Prenatal Opioid Exposure Tied to Higher Childhood Hospital Admissions

Children whose mothers received opioid prescriptions during pregnancy had higher rates of hospital admission than unexposed children, according to a nationwide birth cohort study from South Korea published in PLOS Medicine. The association was attenuated, but remained statistically significant, in a sibling comparison analysis.

Using National Health Insurance Service data, investigators linked mothers and children born between January 1, 2010, and December 31, 2017, and followed children for up to 14 years. Prenatal opioid exposure was defined as maternal receipt of two or more opioid prescriptions within any trimester. Of 2,928,186 children in the final cohort, 118,671 had prenatal opioid exposure. The investigators constructed propensity score (PS)-matched and sibling comparison cohorts and performed dose-dependent and time-attenuation analyses.

In the PS-matched cohort, the rate of hospital admission was 28% higher among children with prenatal opioid exposure (adjusted incidence rate ratio [aIRR], 1.28; 95% CI, 1.28-1.29). The association was attenuated in the sibling comparison cohort (aIRR, 1.08; 95% CI, 1.07-1.10), which the authors said indicates the potential influence of shared familial factors.

Admission rates increased with maternal opioid dose and prescription duration (low-dose exposure: aIRR, 1.19; high-dose exposure: aIRR, 1.40). Prenatal exposure was associated with higher admission rates for infections, oral cavity diseases, injuries/external causes, and non-infectious respiratory, gastrointestinal, and genitourinary conditions. These associations diminished with age but remained evident up to 5 years of age.

The authors noted that prescription records may not fully capture actual medication intake, that residual confounding cannot be entirely excluded, and that the observational design limits causal inference. They said the findings may inform postnatal monitoring and management strategies for children born to mothers who received opioid prescriptions during pregnancy.

Source: Kim HJ, Yim Y, Nehs CJ, et al. Maternal opioid prescriptions and subsequent risk of hospital admission in offspring in South Korea: a nationwide birth cohort study. PLoS Med. 2026;23(10):e1004829. doi:10.1371/journal.pmed.1004829