A new study has found that when a mother dies during or shortly after pregnancy, her infant faces a sharply increased risk of death or hospitalization within the first year of life. The findings, published on September 25 in Obstetrics & Gynecology, highlight the profound connection between maternal and infant health outcomes.

The research, led by Dr. Eugene Declercq of Boston University, analyzed data from more than 1.6 million live births in Massachusetts between 1999 and 2020. The study aimed to explore how pregnancy-associated deaths and severe maternal complications affect infants’ survival and long-term well-being.

Over the two-decade study period, 474 pregnancy-associated deaths were identified. The highest mortality rates were observed among women aged 40 years and older, non-Hispanic Black women, those with public insurance, and mothers with four or more previous births. Death ratios were particularly elevated among women who had opioid-related hospital encounters or preexisting health conditions before pregnancy.

The data revealed striking differences in infant survival. When a mother died during or after pregnancy, the infant mortality rate was 55 deaths per 1,000 live births, compared to just 4 per 1,000 among infants whose mothers survived. The risk rose even higher — 87.9 per 1,000 live births — when the mother’s death followed a period of severe maternal morbidity.

Even when infants survived their first year, those who lost their mothers were 35% more likely to be rehospitalized, suggesting long-term vulnerabilities in both physical and emotional health.

Dr. Declercq emphasized that the findings underscore the deep interdependence between maternal and infant well-being. “If we want to protect infant health, the first step is to recognize the shared health outcomes between mothers and their infants,” he said. “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.”

The study adds to growing evidence that maternal mortality prevention is not only crucial for women’s health but also a vital strategy for reducing infant mortality and improving childhood outcomes.