Estradiol Production Linked to Infertility Outcomes
After age 35, threshold response to controlled ovarian hyperstimulation is lower
FRIDAY, Sept. 29 (HealthDay News) -- Women who are undergoing in vitro fertilization are more likely to succeed if they have a good estradiol response to controlled ovarian hyperstimulation, but beyond a certain threshold, high estradiol is associated with reduced likelihood of pregnancy, according to a study in the September issue of Fertility and Sterility. This threshold is lower in women 35 years and older than in younger women.
Mohamed F.M. Mitwally, M.D., of the State University of New York at Buffalo, and colleagues analyzed estradiol levels in 270 women who had undergone 324 in vitro fertilization-embryo transfer (IVF-ET) treatment cycles. The women were grouped into low, average and high estradiol production.
Estradiol and pregnancy were positively associated up to a certain level, after which there was a negative correlation. Low and high estradiol cycles resulted in significantly fewer pregnancies. The pivotal point in positive and negative IVF-ET outcomes occurred at significantly lower estradiol levels in women aged 35 years and older compared with younger women.
"Further studies are needed to define the optimum estradiol range associated with best IVF-ET outcome and the value of applying aromatase inhibitors for adjusting estradiol levels attained during controlled ovarian hyperstimulation into such optimum range," the authors conclude.