April 20, 2023
Pregnant women who live in cities with sugary beverage taxes are less likely to develop gestational diabetes or experience unhealthy weight, new research suggests. And their babies are less likely to be born small for their gestational age.
The study, conducted by researchers from the University of California, San Fransisco, examined the impact of sugary beverage taxes on the health of 5.3 million expectant mothers and their children from five cities that taxed sugary drinks – Philadelphia, San Francisco, Seattle, Oakland and Berkeley, California. They compared their data to pregnant women living in cities without a sugary drinks tax.
In cities with sugary beverage taxes, pregnant women were 41% less likely to develop gestational diabetes, a condition in which the body can't make enough insulin during pregnancy. Insulin is a hormone in the pancreas that allows blood sugar into the body's cells. Hormone changes and weight gain during pregnancy can cause a woman's body to use insulin less effectively than normal.
The researchers also found that pregnant women in cities with sweetened beverage taxes were 7.9% less likely to experience unhealthy weight gain and 39% less likely to give birth to small babies of gestational age. No other improvements to maternal and infant health outcomes were observed in the study, which examined data from 2013 to 2019.
"All three of these outcomes are important for health later in life, for both the mother and child," said researcher Justin White, a professor of health economics at UCSF. "If you can reduce risk at this key developmental stage, it can have long-lasting health benefits."
The benefits of a sugary drinks tax were most pronounced in Philadelphia, the study found. Researchers said this may have been due to the city taxing sugary drinks at a higher rate than others, resulting in less consumption.
Philly adopted the so-called soda tax in 2016 to fund a free pre-K program and Rebuild, the program used to fix up public parks and recreation centers.
The study found differences in the association between sugary beverage taxes and perinatal health across various racial and ethnic subgroups. The researchers said sugary drink companies target their marketing toward people of color and low-income communities, which contributes to significantly higher consumption during pregnancy among Black and Hispanic women than white women.
Research has found that Black and Hispanic women of childbearing age are about twice as likely as white women to drink sugary beverages.
The United States lags behind other affluent countries in maternal health. The U.S. maternal death rate increased by nearly 38% in 2021, with Black women continuing to face disproportionally high rates, according to a report released last by the U.S. Centers for Disease Control and Prevention.
In Philadelphia, the rate of pregnancy-related deaths was 20 per 1000,000 lives births from 2013 to 2018 – higher than the national rate of 17.4 per 100,000 live births, city data show. Black women accounted for 73% of pregnancy-related deaths, but only 43% of births.
Philadelphia also has a high rate of infant deaths. Infant deaths accounted for 55% of all child deaths in the city from 2011 to 2017, with Black babies having higher death rates than other racial groups. In 2018, the city's infant death rate was 8.1 per 1,000 live births, nearly 40% higher than the national rate of 5.8 per 1,000 live births.