Maternal obesity and glucose intolerance during pregnancy among Mexican-Americans.

Low birthweight is uncommon among Mexican-American infants, despite the substantial proportion of mothers who live in poverty. This apparent paradox has generated studies of factors protecting fetal growth, but may have masked other important health problems in the Mexican-American community. Obesity, impaired glucose tolerance and diabetes are common among Mexican-American women of childbearing age and during pregnancy. Prevalence of these conditions is two to four times higher in Mexican-American than in non-Hispanic white women. As obesity and glucose intolerance during pregnancy are associated with fetal overgrowth and increased risk of subsequent obesity and type 2 diabetes in mother and child, the adequacy of birthweight as a measure of maternal and infant risk may be obscured in populations with a high prevalence of these conditions. Their possible contribution to the increasing incidence of obesity and type 2 diabetes in Mexican-American children, adolescents and young adults has not been examined. Appropriate preconception, prenatal and follow-up care may identify high-risk women, improve weight and metabolic status and reduce the severity and impact of diabetes and its complications. However, late or no prenatal care is common among Mexican-American women and the frequency of follow-up care is unknown. As low birthweight is a major public health indicator of maternal and neonatal health, perceived 'good birth outcomes' have reduced health policy, programme and research attention to Mexican-American mothers and infants. Studies of the impact of obesity and glucose intolerance during pregnancy on the birthweights of Mexican-American infants should be undertaken, along with systematic assessment of the subsequent health status and preventive health-care needs of women and children in this population.