MARQUETTE – The proportion of low birth weight infants in the state has shown a slight but steady upward trend, rising from 8.4% between 2012 and 2014 to 9.1% between 2021 and 2023, according to the Michigan League for Public Policy.

Low birth weight infants weigh less than 5 pounds, 8 ounces, according to the league, a nonprofit research and advocacy organization.

Such infants face heightened risks of physiological and developmental delays that can hinder their growth, school readiness and long-term health development, the league said.

The five counties with the highest proportion of low birthweight newborns are Ontonagon, Wayne, Lake, Gensesee and Saginaw. Those with the lowest proportion are Gogebic, Delta, Otsego, Dickinson and Benzie counties.

According to Anne Kuhnen, the league’s Kids Count policy director, “There is a very strong correlation between preterm births and low birthweight, as babies born with fewer than 37 weeks of gestation have less time to grow and develop.”

The Michigan Kids Count program is part of a national effort to measure the well-being of children at state and local levels and use the information to develop ways to improve children’s lives.

The data on preterm births in Michigan shows a steady increase from 9.8% between 2012 and 2014 to 10.5% between 2021 and 2023.

Also, “structural racism and systemic barriers to high-quality health care play a role in low birth weight,” Kuhnen said.

“Research has shown inequities by race and ethnicity, particularly for Black infants who are more than twice as likely to be born with low birthweight as white babies,” Kuhnen said. 

Kuhen also said that “smoking, poor nutrition, poverty, stress, infections and violence can all increase the risk of low birthweight.”

The data on births with late or no prenatal care in Michigan shows a steady increase from 5.1% between 2012 and 2014 to 6.3% between 2021 and 2023.