Purpose: To explore the prevalence, predictor of clinical pregnancy and possible aetiology of poor ovarian response (POR) in in vitro fertilization-embryo transfer (IVF-ET) in Chinese.
Methods: A total of 4,600 retrieval oocyte cycles were finished between July 1, 2004 and April 30, 2006. Poor ovarian responses were observed in 426 patients of 472 cycles undergoing IVF, which were selected on the same retrieve oocyte day as the control group. The outcome of IVF-ET and the common markers of ovarian reserve were compared.
Results: The patients had previous ovarian surgery in 64 cycles of 472 poor ovarian response cycles. The group with poor ovarian response has significant differences in comparison with the control group in age (36.6 +/- 4.2 vs 33.3 +/- 4.04), ovarian surgeries (13.6 vs 2.8%), dose of gonadotrophin (58.5 +/- 15.8 vs 40.6 +/- 17.0), fertilization rate (71.5 vs 86%) and pregnancy rate (14.8 vs 36.7%). In the group with poor ovarian responses, clinical pregnancy rate declined significantly in women aged >40 years than in those aged < or = 40 years (2.8 vs 18.5%, P < 0.001). The age, basal serum follicle stimulating hormone (FSH), basal serum luteinizing hormone (LH), basal oestradiol (E2) concentrations, FSH to LH ratio and the antral follicle count (AFC) are the common markers of ovarian reserve in our center. We found that there were significant differences in age, basal FSH, FSH-to-LH ratio and the antral follicle count. But no statistical significant differences were observed in basal oestradiol concentration and basal serum LH when comparing the two groups. Binary logistic regression analysis was used to study the relation among age, FSH, LH, E2, AFC and clinical pregnancy, and the age (odds ratio, 0.863; 95% confidence interval, 0.805-0.925; p = 0.000) was the only variable selected.
Conclusion: Our data show that the prevalence of poor ovarian response in Chinese is 11.9%. Previous ovarian surgery is associated with poor ovarian responses. The pregnancy rate of women with poor ovarian response is low in IVF-ET, especially the decline in clinical pregnancy rate of women aged >40 years became accelerated. Correct identification of those who are at risk for POR prior to stimulation is helpful in tailoring the best stimulation protocol to individual patients. Chronological age significantly improved the prediction of clinical pregnancy of poor ovarian responders.