Band 35, Heft s1

Considerable evidence exists for marked beneficial effects of omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) during pregnancy. The omega-3 LC-PUFA docosahexaenoic acid (DHA) is incorporated in large amounts in fetal brain and other tissues during the second half of pregnancy, and several studies have provided evidence for a link between early DHA status of the mother and visual and cognitive development of her child after birth. Moreover, the supplementation of omega-3 LC-PUFA during pregnancy increases slightly infant size at birth, and significantly reduces early preterm birth before 34 weeks of gestation by 31%. In our studies using stable isotope methodology in vivo , we demonstrated active and preferential materno-fetal transfer of DHA across the human placenta and found the expression of human placental fatty acid binding and transport proteins. From the correlation of DHA values with placental fatty acid transport protein 4 (FATP 4), we conclude that this protein is of key importance in mediating DHA transport across the human placenta. Given the great importance of placental DHA transport for infant outcome, further studies are needed to fully appreciate the effects and optimal strategies of omega-3 fatty acid interventions in pregnancy, dose response relationships, and the potential differences between subgroups of subjects such as women with gestational diabetes or other gestational pathology. Such studies should contribute to optimize substrate intake during pregnancy and lactation that may improve pregnancy outcome as well as fetal growth and development.

Epidemiological data suggest that dietary factors may have a role in recent increases of the prevalence of allergic diseases. One food-related component might be the reduced consumption of ω3-polyunsaturated fatty acids observed especially in the Western societies; yet, clinical trials supplementing ω3-fatty acids to adults with established allergies and bronchial asthma have generally been disappointing. However, it is known that the immature immune system is highly susceptible to immuno-modulatory environmental conditions particularly in the pre- and postnatal period. This review discusses the immuno-modulatory effects of ω3-fatty acids supplementation in the perinatal life phase on the immune system of the child. Evidence exists that perinatal ω3-fatty acid exposure affects T-cells and antigen presenting cells of the neonates likely due to altered eicosanoid metabolism. Although animal experiments strongly suggest a role of maternal ω3-fatty acid intake on allergic immune responses in the offspring, the beneficial effect of ω3-fatty acid supplementation has been studied in a small number of clinical trials. In these studies perinatal supplementation had some positive effects on distinct clinical phenotypes of the atopic syndrome. However, more studies are needed to fully explore the opportunity of perinatal immuno-modulation.

There is a rising interest in a balanced and varied women's diet not only preconceptionally but also during pregnancy and in the breastfeeding period in order to reduce fetal, neonatal, and maternal risks. A decreased intake of omega 3-fatty acids (FA) or deficiencies of micronutrients are a global health problem, not only in developing countries, where micronutrient-rich food and fortified aliments are often not available, and also in the industrialized world. In contrast to data about the daily periconceptionally intake of folate acid that has been shown to reduce substantially the occurrence and recurrence of neural tube defects (NTD), the benefit of other micronutrients is less determinant. Deficiencies of omega 3-FA may be a contributing factor for severe complications in pregnancy and postpartum. A meta-analysis for the role of omega 3-FA in preeclampsia and maternal postpartum depression is less consistent, some meta-view's results differ substantially or are even contradictory to large observational studies. Further well-designed studies are warranted. A personal interview and counseling concerning the daily diet should be integrated in the preconceptional and in the antenatal care and an individual supplementation should be offered, if indicated.

A literature review was performed on the effect of fish oil on preterm birth in observational and randomized studies. The only weak effect on preterm birth found in meta-analyses could be caused by the low compliance, and the fact that many women stop supplementation before term together with a fast acting effect on fish oil.

The present review addresses the effect of pre- and postnatal supplementation of nutrition with long-chain polyunsaturated fatty acids (LCPUFA) on neurodevelopmental outcome. The few studies which addressed the effect of prenatal LCPUFA status or prenatal LCPUFA supplementation suggest that a better prenatal arachidonic acid (AA) and doxosahexaenoic acid (DHA) status might be related to a better neurodevelopmental outcome until at least 18 months of age. A review of the few randomized controlled trials on formula supplementation with LCPUFA in preterm infants did not provide evidence for a significant beneficial effect of LCPUFA on developmental outcome. A review of the trials on formula supplementation with LCPUFA in term infants revealed that supplementation with LCPUFA, in particularly supplementation with ≥0.30% DHA, has a beneficial effect on neurodevelopmental outcome until 4 months. The studies could not demonstrate a consistent positive effect beyond that age. It was concluded that the relatively subtle effects of LCPUFA supplementation on neurodevelopmental outcome do not only depend on dosage but also on the gestational period during which the nutritional components are supplied: supplementation prior to term seems to have more effect than that after term.