As promised, each Thursday, we will now offer you a piece of educational, science, or research related information. The purpose of our #ThursdayThoughts post is to share with you fact-based content that can enlighten and assist you on your fertility journey. Enjoy our post! Helping to Create New Beginnings….
Body Mass Index and Infertility
Obesity and its correlation to infertility have been consistently mentioned in the literature. Most recent data suggest that about 36.5% of reductive-aged women in US are obese and 26.3% are overweight (Whynott et al., 2021). With obesity being so prevalent in the current reproductive population, it is reasonable to investigate how it can impact conception and the success rate of infertility treatments. Obesity is known to be associated with ovulatory dysfunction (irregular menses or no menses), decreased spontaneous pregnancy rate, and increased time to pregnancy (Hornstein et al., 2021). Complications during pregnancies have been noted including miscarriage, recurrent pregnancy loss, preeclampsia, gestational diabetes and preterm birth. Studies have also recognized decrease in live birth rates in relation to increased BMI (Eaton, 2021).
However, there are currently not enough data to suggest that we should be withholding or delaying infertility treatments due to high BMI. Whynott et al. (2021) studied the impact of obesity and its impact on intrauterine insemination (IUI) success rates. After evaluating 3,217 IUI cycles in this cohort study, the authors concluded that live birth rates did not significantly differ between women with normal BMI and obesity. They also noted that the rate of biochemical pregnancy was higher in women with obesity. Eaton (2021) reviewed this study and suggested that impact of BMI may not be as significant because ovarian dysfunction-which is a common infertility factor associated with obesity-is easily treated with ovulation induction medications.
Given that obesity is still associated with multiple complications in pregnancy, it is important to understand the risks. A consultation with a fertility specialist is recommended for discussing individualized testing and treatment.
Eaton JL. Overweight and obesity among women undergoing intrauterine insemination: Does body mass index matter? Fertil Steril. 2021 Jan;115(1):91.
Hornstein, M., et al. (2021). Optimizing natural fertility in couples planning pregnancy. UpToDate. https://www.uptodate.com/contents/optimizing-natural-fertility-in-couples-planning-pregnancy
Whynott RM, et al. Effect of body mass index on intrauterine insemination cycle success. Fertil Steril. 2021 Jan;115(1):221-228