Maternal plasma polyunsaturated fatty acid status in late pregnancy is associated with offspring body composition in childhood.

CONTEXT: Maternal diet during pregnancy has been linked to offspring adiposity, but it is unclear whether maternal polyunsaturated fatty acid (PUFA) status during pregnancy affects offspring body composition. OBJECTIVE: We investigated the associations between maternal plasma n-3 and n-6 PUFA status at 34 wk gestation and offspring body composition. DESIGN AND SETTING: A prospective United Kingdom population-based mother-offspring cohort, the Southampton Women's Survey (SWS), was studied. PARTICIPANTS: A total of 12,583 nonpregnant women were recruited into the SWS, among whom 1987 delivered a baby before December 31, 2003; 293 mother-child pairs had complete measurements of maternal plasma PUFA concentrations in late pregnancy and offspring body composition at both ages 4 and 6 yr. MAIN OUTCOMES MEASURED: We measured offspring body composition by dual-energy x-ray absorptiometry, yielding fat mass, lean mass, percentage fat mass, and percentage lean mass. Results are presented as β-coefficients for standardized variables, therefore reflecting the sd change of the outcome for every 1 sd of the predictor. RESULTS: After adjustment for maternal factors and child factors including height and duration of breast-feeding, maternal plasma n-6 PUFA concentration positively predicted offspring fat mass at 4 yr (β = 0.14 SD/SD; P = 0.01) and 6 yr (β = 0.11 SD/SD; P = 0.04), but there was no association with offspring lean mass at either age (β = 0.005 SD/SD, P = 0.89; and β = 0.008 SD/SD, P = 0.81, respectively). Maternal plasma n-3 PUFA concentration was not associated with offspring fat mass at 4 yr (β = 0.057 SD/SD; P = 0.34) or 6 yr (β = 0.069 SD/SD; P = 0.21). Maternal plasma n-3 PUFA status was positively associated with offspring lean mass on univariate analysis (4 yr, β = 0.11, P = 0.06; 6 yr, β = 0.14; P = 0.02); however, this was confounded by a positive association with offspring height. CONCLUSIONS: This observational study suggests that maternal n-6 PUFA status during pregnancy might influence offspring adiposity in childhood.