Preterm birth during the COVID-19 pandemic in Mexico

The COVID-19 pandemic has brought upon an unprecedented impact on population health and well-being, including the health of newborns. Infection from COVID has shown to adversely affect maternal and infant health by increasing the risk of preterm birth, low birth weight, and neonatal intensive care unit (NICU) hospitalization. Currently, there is limited evidence about COVID effects on birth outcomes in low- and middle-income countries. In this study, Faculty Associate Monica Caudillo and colleagues Andres Villarreal and Florencia Torche examine the consequences of the COVID-19 pandemic for preterm birth in Mexico, which is a middle-income country that experienced some of the highest rates of infection and mortality from COVID in the world. 

Microlevel data was drawn from birth certificates for all births in Mexico between January 2014 and December 2022. The geographic identifiers provided in the birth certificate were used to merge each record with the characteristics of the municipality of residence of the mother, including its levels of urbanization and economic deprivation. Time series models were then used to evaluate changes in preterm birth rates during the pandemic in Mexico. Trends in preterm birth were evaluated separately for the three major healthcare systems: public social security, public federal, and private. This study also aimed to evaluate whether women who chose to give birth in private institutions experienced a health advantage compared to women who received public care during the pandemic, and whether such advantage varied by women’s SES. Linear probability difference-in-differences and triple difference models were used for this analysis.

The findings from the time series models suggest that preterm births increased among women who gave birth in public hospitals but decreased among women who gave birth in private settings. The difference-in-differences models indicate that the health benefits from receiving private care were concentrated among women with higher levels of education. The reduction in preterm births among the women with higher education was in part explained by their choice of higher quality services within the private sector. The analysis from this study demonstrates how protective behaviors subject to heterogeneous socioeconomic and structural constraints may lead to unequal health outcomes during health emergencies.