Possible benefit of the supplementation with omega-3 fatty acids in overweight/obese women during pregnancy


In Western countries up to 30 % of pregnant women are overweight or obese. Overweight/obese women are at higher risk of pregnancy complications, for instance, impaired glucose tolerance and gestational diabetes; furthermore, offspring of mothers with abnormal glucose in the blood during gestation are at greater risk of obesity and diabetes themselves.

One study has assessed the associations of body mass index with fatty acid concentrations among pregnant women; this research showed that as compared with lean women, obese women had lower concentrations of DHA, an omega-3 fatty acid, during pregnancy. Another one has concluded that higher body mass index is associated with higher omega-6 fatty acids concentrations. Moreover, excessive gestational weight gain is associated with higher concentrations of omega-6 fatty acids, but there is no association with omega-3 fatty acids concentrations. That is to say, pregnant women with either obesity or excessive weight gain during pregnancy have an adverse fatty acids profile, characterized by higher concentrations of omega-6 fatty acids and lower concentrations of omega-3 fatty acids. At the same time, higher maternal levels of omega-3 fatty acids have been associated with improved perinatal outcomes and may also influence offspring metabolic health.

Considering that maternal body mass index and fatty acid levels affect inflammatory balance in pregnancy and play a key role in fetal growth and well-being, offspring of overweight/obese women may be need of optimal prenatal nutrition including omega-3 fatty acids. The associations between the maternal omega-6:omega-3 fatty acids ratio and neonatal outcomes according to maternal pre-pregnancy body mass index have been studied: A higher maternal omega-6: omega-3 fatty acids ratio was associated with impaired fetal growth, one day shorter length of gestation, and increased length of neonatal hospital stay in overweight/obese, but not lean, women.

These findings suggest a possible benefit of the supplementation with omega-3 fatty acids in overweight/obese women during pregnancy.



Penfield-Cyr A, Monthe-Dreze C, Smid MC, Sen S. Maternal BMI, mid-pregnancy fatty acid concentrations, and perinatal outcomes. Clin Ther. 2018 Sep 18. doi: 10.1016/j.clinthera.2018.08.011. [Epub ahead of print]

Vidakovic AJ, Jaddoe VW, Gishti O, Felix JF, Williams MA, Hofman A, et al. Body mass index, gestational weight gain and fatty acid concentrations during pregnancy: the Generation R Study. Eur J Epidemiol. 2015;30(11):1175-85.

Maslova E, Rifas-Shiman SL, Olsen SF, Gillman MW, Oken E. Prenatal omega-3 long-chain fatty acid status and offspring metabolic health in early and mid-childhood: results from Project Viva. Nutrition & Diabetes. 2018;8, Article number: 29.