Female obesity adversely affects assisted reproductive technology (ART) pregnancy and live birth rates

Obesity has risen among women in the USA, including those seeking infertility treatments. In 2007, height and weight were added to the Society for Assisted Reproductive Technology Clinic Online Reporting System (SART CORS), permitting calculation of BMI (weight/height(2)) for the first time using this national dataset.

The SART CORS was used to evaluate the odds of failure to achieve a clinical intrauterine pregnancy and failure to achieve a live birth by the woman's age, BMI and oocyte source (autologous versus donor), controlling for race and ethnicity, day of embryo transfer, number of embryos transferred and infertility diagnoses. The reference population was women with normal BMI.

There were 45 163 ART embryo transfers where maternal height and weight were recorded. Increasing obesity was associated with a significant rise in failure to achieve a clinical pregnancy with the use of autologous oocytes (P< 0.0001), but no difference with the use of donor oocytes. Among women using autologous oocytes who did conceive, failure to achieve a live birth increased with increasing obesity, to a greater extent among women <35 years of age.

Higher BMI is associated with an increased failure to achieve a clinical intrauterine gestation; this risk was overcome with the use of donor oocytes. Failure to achieve a live birth increases with higher BMI, significantly with the use of autologous oocytes (P< 0.0001), and to a greater extent among women <35 years of age (P< 0.0001).