It is vitally important for an expectant mother to consider carefully what she eats, to ensure a safe and healthy pregnancy and provide the best chance of healthy growth for her baby.
In the last three months of pregnancy, the need for essential omega 3 fatty acids is increased significantly, as this is the stage for brain development in the baby and DHA fatty acids are required. DHA is preferentially transferred from the mother’s placenta to the foetus and thus she must have sufficient stores, or dietary intake, to do this.
In areas / countries where pregnant women consume large amounts of fish (and presumably high intakes of long-chain omega 3 fatty acids, EPA and DHA) there seems to be beneficial effects for the mother: a slightly longer pregnancy (by 1-3 days), slightly larger birth weight and also a possible decrease in pre-eclampsia incidence*,**, as well as a reduction in the risk of pre-maturity.
Emerging research suggests that there may be a role for supplementation of long-chain omega 3 fatty acids in women who develop gestational diabetes during pregnancy, as their fatty acid profile may be changed due to their condition***. It is important that women who have gestational diabetes have their health, including their fatty acid profile, monitored carefully for the duration of their pregnancy.
The developing foetus requires omega 3 fatty acids for cell membranes and physiological functions, as well as for the brain and retina. The foetus requires a constant supply of this from the mother and is therefore dependent on the maternal supply.
Once the baby is born, the mother needs a good supply of essential omega 3 fatty acids, not only to replenish her own body stores, but also to maintain the supply to her baby if she chooses to breast-feed her child. At this early stage in life, development in the brain, the eyes and the nervous system are still continuing.
Also at this point of critical development, it is vital that the baby is receiving adequate amounts of good nutrition and breast milk is a source of the long-chain omega 3 fatty acids (DHA) for the infant. Women who eat more oil-rich fish can increase the amount of DHA in the breast milk, thus improving the amount available to the baby. The best way to increase the infant DHA supply is to simply provide more to the lactating mother.
If a woman chooses to use formula milk, essential omega 3 fatty acids are still available to the child. Although formulas are trying to mimic the composition of breast milk as closely as possible, there are still some differences. For example, some do not provide DHA directly. Breast-fed babies tend to have more mature sight skills and higher IQ than bottle-fed babies and this could be a result of the difference in essential omega 3 fatty acid composition (however, these studies were done prior to the availability of formula with added long-chain polyunsaturates).
Babies that are born pre-maturely and miss out on the umbilical DHA supply during the last stage of development, are born with low stores of DHA in the brain and liver. This can lead to visual impairment and abnormal retina function. Thus, pre-mature babies are given extra fatty acids in their feeds to make up for this. As these fatty acids are needed for eyesight and brain function, there is some evidence which shows that a lack of DHA in the pre-term infant can lead to neurological deficits, such as learning disabilities, social / behavioural problems and perhaps lower scores on IQ tests. Growth of the newborn is also affected by this deficiency, and babies that have been supplemented with DHA and AA have had improved growth compared to those that did not****.
ther tests that could be indicative of developmental problems include testing the visual acuity of the baby. Some studies have shown that two-to-four month old breast-fed infants have better visual acuity than those that were bottle-fed*****.
References
* Olsen SF Consumption of marine n-3 fatty acids during pregnancy as a possible determinant of birth weight. A review of current epidemiological evidence. 1993 Epidemiologic Reviews 15; 399-413
** Hornstra G. Essential Fatty acids in mothers and their neonates. American Journal of Clinical Nutrition. 2000 71(s) 1262-1269
*** Wijendran V, Bendel RB, Couch SC, Philipson EH, Cheruku S, Lammi-Keefe CJ. Fetal Erythrocyte phospholipid polyunsaturated fatty acids are altered in pregnancy complicated with gestational diabetes mellitus. Lipids 2000;35(8): 927-931
**** Innis Sm Adamkin DH, Hall RT et al. Docosahexanoeic acid and arachidonic acid enhance growth with no adverse effects in preterm infants fed formula. Journal of Pediatrics 2002 10; 547-554
***** Birch EE, Garfield S, Hoffman DR, Uauy R. Dietary essential fatty acid supply and visual acuity development. Investigative Ophthalmology and Visual Science. 1992 33 3242-3253