Data may inform patient discussions
The current study is important because a large amount of previous research has shown an association between obesity and decreased fecundity in women and men, Mark P. Trolice, MD, of the University of Central Florida, Orlando, and director of the IVF Center in Winter Park, Fla., said in an interview.
According to the Centers for Disease Control and Prevention, the prevalence of obesity in the United States remains more than 40%, said Dr. Trolice. “Patients and physicians would benefit from clarity of obesity’s effect, if any, on reproduction,” he noted.
In contrast to the authors’ hypothesis, “the study did not find a difference in the live birth rate following up to three cycles of intrauterine insemination (IUI) between an intensive weight loss group [and] women who exercised without weight loss,” said Dr. Trolice. “Prior to this study, many reports suggested a decline in fertility with elevations in BMI, particularly during fertility treatment,” he added.
The take-home message from the current study is a that an elevated BMI, while possibly increasing the risks of metabolic disorders, did not appear to impact fecundity, he said.
The authors therefore concluded, “There is not strong evidence to recommend weight loss prior to conception in women who are obese with unexplained infertility,” Dr. Trolice said.
Regardless of the potential effect of preconception weight loss on fertility, barriers to starting a weight loss program include a woman’s eagerness to move forward with fertility treatments without waiting for weight loss, Dr. Trolice noted. “By the time a woman reaches an infertility specialist, she has been trying to conceive for at least 1 year,” he said. “At the initial consultation, these patients are anxious to undergo necessary additional diagnostic testing followed by treatment. Consequently, initiation of a weight-loss program is viewed as a delay toward the goal of family building,” he explained.
“More research is needed to demonstrate the safety of intensive weight loss preconception,” said Dr. Trolice. However, he said, “the issue of elevated BMI and increased risk of pregnancy complications remains, but this study provides important information for providers regarding counseling their patients desiring pregnancy.”
The study was supported by multiple grants from the National Institutes of Health through the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Center for Advancing Translational Sciences. Nutrisystem provided discounted coupons for food allotments in the standardized treatment group, and FitBit provided the study organizers with discounted Fitbits for activity monitoring. Lead author Dr. Legro disclosed consulting fees from InSupp, Ferring, Bayer, Abbvie and Fractyl, and research sponsorship from Guerbet and the National Institutes of Health. Dr. Trolice had no financial conflicts to disclose and serves on the Editorial Advisory Board of Ob.Gyn News.