Does ovarian reserve affect outcomes in single ideal blastocyst transfers in women less than 40 years of age?

Purpose There is much debate whether diminished ovarian reserve is purely a quantitative issue, or if quality as determined by pregnancy potential of the ensuing oocytes is also affected. The purpose of this study was to determine whether diminished ovarian reserve, as established by one of three ways described below, affects pregnancy outcomes of women under 40 years old undergoing a single ideal blastocyst transfer. Materials and methods This was a retrospective cohort study, including 507 women undergoing an ideal quality single embryo transfer between August 2010 and March 2014. Logistic regression was used to control for age, duration of infertility, parity, body mass index, and smoking status. For analysis, women were stratified for: antral follicle counts (<= 5 vs. > 5), basal serum FSH levels (< 13 vs. >= 13 IU/L), and quartile of total FSH dose required for stimulation. Results In stratifying women by antral follicle count (AFC) <= 5 vs. > 5, the pregnancy rate (40 vs. 53%, p = 0.04), clinical pregnancy rate (29 vs. 46%, p = 0.02), and live birth rate (13 vs. 43%, p = 0.001) were superior with AFC > 5. Using FSH levels (< 13 vs. >= 13 IU/L), the pregnancy rate (50 vs. 31%, p = 0.27), clinical pregnancy rate (40 vs. 13%, p = 0.45), and live birth rate (38 vs. 13%, p = 0.48) were similar. Examining quartiles of FSH stimulation, the pregnancy rates were similar (from lowest to highest: 45, 52, 54, 41%, p = 0.13); however, clinical pregnancy rate (36, 43, 47, 25%, p = 0.003) and live birth rate (32, 38, 44, 20%, p = 0.005) were superior in lower quartiles vs. the highest quartile. Conclusion Ovarian reserve may affect embryo pregnancy potential and outcomes when measured by AFC and exogenous stimulation but not by basal FSH levels.