Mothers who have high levels of DDE in their blood usually find their babies grow rapidly in the first six months and by 14 months develop a high body index.
DDE, an endocrine disrupter, is a by-product of the pesticide DDT.
Scientists based in Barcelona, Spain examined data collected between 2004 and 2006 on a representative sample of 518 Spanish women in their first trimester of pregnancy. Among babies whose mothers were normal weight pre-pregnancy, those babies whose mothers had DDE levels in the top 75 percent of exposure were twice as likely to grow rapidly during their first 6 months as babies whose mothers had the lowest DDE levels. Infants in the top 50 percent of exposure were three times more likely to have high BMI scores at 14 months. The researchers did not observe an association between DDE and weight for babies of mothers who were overweight before pregnancy.
Two other human studies have shown an association between prenatal DDE exposure and obesity later in life.
Laboratory studies have suggested that "exposure to chemicals with endocrine-disrupting properties might promote shifts in appetite regulation, but may also promote obesity through metabolic changes," report lead author and epidemiologist Michelle A. Mendez, of the Centre for Research in Environmental Epidemiology, and her colleagues said.
Only 14 percent of all the children had a BMI exceeding the 85th percentile, but rapid growers of both normal-weight and overweight mothers were five times more likely than other babies to have a high BMI at 14 months.
The study has been published online October 5 ahead of print in the peer-reviewed journal Environmental Health Perspectives (EHP).