Lifestyle Intervention in Obese Women with PCOS Undergoing Fertility Treatment
Overview
This randomized controlled trial evaluated a 6-month lifestyle intervention followed by fertility treatment in obese women with infertility, including those with PCOS. The intervention led to significant weight loss and increased natural pregnancy rates but did not significantly improve live-birth rates within 18 months compared to usual care.
Background
Infertility affects 10% to 15% of Canadian couples, with PCOS being a leading cause of anovulation-related infertility. Obesity exacerbates PCOS symptoms and independently reduces fertility, with higher BMI linked to lower conception rates. Prepregnancy obesity also increases risks of adverse pregnancy outcomes and long-term health issues in offspring. Guidelines recommend weight loss before conception to improve fertility and pregnancy outcomes, yet lifestyle interventions are not routinely integrated into fertility care due to limited trial evidence.
Data Highlights
Outcome
Intervention Group (IG)
Control Group (CG)
Risk Ratio (95% CI)
Weight loss at 6 months (%)
-3.21 ± 4.73
-0.40 ± 3.66
P = .003
Waist circumference change (cm)
-2.62 ± 4.46
-0.23 ± 3.81
P = .01
Live-birth rate within 18 months (%)
44.4 (n=63)
35.9 (n=64)
1.24 (0.81-1.90)
Clinical pregnancy rate (%)
52.4
37.5
1.40 (0.94-2.07)
Natural pregnancy rate (%)
27.0
12.5
2.16 (1.01-4.64)
Key Findings
The lifestyle intervention group achieved significantly greater weight loss and reduction in waist circumference after 6 months compared to controls.
Live-birth rates within 18 months were higher in the intervention group (44.4%) than controls (35.9%) but did not reach statistical significance.
Clinical pregnancy rates were higher in the intervention group (52.4%) versus controls (37.5%), with a trend toward significance.
Natural pregnancy rates were significantly increased in the intervention group (27.0%) compared to controls (12.5%), suggesting improved fertility without assisted reproduction.
The intervention consisted of individual dietician and kinesiologist follow-up plus group sessions prior to fertility treatment.
Women with PCOS and obesity were included, with a lower BMI threshold (≥27 kg/m2) recognizing their metabolic risk.
Clinical Implications
Implementing structured lifestyle interventions before and during fertility treatment can promote weight loss and increase natural conception rates in obese women with infertility, including those with PCOS. This approach may reduce reliance on costly assisted reproductive technologies. Clinicians should consider integrating multidisciplinary lifestyle support into fertility care pathways for this population.
Conclusion
A 6-month lifestyle intervention preceding fertility treatment improved weight and natural pregnancy rates but did not significantly increase live-birth rates within 18 months. These findings support lifestyle modification as a valuable component of fertility management in obese women with PCOS.
References
Obesity-Fertility RCT -- Preconception and Ongoing Lifestyle Modifications in Overweight or Obese Women with PCOS Undergoing Fertility Treatment
Patients with greater frailty showed larger improvements in health-related quality of life, while cardiovascular treatment effects did not differ significantly across frailty categories.
