It is known that the high maternal BMI before or during pregnancy is associated with higher BMI in infants, however, to what extent does mother’s weight cause childhood obesity, or is it caused by environmental and lifestyle factors after conception and birth? It is uncertain.
The University of Bristol research team used a method known as Mendelian randomization, which measures genetic variation to determine the effect of an exposure on an outcome.
They studied and noted the birthweight and BMI in both Children of the 90s and Born in Bradford participants at ages 1 and 4 years, and then also BMI at age 10 and 15 years in Children of the 90s participants alone.
They found that there was a moderate causal effect between maternal BMI and child birth weight, although they did not detect a strong causal effect in most adults.
Lead author Dr. Tom Bond, senior research associate at the University of Bristol explained, “We found that if women are heavier at the start of pregnancy this isn’t a strong cause of their children being heavier as teenagers. This is important to know. Supporting women and men at all ages to keep a healthy weight will be needed to prevent obesity. It isn’t enough to just focus on women entering pregnancy. Despite this, there is good evidence that maternal obesity causes other health problems for mothers and babies (aside from offspring obesity). So prospective mothers should still be encouraged and supported to maintain a healthy weight. It will be important to broaden this work to investigate other characteristics of mothers and fathers during pregnancy and a child’s early life that might affect children’s weight, and also to look at the offspring when they are in adulthood and are old enough to begin showing early signs of heart disease risk.”
About Children of the 90s
Children of the 90s, also known as the Avon Longitudinal Study of Parents and Children (ALSPAC), is a long-term health and research project, based at the University of Bristol that had enrolled more than 14,000 pregnant women in 1991 and 1992.
It has been extensively following the health and development of parents and their children ever since, and is currently incorporating original children and siblings into the study. It receives core funding from the Medical Research Council, the Wellcome Trust, and the University of Bristol.
Born in Bradford
Born in Bradford is a research programme that is recognized internationally, which aims to find out what keeps families healthy and happy. This information can be used to develop, implement, and evaluate ambitious plans to improve public health in collaboration with local authorities, health, education, and volunteer sector providers across the Bradford district.
We have a vast ‘city of research’ infrastructure, which includes detailed health and wellbeing information on Bradfordians enrolled in our three birth cohort studies and a connected routine dataset of health, social care, and education data for over 700,000 citizens living in Bradford and Airedale. We host a range of initiatives to improve health working with the local authority, health, education, cultural, and voluntary sector providers.