Abstract
BACKGROUND: Effective family planning interventions may have inadvertent effects on births of girls given son preference in India. We conducted 36 and 48-month follow-ups to our CHARM2 family planning study to determine long-term intervention effects on births and sex of children. METHODS: Our non-blinded two-armed cluster RCT randomized young married couples (N = 1201 couples) from 20 geographic clusters (60-61 couples per cluster) into either the CHARM2 intervention or control (referral to local care) condition. CHARM2 offers 5-session gender-synchronized family planning and gender equity counseling delivered by trained local medical providers. Data were collected at baseline in September 2018-June 2019 and then follow-ups at 9, 18, 36 and 48 months, up to September 2023. We retained 88 %-91 % of women across follow-ups with no difference in retention by treatment group. We used adjusted mixed-effects logistic regression models examining sex composition of births at each follow-up and over the total 48-month follow-up to assess differences in all births of boys and girls by treatment group. We adjusted for treatment condition, cluster, and relevant demographics in adjusted models. RESULTS: We saw no treatment effects on total births or boy births, but lower likelihood of a girl birth was seen at 9-month follow-up and for the total 48-month follow-up period. We found at 9-month follow-up a girl birth was less likely for intervention compared with control participants (7.1 % vs. 10.3 %, respectively, p = 0.06), and the male to female sex ratio of births born between baseline and 9-month follow-up was also significantly higher for intervention vs. comparison participants (1.50 [95 % CI 1.00-2.26] vs. 0.83 [95 % CI 0.56-1.21], p = 0.04). We conducted a sensitivity analysis to determine treatment effects on boy births and girl births over the 48-month follow-up and again found no effects on boy births, but a significantly lower likelihood of a girl birth for the intervention group (22 % vs 29 %, p = 0.03). CONCLUSION: The CHARM2 family planning intervention, previously demonstrating significant effects on contraceptive use and women's reproductive agency in rural India, resulted in lower likelihood of girl births over time, suggesting that family planning programs can contribute to sex ratio imbalances if broader social changes eliminating son preference and improving value of a girl child do not occur. FUNDING: National Institutes of Health, Grant R01HD084453 Bill and Melinda Gates Foundation. INV002967. The funders had no role in the design and conduct of the study, collection, management, analysis, and interpretation of the data; or preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication. [ClinicalTrials.gov Identifier: NCT03514914.].