A 14-fold increase in infant mortality rates among babies whose mothers experienced a pregnancy-related death vs those whose mothers survived pregnancy and postpartum was reported in Massachusetts during a study published in Obstetrics & Gynecology.1
The study led by Boston University School of Public Health (BUSPH) researchers is the first in decades to provide insight into the correlation between maternal death and infant health in the United States. According to the researchers, the data highlights a need to increase women’s health support.1
Key takeaways:
- Infants whose mothers died during or after pregnancy had a 14-fold higher mortality rate compared to those whose mothers survived.
- The study analyzed over 1.6 million live births in Massachusetts between 1999 and 2020.
- Opioid use and pregnancy comorbidities were major contributors to maternal deaths.
- Surviving infants of deceased mothers were 35% more likely to be rehospitalized within their first year.
- Researchers emphasized the need for integrated maternal-infant health care and expanded access to opioid use disorder treatment during pregnancy.
“If we want to protect infant health, the first step is to recognize the shared health outcomes between mothers and their infants,” said Eugene Declercq, PhD, lead study author and professor of community health sciences at BUSPH.1
Linking maternal mortality and infant health outcomes
The retrospective cohort study was conducted to determine the link between pregnancy-associated death or severe maternal morbidity and infant outcomes.2 Massachusetts statewide data between 1999 and 2021 was obtained for the analysis, including hospital records linked to maternal and infant death records.
Pregnancy-associated death was defined as mortality in the intrapartum through 1-year postpartum period. Severe maternal morbidity and pregnancy-associated death after severe maternal morbidity were also considered exposures.2
Infant death within 1 year of birth was reported as the primary outcome. Hospitalization in the first year of life was also reported for infants who survived. Correlations between exposures and outcomes were estimated through bivariate and robust Poisson regression analyses.2
Disparities in pregnancy-related death ratios
There were 474 pregnancy-related mortalities across 1,617,054 live births from 1999 to 2020 in Massachusetts. The most significant death ratios were reported in:
- Patients aged at least 40 years at 49.3 per 100,000 live births
- Non-Hispanic Black patients at 43 per 100,000 live births
- Patients with public insurance at 51.1 per 100,000 live births
- Patients with a parity of 4 or more at 80.6 per 100,000 live births
The greatest pregnancy-related death ratios were reported for mothers with a hospital encounter linked to opioid use or a documented pregnancy comorbidity vs other severe maternal morbidity, at 721.2 and 200.7 per 100,000 live births, respectively. Severe maternal morbidity was reported in 745.3 per 100,000 cases.2
Infant mortality and rehospitalization
In infants of mothers with a pregnancy-related death, the mortality rate was 55 per 1000 live births, vs 4 per 1000 live births in those whose mothers survived. Additionally, this rate rose to 87.9 per 1000 live births when pregnancy-associated death was preceded by severe maternal morbidity.2
Infants surviving the first year of life following a pregnancy-related death were 35% more likely to experience rehospitalization within 1 year of birth compared to those whose mothers did not die. Overall, the data highlighted an association of pregnancy-related death with infant mortality and worsened health.2
“Our extensive work using longitudinally linked data in the Pregnancy-to-Early Life database in Massachusetts has importantly shown that there are missed opportunities to identify and follow mothers and their children for adverse health outcomes,” said Howard J. Cabral, PhD, study coauthor and professor of biostatistics at BUSPH.1
Opioid use identified as a major risk factor
While opioid use was highlighted as a significant driver of pregnancy-associated death, data has indicated that buprenorphine may be administered to pregnant patients to treat opioid use disorder (OUD).3 This data was discussed by Baher Mankabady, MD, Senior Vice President at Indivior, in an interview with Contemporary OB/GYN.
According to Mankabady, OUD poses a severe public health threat, but treatment with buprenorphine has been linked to reduced odds of adverse outcomes such as preterm birth and low birth weight. This highlights health benefits from recommending buprenorphine through medical guidelines.3
“When patients with OUD, when they get pregnant, this is the time that they will be open for treatment and engagement with health care providers,” said Mankabady. “This study offers promising evidence that SUBLOCADE can be safely considered during treatment of OUD during pregnancy.”3
