Weight Loss Prior to IVF May Enhance Pregnancy Rates

A recent systematic review and meta-analysis of randomized controlled trials (RCTs) has indicated that weight loss interventions prior to in vitro fertilization (IVF) could potentially enhance the likelihood of achieving pregnancy. This research, published in the Annals of Internal Medicine, particularly highlights the benefits of weight loss for women pursuing assisted reproductive technologies.

The study was conducted by researchers at the University of Oxford, who meticulously analyzed data from 12 RCTs involving 1,921 female participants. These trials, which were conducted from 1980 until May 27, 2025, focused on women aged 18 and older with a body mass index (BMI) of 27 kg/m² or higher, all of whom were seeking IVF, with or without intracytoplasmic sperm injection for infertility.

The primary outcomes measured included rates of unassisted pregnancies, IVF-induced pregnancies, overall pregnancies (unassisted plus treatment-induced), and the delivery of live infants. The participants, typically women in their early 30s, had a median baseline BMI of 33.6 kg/m².

Among the weight loss strategies examined were low-energy diets, exercise programs combined with dietary advice, and pharmacological treatments alongside lifestyle modifications. The findings revealed that those who engaged in weight loss interventions experienced higher rates of unassisted pregnancies. However, the impact on IVF treatment-induced pregnancies remained ambiguous, and the relationship between weight loss and live birth rates was uncertain. Notably, there was moderate confidence in the absence of a link between weight loss and pregnancy loss.

These results suggest that weight loss prior to IVF can lead to increased overall pregnancy rates, primarily through enhanced unassisted conception. Nonetheless, the researchers emphasized the necessity for further high-quality clinical trials to explore different weight loss strategies, particularly those that are most effective at achieving significant weight reductions, such as total diet replacement programs.

For more details, refer to the study titled The Effect of Weight Loss Before In Vitro Fertilization on Reproductive Outcomes in Women With Obesity: A Systematic Review and Meta-analysis, published in the Annals of Internal Medicine.