During pregnancy, a woman is barraged with what foods are safe to eat and in what quantities. A new study by European researchers has found that high fish intake during pregnancy is associated with a risk of overweight and obesity in her offspring. The findings were published online on February 15 in the journal JAMA Pediatrics.
The study authors note that maternal fish intake in pregnancy has been reported to influence fetal growth; however, the extent to which fish intake affects childhood growth and obesity remains unclear. Therefore, they conducted a study to assess whether fish intake in pregnancy is associated with offspring growth and the risk of childhood overweight and obesity.
The study group comprised a total of 26,184 pregnant women and their children (singleton deliveries) from 1996 through 2011 who resided in Belgium, France, Greece, Ireland, Italy, the Netherlands, Norway, Poland, Portugal, Spain, and Massachusetts. The children were followed-up at two-year intervals until the age of six years. The investigators measured their body mass index percentiles from three months after birth to six years of age. They defined rapid infant growth as a weight gain z score greater than 0.67 from birth to two years and childhood overweight/obesity at four and six years as body mass index (BMI) in the 85th percentile or higher for age and sex. (A Z-Score is a statistical measurement of a score’s relationship to the average in a group of scores. (A Z-score of 0 means the score is the same as the average. A Z-score can also be positive or negative, indicating whether it is above or below the average and by how many standard deviations.)
The investigators found that the average fish intake during pregnancy ranged from 0.5 times/week in Belgium to 4.45 times per week in Spain. Women who consumed fish more than three times per week during pregnancy gave birth to offspring with higher BMI values from infancy through middle childhood compared to women with lower fish intake (three times per week or less). High fish intake during pregnancy (more than three times/week) was associated with increased risk of rapid infant growth (22% increased risk) and increased risk of offspring overweight/obesity at four years (14% increased risk) and six years (22% increased risk) compared to an intake of once per week or less. In addition, the effect of high fish intake during pregnancy on rapid infant growth was greater among girls (31% increased risk) than among boys (11% increased risk).
The authors concluded that high maternal fish intake during pregnancy was associated with increased risk of rapid growth in infancy and childhood obesity. They noted that their findings were compatible with the fish intake limit proposed by the US Food and Drug Administration and Environmental Protection Agency.