Spillover Effects of Prenatal Care Coordination on Older Siblings Beyond the Mother-Infant Dyad

Pregnancy care coordination increases preventive care receipt for mothers and infants. Whether such services affect other family members' health care is unknown.

To estimate the spillover effect of maternal exposure to Wisconsin Medicaid's Prenatal Care Coordination (PNCC) program during pregnancy with a younger sibling on the preventive care receipt for an older child.

Gain-score regressions-a sibling fixed effects strategy-estimated spillover effects while controlling for unobserved family-level confounders.

Data came from a longitudinal cohort of linked Wisconsin birth records and Medicaid claims. We sampled 21,332 sibling pairs (one older; one younger) who were born during 2008-2015, who were <4 years apart in age, and whose births were Medicaid-covered. In all, 4773 (22.4%) mothers received PNCC during pregnancy with the younger sibling.

The exposure was maternal PNCC receipt during pregnancy with the younger sibling (none; any). The outcome was the older sibling's number of preventive care visits or preventive care services in the younger sibling's first year of life.

Overall, maternal exposure to PNCC during pregnancy with the younger sibling did not affect older siblings' preventive care. However, among siblings who were 3 to <4 years apart in age, there was a positive spillover on the older sibling's receipt of care by 0.26 visits (95% CI: 0.11, 0.40 visits) and by 0.34 services (95% CI: 0.12, 0.55 services).

PNCC may only have spillover effects on siblings' preventive care in selected subpopulations but not in the broader population of Wisconsin families.