Randomized Trial of a Lifestyle Program in Obese Infertile Women

This multicentre RCT in Netherlands randomized infertile women between 18 and 39 years of age with BMI 29 or higher to 2 groups:

Methodology

1) Intervention group: 6-month lifestyle-intervention program followed by 18 months of infertility treatment.

• Goal: weight loss of 5-10% of initial body weight

• Lifestyle intervention was administered by trained nurses or dietitians, included 6 outpatient visits and 4 telephone consultations

• Lifestyle intervention method: to reduce energy intake by 600 kcal daily with the assistance of an online diet diary, while maintaining a minimum caloric intake of 1200 kcal/day; to perform at least 30 minutes of moderate-intensity physical activity 2-3 times/week, with a target level of 10,000 steps per day; motivational counseling

• Inclusion criteria: Infertile women [chronic anovulation or had unsuccessfully tried to conceive for at least 12 months]

• Exclusion criteria: severe endometriosis, premature ovarian failure, endocrinopathy (e.g., T1DM or Cushing’s syndrome), untreated preexisting hypertension, hypertension-related complications in a previous pregnancy

2) Control group: Prompt infertility treatment for 24 months

Primary outcome: Vaginal birth of a healthy singleton at term within 24 months after randomization. 

Results (Intervention vs Control group):

In the intention-to-treat analysis (dropout included),

- Mean weight loss: 4.4 kg vs 1.1 kg (p<0.001)

- Primary outcome: 27.1% vs 35.2% (p=0.06)

- Live birth: 43.9% vs 53.9% (p=0.04)

- Adverse events and complications: Not sig between groups

In the per-protocol analysis (dropout excluded),

- Primary outcome: Not sig between groups

- Live birth: Not sig between groups

Limitation

-Non-blinded

-Access to infertility treatment was only 18 months for the intervention group compared with 24 months for the control group

-Only 38% of participants reached their target weight loss; dropout rate was 21.8%

Conclusion:

6-month structured intervention program to facilitate weight loss preceding infertility treatment, as compared with prompt infertility treatment, did not improve rates of vaginal birth of healthy singletons at term during 24 months of follow-up.

Note: In RCT, intention-to-treat analysis (“analysed as randomized”) is the primary analysis as it reflects the real-life situation, maintain the initial random allocation, reduced bias estimate of treatment effects etc. 

Mutsaerts et al. N Engl J Med 2016; 374:1942-1953. DOI: 10.1056/NEJMoa1505297