Two researchers looked into whether tainted water in Flint, Michigan, had any effect on the city's fertility rate, and the resulting data led them to a chilling assessment: "This represents a couple hundred fewer children born that otherwise would have been," says David Slusky of Kansas University in a release. The working paper, which hasn't been peer reviewed, found that fertility rates in Flint dropped 12% and fetal death rates rose by a "horrifyingly large" 58% after the city switched to the Flint River as its source of public water in 2014. (Fetal deaths refer to miscarriages after 20 weeks, explains Michigan Radio.) The switch led to tap water with elevated levels of lead. Specifically, the paper found that "between 198 and 276 more children would have been born had Flint not enacted the switch in water," per the Washington Post.
The researchers compared the numbers in Flint to other cities in Michigan, including Detroit, and found that it was the only city with such numbers during this period. They also found that babies who were born in Flint during the study period had lower birth weights and were born slightly earlier than elsewhere in the state, reports the Detroit Free Press. Flint made the switch in water supply in April 2014, and state officials didn't acknowledge the problem until September 2015. The researchers examined Google searches (for, say, "lead and water") and concluded that residents were unaware of the issue during that period. They continued drinking and using the water, the general result being fewer pregnancies and unhealthier fetuses among those who did conceive, say the researchers.