Obesity in pregnant mothers may affect their son''s physical and mental development later in life, according to a study which suggests the effects in infants are comparable to the impact of lead exposure in early childhood.
The study, published in the journal BMC Pediatrics, noted that obesity in pregnant mothers is linked to lagging motor skills in preschoolers, and lower IQ in middle childhood for their sons.
As part of the study, the researchers, including those from Columbia University in the US, studied 368 mothers and their children -- both during pregnancy and when the children were 3 and 7 years of age.The families were from similar economic circumstances and neighbourhoods, the study noted.
At age 3, the researchers measured the children''s motor skills, and found that maternal obesity during pregnancy was strongly associated with lower motor skills in boys.
When they again measured the children at age 7, they found that the boys whose mothers were overweight or obese in pregnancy had scores 5 or more points lower on full-scale IQ tests, compared to boys whose mothers had been at a normal weight.
According to the researchers, such an effect was not found in girls.
"What''s striking is, even using different age-appropriate developmental assessments, we found these associations in both early and middle childhood, meaning these effects persist over time," said study co-author Elizabeth Widen from the University of Texas at Austin in the US.
"These findings aren''t meant to shame or scare anyone. We are just beginning to understand some of these interactions between mothers'' weight and the health of their babies," Widen explained.Although previous research has found links between a mother''s diet and cognitive development, the scientists said it is still not clear why obesity in pregnancy may affect a child later.They speculated that dietary and behavioral differences may be driving factors, or fetal development may be affected by processes that happen in the bodies of people with a lot of extra weight.
These factors, the researchers said, may include inflammation, metabolic stress, hormonal disruptions and high amounts of insulin and glucose.
In their analysis, the scientists said they controlled for several factors such as race and ethnicity, marital status, the mother''s education and IQ, as well as whether the children were born prematurely or exposed to environmental toxic chemicals like air pollution.
However, the study did not include details about what the pregnant mothers ate, or whether the children were breastfed.The scientists also accounted for the nurturing environment in a child''s home, specifically looking at how parents interacted with their children, and if the child was provided with books and toys.
According to the study, a nurturing home environment was found to lessen the negative effects of obesity.
While the effect on IQ was smaller in nurturing home environments, the researchers said it was still there.The researchers advised pregnant women who are obese or overweight to eat a well-balanced diet that is rich in fruits and vegetables, take a prenatal vitamin, stay active, and make sure to get enough fatty acids such as the kind found in fish oil.