Body Mass Index and IVF outcomes in non-obese endometriosis patients

Does higher body mass index (BMI) improve IVF outcomes among non-obese endometriosis patients?

Key Points

Highlights:

• Lower BMI is a predictive factor for severe endometriosis, which is linked with lower reproductive success even with IVF. Based on this fact, this study hypothesized that a higher BMI might improve the outcomes of IVF in non-obese endometriosis patients.
• The results, however, did not support the hypothesis – higher BMI did not enhance the outcome of IVF in these patients.

Importance:

• Understanding the effect of BMI on IVF success in women with endometriosis could change the infertility treatment approach for these patients. The revised treatment plan could include a recommendation of an ideal BMI before the IVF procedure.

What’s done here?

• A preliminary retrospective observational study in women with endometriosis as the sole cause of infertility, who underwent IVF.
• Primary outcomes measured were the number of retrieved oocytes, quality of oocytes and embryos, and the rates of ongoing pregnancies between underweight, average weight, and overweight study groups.

Key results:

• No significant differences were found in the number of retrieved oocytes, obtained embryos, and pregnancy rates between study groups.
• Increase in BMI did not affect the outcome of IVF in non-obese endometriosis patients.

Limitations of the study:

• The retrospective design of the study with patients receiving a differential assessment of the stage of the disease, or different IVF or surgical approaches.
• BMI might not be the only indicator of weight-related reproductive issues.
• The inclusion criteria used in the study was strict, resulting in a smaller study group.

Lay Summary

Endometriosis and body mass index (BMI) are inversely related, meaning obese women are at a lower risk of developing endometriosis. Similarly, women with lower BMI are considered high risk for severe types of endometriosis. The severity of endometriosis brings about lower reproductive chances. All of these facts indicate higher BMI among women with endometriosis may lead to an increased reproductive outcome in these patients.

Garalejic et al. investigated the effect of BMI on in vitro fertilization (IVF) outcomes in endometriosis patients who are non-obese (BMI<30) in a total of 156 patients. The subjects were divided into underweight, average weight, and overweight study groups; and the number of retrieved oocytes (immature eggs) and embryos, as well as the rates of pregnancies, were compared between these groups. The results indicated no significant differences in any of the primary outcomes studied – the number of oocytes, embryos, rates of pregnancies. Although the preliminary results obtained in this study did not support the hypothesis that higher BMI may increase the chances of successful IVF outcomes, future studies might provide further support for this theory. The retrospective nature of the current research and the stringent inclusion criteria for study subjects resulting in smaller study populations were the main shortcomings of this study. Future prospective studies with a large number of patients with endometriosis could better address the question at hand and may prove a correlation between higher BMI and IVF success in endometriosis patients. If this were true, achievement of optimal BMI before IVF could be recommended to the endometriosis patients undergoing IVF to achieve higher pregnancy rates.

Research Source: https://www.ncbi.nlm.nih.gov/pubmed/29145852