Severe Maternal Morbidity and Infant Mortality in Canada

Abstract

BACKGROUND: Severe maternal morbidity (SMM) comprises an array of conditions and procedures denoting an acutely life-threatening pregnancy-related condition. SMM may further compromise fetal well-being. Empirical data are lacking about the relation between SMM and infant mortality.METHODS: This population-based cohort study included 1 892 857 singleton births between 2002 and 2017 in Ontario, Canada, within a universal health care system. The exposure was SMM as an overall construct arising from 23 weeks' gestation up to 42 days after the index delivery. The primary outcome was infant mortality from birth to 365 days. Multivariable modified Poisson regression generated relative risks and 95% confidence intervals (CIs), adjusted for maternal age, income, rurality, world region of origin, diabetes mellitus, and chronic hypertension.RESULTS: Infant mortality occurred among 174 of 19 587 live births with SMM (8.9 per 1000) vs 5289 of 1 865 791 live births without SMM (2.8 per 1000) (an adjusted relative risk of 2.93 [95% CI 2.51-3.41]). Of 19 587 pregnancies with SMM, 4523 (23.1%) had sepsis. Relative to births without SMM, the adjusted odds ratio for infant death from sepsis was 1.95 (95% CI 1.10-3.45) if SMM occurred without maternal sepsis and 6.36 (95% CI 3.50-11.55) if SMM included sepsis.CONCLUSIONS: SMM confers a higher risk of infant death. There is also coupling tendency (concurrent event of interest) between SMM with sepsis and infant death from sepsis. Identification of preventable SMM indicators, as well as the development of strategies to limit their onset or progression, may reduce infant mortality.WHAT'S KNOWN ON THIS SUBJECT: Severe maternal morbidity (SMM) comprises life-threatening pregnancy conditions and has risen over time in North America and Europe. As a consequence of SMM, the unborn fetus can be exposed to an adverse intrauterine environment, whether antepartum or intrapartum.WHAT THIS STUDY ADDS: In this population-based cohort study of 1.9 million maternal-infant pairs in Ontario, Canada, SMM was associated with a nearly 3 times higher risk of infant death. A coupling tendency was also seen between sepsis-related SMM and sepsis-related infant death.

Associations Between State-Level Severe Maternal Morbidity and Other Perinatal Indicators

“…To assess the validity and comparability of state-level SMM rates, we examined state-level associations between SMM and other perinatal indicators that may contribute to (eg, prepregnancy hypertension, diabetes, and obesity and low-risk cesarean delivery), coincide with (eg, preterm birth), or result from (eg, maternal and infant mortality) SMM. 4 , 5 , 6 …”

Perinatal Risks of Neonatal and Infant Mortalities in a Sub-provincial Region of China: A Livebirth Population-based Cohort Study

“…Our previous studies also demonstrated that high-risk pregnancy had an ambiguous association with perinatal mortality [ 12 , 14 ]. Even in well developed countries, severe maternal morbidities conferred increased risks of infant mortality [RR 2.93 (2.51, 3.41)] [ 37 ]. In-depth analyses are needed to explore the severity of maternal morbidities in relation to infant outcome in resource-limited, evolving regions and countries.…”

The effect of severe maternal morbidity on infant costs and lengths of stay

“…This study builds upon the sparse existing evidence that SMM is associated with infant health. One previous study of this relationship found associations between SMM and infant mortality and sepsis ( 4 ). This study used the standard CDC definition of SMM, which includes maternal readmissions up to 42 days after delivery, while our study restricted SMM to those cases identified during the delivery hospitalization in order to focus on infant outcomes.…”

“…However, there are currently little data on the effects of SMM on infant outcomes. Our literature search only identified one prior study that directly examined the association between SMM and infant health ( 4 ). The researchers used all births in Ontario from 2002 to 2017 and found that CDC-defined SMM was associated increased infant mortality and sepsis.…”