Being obese before conception triples odds of obese or overweight offspring, review findsBMJ 2019; 365 doi: https://doi.org/10.1136/bmj.l4187 (Published 12 June 2019) Cite this as: BMJ 2019;365:l4187
Women who are obese before becoming pregnant have more than three times the odds of having obese or overweight offspring when compared with women of a healthy weight, a systematic review and meta-analysis has found.1
“This research has identified the need for early intervention in the prevention of childhood obesity, starting before conception,” said the study authors, led by Nicola Heslehurst of Newcastle University, UK. “For many years, prevention interventions have targeted environmental settings, such as schools. However, increasing obesity prevalence in preschool age children highlights the importance of earlier prevention.”
The study analysed data from 79 studies looking at the association between maternal pre-pregnancy body mass index (BMI) and childhood weight status. These included 20 studies of child obesity (n=88 872), 22 studies of child overweight/obesity (n=181 800) and 10 studies of child overweight (n=53 238).
Reported in PLOS Medicine,1 the results showed that maternal obesity before pregnancy was significantly more associated with child obesity (odds ratio 3.64 (95% confidence interval 2.68 to 4.95)) than the recommended maternal BMI of 18.5 to 24.9. It was also associated with child overweight/obesity combined (odds ratio 2.69 (2.10 to 3.46)) and child overweight (1.80 (1.25 to 2.59)).
“Little attention has been given to the preconception period among obesity prevention interventions to date,” the study authors wrote. “Attention to this period may help to address the complex early-life inequalities associated with obesity development.”
The researchers acknowledged some limitations of their review, which was supported by funding from the Medical Research Council, the Economic and Social Research Council, and Newcastle University Research Excellence. These included significant study heterogeneity, some of the original studies not reporting data in a format that could be included in the meta-analysis, and the failure of some studies to account for factors such as gestational weight gain and diabetes.
But they considered that they had used a rigorous search strategy and measures to minimise human error and subjectivity, as well as contacting study authors for additional information.