Researchers from the University of Bristol and Imperial College London discovered that a mother’s high BMI during and during pregnancy is not a significant source of obesity in her children, suggesting that childhood and adolescent obesity is more likely to be caused by lifestyle factors.
Children of the 90s (also known as the Avon Longitudinal Research of Parents and Children) at the University of Bristol and Born in Bradford at Bradford Teaching Hospitals NHS Foundation Trust were utilized in the study, which was published today (1 February 2022) in BMC Medicine.
Although it is well established that a higher maternal BMI before or during pregnancy is linked to a higher BMI in children, it is unknown to what degree the mother’s weight causes juvenile obesity, or if this is caused by environmental and lifestyle variables after conception and delivery.
The University of Bristol researchers utilized a process known as Mendelian randomisation, which examines gene variation to estimate the influence of an exposure on an outcome. They looked at birthweight and BMI at ages 1 and 4 in both Children of the 90s and Born in Bradford participants, as well as BMI at ages 10 and 15 in only the Children of the 90s. They discovered a modest causal impact between mother BMI and child birth weight, but they did not detect a robust causal effect in most older age groups.
Dr. Tom Bond, Senior Research Associate at the University of Bristol, who is the lead author, explained: “We discovered that a woman’s weight at the outset of pregnancy isn’t a significant predictor of her child’s weight as a teenager. This is crucial information to have. Obesity will be prevented by assisting women and men of all ages in maintaining a healthy weight. It is insufficient to concentrate just on women who are about to get pregnant. Regardless, there is strong evidence that maternal obesity promotes additional health issues for both moms and newborns (aside from offspring obesity). As a result, expectant moms should continue to be encouraged and supported in their efforts to maintain a healthy weight. It will be critical to expand this research to look at other factors of mothers and dads during pregnancy and early childhood that may influence children’s weight, as well as to look at offspring when they reach adulthood and are old enough to exhibit early symptoms of heart disease risk.”