RESUMO
OBJECTIVE: To study the relation of dietary phytoestrogens intake and clinical outcomes of women undergoing infertility treatment with the use of assisted reproductive technology (ART). DESIGN: Prospective cohort study. SETTING: Fertility center. PATIENT(S): A total of 315 women who collectively underwent 520 ART cycles from 2007 to 2013. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Implantation, clinical pregnancy, and live birth rates per initiated cycle. RESULT(S): Soy isoflavones intake was positively related to live birth rates in ART. Compared with women who did not consume soy isoflavones, the multivariable-adjusted odds ratios of live birth (95% confidence interval) for women in increasing categories of soy isoflavones intake were 1.32 (0.76-2.27) for women consuming 0.54-2.63 mg/d, 1.87 (1.12-3.14) for women consuming 2.64-7.55 mg/d, and 1.77 (1.03-3.03) for women consuming 7.56-27.89 mg/d. CONCLUSION(S): Dietary soy intake was positively related to the probability of having a live birth during infertility treatment with ART.