Nutrition - DHA and pregnancy - DHA for mother

Mar 2014   DHA for mother and pregnancy
Research studies have established that adequate dietary docosahexaenoic acid (DHA) intake by mother during pregnancy is vital for the proper development of the brain, nervous system and retina of the fetus.
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DHA for mother

Docosahexaenoic acid is the major structural fat constituent of the brain and retina. With the evolutionary progress towards higher intelligence, human brain size has also increased. Compared to the brain size of other mammals, human brain size, is quite large. To cope up with the docosahexaenoic acid demand of the fetus, there is selective DHA transfer from the mother to the fetus. Even after the birth, the newborn is provided with docosahexaenoic acid in breast milk. Compared to dairy milk, breast milk contains significant amounts this omega-3 fat.

Docosahexaenoic acid concentrations in breast milk range between 0.07% to to 1.0% of the total fatty acids, when the mother is taking normal diet. With the increased addition of fish or docosahexaenoic acid supplements in the diet, the DHA levels in the breast milk can increase drastically.

Considering the importance of docosahexaenoic acid, FDA had released an advisory to women planning a pregnancy, pregnant women and also breastfeeding women to eat up to 12 ounces of canned light tuna, catfish, pollock, salmon and shrimp in a week. Because of the possibility of toxins and mercury contamination, they are advised against eating shark, swordfish, king mackerel, or tilefish.

However majority of the pregnant women in United States fail to include the recommended amount of DHA in their diet. The fast food era has changed the food habits and there is a steep decrease in the consumption of preformed DHA resulting in low stores of docosahexaenoic acid in young women and would-be mothers.

DHA and pregnancy

Inadequate intake of docosahexaenoic acid during pregnancy may cause low plasma and erythrocyte DHA levels leading to reduced cognitive development, retinal development, eye-hand coordination and visual acuity in the infant. International Society for the Study of Fatty Acids and Lipids (ISSFAL) participated in the PERILIP consensus process and recommended an average dietary intake of at least 200 mg DHA/day for pregnant and lactating women.

There is threefold increase in the size of the fetal brain during the final trimester of pregnancy. The placenta selectively extracts DHA from the mother's blood and concentrates them in the fetal blood. During this preferential DHA transfer, substantial amounts of docosahexaenoic acid is transferred from the mother causing decline and depletion of this omega-3 fat in her blood.

By the end of last trimester the blood concentration of docosahexaenoic acid in the fetus may be twice that of mother. Nursing the newborn further depletes the mother. If the mother's diet is poor in this omega-3 fat during pregnancy, the supply to the fetus may become insufficient and affect the neurological and early visual development of the baby. The depletion of mother's DHA can cause Postpartum depression or postnatal depression. If not properly topped up with lost omega-3 fat in the mother, future pregnancy may result in infant with all the symptoms of docosahexaenoic acid depletion.

Susan E Carlson et all in their double-blind, randomized controlled trial conducted between January 2006 and October 2011 concluded that "A supplement of 600 mg DHA/d in the last half of gestation resulted in overall greater gestation duration and infant size". The reduction in preterm births and increase birth-weight will have a great positive impact on clinical mother and child care and public health.

An infant born at the end of full-term pregnancy will have greater brain growth when compared to a preterm child. Infants born preterm are at the risk of incomplete docosahexaenoic acid accumulation from the mother as they are denied the full gestation period to accumulate DHA.

Children whose mothers had higher blood levels of docosahexaenoic acid during pregnancy, were found to have advanced levels of attention span, intelligence and visual acuity. Infants whose mothers included omega-3 supplements in their diets during pregnancy had fewer cold episodes and cold related symptoms. In a research study it was found that women with preeclampsia (hypertension during pregnancy) had lower levels of docosahexaenoic acid. It suggests that DHA suppplementation may protect against preeclampsia in mothers to-be.

References:
1.Susan E Carlson, John Colombo, Byron J Gajewski, Kathleen M Gustafson, David Mundy, John Yeast, Michael K Georgieff, Lisa A Markley, Elizabeth H Kerling, and D Jill Shaddy. DHA supplementation and pregnancy outcomes. Am J Clin Nutr April 2013 ajcn.050021.

Current topic on nutritional deficiency diseases:
DHA - pregnancy - mother

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