33 years, medium-aged:33-37years and older:38-41years), and within each age group, the patients were subdivided by the upper limit of the 95 % confidence interval (CI) for mean FSH levels. Patients with FSH levels equal to or greater than the upper 95 % CI of FSH in each age group were included into a premature ovarian aging (POA) subgroup (younger:FSH ≥ 7.84, medium-aged: ≥8.12 and older: FSH ≥ 8.47),the remaining patients in each age group were included into a control subgroup. The outcomes of IVF-ET were compared between the POA subgroup and the control subgroup in each age group. RESULTS In each age group, the total dose of gonadotropin(Gn) in the POA subgroups were significantly higher than those of the corresponding control subgroups. In the younger and medium-aged groups, women in the POA subgroups had significantly lower oocyte yields, frozen embryos, and higher rates of poor ovarian response(POR) than those in the corresponding control subgroups. When controlling for age, BMI and AFC, the multiple logistic regression analysis indicated the following: In each age group, the total dose of Gn was significantly correlated with POA; the oocyte yield was significantly related to POA only in the younger group; and in the whole age groups, the incidence of POR in the POA group was 2.719 times greater than in the control group (OR = 2.719, 95 % CI [1.598-4.625], P < 0.001). CONCLUSION Basal FSH levels combined with age (age-specific FSH levels) can be used as a more accurate marker for the ovarian response in women with normal ovarian reserves undergoing IVF-ET, particularly in women ≤37 years old.