Plasma Levels of n-6 PUFAs in Pregnancy Associated with Greater Fat in Offspring

PUFA4.13_Callout11The effects of maternal diet and nutrition during pregnancy may reach into adulthood in the offspring. For example, maternal under- or over-nutrition and diabetes have been associated with greater adiposity in the child. Catchup growth after intrauterine growth restriction has been associated with alterations in the expression of insulin-signaling proteins, which may foreshadow insulin resistance. Western-style diets high in linoleic acid have been associated with greater fat mass in successive generations of experimental animals and may be implicated in human obesity. The effects on body composition of maternal and infant consumption of long-chain omega-3 PUFAs (n-3 LC-PUFAs) are inconsistent. Supplementation of pregnant women with n-3 LC-PUFAs during pregnancy and lactation has generally shown no association with body mass index or skinfold thickness in the offspring through 19 years of age. Investigators at the University of Southampton, U.K., conducted a study of healthy nonpregnant women aged 20 to 34 years to characterize preconceptual maternal factors with the potential to affect fetal growth and development and monitored the development of the offspring of all pregnancies. This report focused on the relationship between maternal PUFAs in late pregnancy and the body composition of the children. From a total of 1,987 singleton live births, 293 mother-child pairs completed the assessment of maternal plasma phosphatidylcholine (PC) fatty acids at 34 weeks’ gestation and anthropometric measurements in the children at ages 4 and 6. The researchers measured the children’s body composition using dual-energy x-ray absorptiometry from which lean and fat mass were calculated. Boys and girls were similar in height and weight at 4 and 6 years of age, but girls had significantly greater fat mass and less lean mass than boys at both ages. Some maternal PUFAs were significantly related to the children’s height and weight at 4 and 6 years of age, but these associations were not statistically significant when the analysis was adjusted for maternal age, parity, social class and 8 other variables. Maternal total and individual n-3 PUFAs were not associated with the children’s height, weight, fat or lean mass at either age in multivariate analysis. The investigators observed a trend toward a positive association between maternal n-3 PUFAs and EPA and the child’s height at age 4, but these associations were not observed in multivariate analysis. The observation with total n-3 PUFAs and height was significant at age 6, however (Table).PUFA4.13_Callout12 In contrast, maternal plasma PC total n-6 PUFAs and linoleic acid were significantly associated with greater fat mass and percent fat mass in the multivariate analysis of children at both 4 and 6 years of age (Table). Only total n-6 PUFAs did not reach statistical significance in the adjusted analysis of the percent fat mass in 6-year-old children. Arachidonic acid was not associated with any body composition measurement in the adjusted analysis of children at both ages. Lean body mass was not associated with any maternal PUFA in multivariate analysis, but percent lean mass was significantly lower with higher maternal linoleic acid in the adjusted analysis at both ages. The obserPUFA-4.13-Table2vation that maternal plasma PC n-6 PUFAs and linoleic acid were associated with greater adiposity in the offspring at age 4, which persisted to age 6, suggests that prenatal exposure to n-6 PUFAs in the presence of low concentrations of n-3 LC-PUFAs might increase the risk of childhood obesity. Such a relationship has been demonstrated in animals, but was not observed in a U.S. pregnancy cohort. However, high intakes of linoleic acid have been postulated as an early determinant of childhood obesity. It will be worth watching to see whether the risk of obesity is greater in the offspring of mothers with higher concentrations of n-6 PUFAs when they are older. It would be noteworthy, too, if these observations were confirmed in other studies, especially those using dual x-ray absorptiometry to assess body fat. Whether these associations would be observed in the presence of higher maternal concentrations of n-3 LC-PUFAs is also unknown. Moon RJ, Harvey NC, Robinson SM, Ntani G, Davies JH, Inskip HM, Godfrey KM, Dennison EM, Calder PC, Cooper C; the SWS Study Group. Maternal plasma polyunsaturated fatty acid status in late pregnancy is associated with offspring body composition in childhood. J Clin Endocrinol Metab 2013;98:299-307. [PubMed]