The association between early in marriage fertility pressure from in-laws’ and family planning behaviors, among married adolescent girls in Bihar and Uttar Pradesh, India

BACKGROUND: Married adolescent girls are vulnerable to risky sexual and reproductive health outcomes. We examined the association of fertility pressure from in-laws’ early in marriage with contraceptive use ever, parity, time until first birth, and couple communication about family size, among married adolescent girls. METHODS: Data were taken from a cross-sectional survey with married girls aged 15–19 years (N = 4893) collected from September 2015 to July 2016 in Bihar and Uttar Pradesh, India. Multivariable regression assessed associations between in-laws’ fertility pressure and each outcome, adjusting for sociodemographic covariates. RESULTS: We found that 1 in 5 girls experienced pressure from in-laws’ to have a child immediately after marriage. In-laws’ fertility pressure was associated with lower parity (Adj. β Coef. − 0.10, 95% CI − 0.17, − 0.37) and couple communication about family size (AOR = 1.77, 95% CI 1.39, 2.26), but not contraceptive use or time until birth. CONCLUSIONS: Our study adds to the literature identifying that in-laws’ pressure on fertility is common, affects couple communication about family size, and may be more likely for those yet to have a child, but may have little effect impeding contraceptive use in a context where such use is not normative. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12978-021-01116-9.