Maternal overweight/obesity has been associated with an increased risk of obesity in childhood. We investigated the effect of maternal overweight/obesity during pre-pregnancy and whether it is a stronger predictor of child obesity, compared to maternal overweight/obesity during childhood. Prospective or retrospective cohort studies published in English, reporting on obese children and adolescents (2-18 years), with overweight/obese mothers in either pre-pregnancy or during childhood were included. A search was conducted from 2012 to April 2022 in MEDLINE, Web of Science, CINAHL, and EMBASE, followed by screening, data extraction, quality assessment and narrative synthesis. Eleven eligible studies (9 prospective and 2 retrospective cohort studies; total sample, n = 27,505) were identified. Eight studies examined maternal overweight/obesity in pre-conception, presenting consistent positive associations with childhood obesity, three reported positive associations between childhood obesity and maternal overweight/obesity during childhood, and one presented positive associations between both maternal exposures. The narrative synthesis failed to identify which maternal exposure is the strongest predictor of childhood obesity, with studies reporting significant associations between maternal overweight/obesity and child obesity in both time points. Intervention programs aiming to reduce childhood obesity should focus on supporting women of childbearing age with weight management from preconception and throughout their life-course.
Keywords: maternal obesity; obesogenic environment; pediatric obesity; pre-pregnancy BMI.