Fertility rates decreased by 12% among Flint women, and fetal death rates increased by 58%, after April 2014, according to research by assistant professors and health economists David Slusky at Kansas University and Daniel Grossman at West Virginia University. The pair examined vital statistics data for Flint and the rest of the state of Michigan from 2008 to 2015, zoomed down to the census-tract level. That post-April 2014 time period is significant, because that's when — in an effort to save money — the city of Flint switched from water supplied by the city of Detroit to using the Flint River as a drinking water source, without adding needed anti-corrosives to the water. Lead levels in drinking water supplies spiked as a result. Babies born in Flint were also nearly 150 grams lighter than in other areas, were born a half-week earlier and gained 5 grams per week less than babies in other areas examined over the time period.