THURSDAY, Oct. 9, 2025 (HealthDay News) -- A mother’s death during or after pregnancy increases the risk for the infant’s death or hospitalization, according to a study published online Sept. 25 in Obstetrics & Gynecology.Eugene Declercq, Ph.D., from Boston University in Massachusetts, and colleagues conducted a retrospective cohort study to examine the association between pregnancy-associated death or severe maternal morbidity and infant outcomes. The analysis included data from more than 1.6 million live births in Massachusetts between 1999 and 2020.The researchers identified 474 pregnancy-associated deaths, which were most common among individuals who were aged 40 years and older (49.3 per 100,000), were non-Hispanic Black (43.0 per 100,000), had public insurance (51.1 per 100,000), or had a parity of four or more (80.6 per 100,000). Among individuals experiencing severe maternal morbidity (745.3 per 100,000), the highest pregnancy-associated death ratios were seen among those who had a hospital encounter associated with opioid use (721.2 per 100,000) or a documented prepregnancy comorbidity (200.7 per 100,000). In cases of pregnancy-associated death, the infant mortality rate was 55.0 per 1,000 live births versus 4.0 when the mother survived. The infant mortality rate was 87.9 per 1,000 live births when the pregnancy-associated death followed severe maternal morbidity. Following a pregnancy-associated death, when a full-term infant survived to 1 year of age, there was a greater likelihood of rehospitalization in the first year of life (adjusted risk ratio, 1.35) versus when the mother did not die. "If we want to protect infant health, the first step is to recognize the shared health outcomes between mothers and their infants," Declercq said in a statement. "Improving women’s health is a worthy goal in itself, but this research reminds us that healthier mothers are also the foundation for protecting the health of their infants and, ultimately, their families."Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter