Maternal weight-status at various time-points may influence child obesity development, however the most critical time-point remains unidentified. We used data from the Healthy Growth Study, a cross-sectional study of 2666 Greek schoolchildren aged 9-13 years, exploring associations between childhood obesity and maternal weight-status at pre-pregnancy, during pregnancy/gestational weight gain, and at the child's pre-adolescence. Logistic regression analyses examined associations between maternal weight-status being "below" or "above" the recommended cut-off points (WHO BMI thresholds or IOM cut-off points), at the three time-points, individually or combined into weight-status trajectory groups to determine the strongest associations with child obesity in pre-adolescence. Adjusted models found significant associations and the highest odds ratios [95% Confidence Intervals] for mothers affected by obesity before pregnancy (4.16 [2.47, 7.02]), those with excessive gestational weight gain during pregnancy (1.50 [1.08, 2.08]), and those affected by obesity at their child's pre-adolescence (3.3 [2.29, 4.87]). When combining these weight-status groups, mothers who were above-above-below (3.24 [1.10, 9.55]), and above-above-above (3.07 [1.95, 4.85]) the healthy weight recommendation-based thresholds in each time-point, had a three-fold higher likelihood of child obesity, compared to the below-below-below trajectory group. Maternal obesity across all examined time-points was significantly associated with childhood obesity. Effective childhood obesity preventive initiatives should commence at pre-conception, targeting maternal weight throughout the life-course and childhood developmental stages.
Keywords: childhood obesity; gestational weight gain; maternal obesity; maternal overweight; perinatal factors; pre-pregnancy.