According to a report in the Irish Mail on Sunday, a mass grave has been located beside a former home for unmarried mothers and babies in County Galway. The grave is believed to contain the bodies of up to eight hundred babies, buried on the former grounds of the institution known locally as “The Home” in Tuam, north of Galway city, between 1925 and 1961
Run by the Bon Secours nuns, “The Home” housed thousands of unmarried mothers and their “illegitimate” children over those years.
In the early 20th century Ireland had really high child mortality, high TB rates and I imagine since these women were shamed by nuns and the church the babies were delivered at the house without proper medical training so many were probably deformed/premature.