Between 1997 and 1999, researchers at the University of Wisconsin-Madison conducted a pilot study to identify and assess why immigrant mothers (primarily those from Mexico) living in the United States have better pregnancy outcomes than native-born Hispanic mothers.
Despite being socially and economically disadvantaged, Mexican-American mothers have healthier babies (e.g., higher birth weight, less pre-maturity and fewer infant deaths) than do native-born Hispanic women. Health experts need more data in order to understand this "paradox."
The researchers concluded that the foreign-born Mexican-American mothers studied had better pregnancy outcomes than native-born Hispanic mothers because:
They found no differences in outcomes related to "Americanization" (language use and duration of residency in the United States).