The Benefits of DHA During Pregnancy and While Breast-feeding
Docosahexaenoic acid, DHA, is a long chain omega-3 fatty acid that is found throughout the body. It is a major structural fat in the brain and retina of the eye and is a key component of the heart. DHA is always found in breast milk and is considered important for optimal infant brain, eye and nervous system development. DHA has also been shown to support a healthy pregnancy. The last trimester of pregnancy and early years of life are times of rapid and significant brain growth and accumulation of DHA. Visual, neurocognitive, and vascular benefits are evident for infants whose mothers supplemented with DHA during pregnancy and lactation. Experts advise pregnant and lactating women to consume 200 mg DHA/day or more, a level at which health benefits have been demonstrated. However, most women of childbearing age in the U.S. do not consume this amount of DHA.
In supplementation studies, ALA (alpha-linolenic acid) and EPA (eicosapentaenoic acid) — two other omega-3 fatty acids — do not significantly increase DHA levels in maternal blood, umbilical cord blood, or breast milk and as a result, do not provide the benefits associated with DHA. However, supplementation with preformed DHA supports maternal red blood cell (RBC), plasma, cord blood and breast milk DHA levels, and is associated with positive health benefits to the infant and mother. A growing body of research suggests that these health benefits extend well beyond the time of supplementation. Based on this research, in 2010, international authoritative groups such as FAO/WHO (Food and Agriculture Organization of the United Nations; World Health Organization) and AFSSA (French Food Safety Agency) now define DHA as a “conditionally” or “essential fatty acid” with “convincing evidence” of its “critical role in retinal and brain development for 0–24 months of age.”
Below are research highlights from studies examining the role of DHA in development and health during pregnancy and lactation.
The Physiologic Need for DHA
- DHA is the most abundant fatty acid in the brain and retina of the eyes, representing about 97% and 93% of all omega-3 fatty acids in the brain and retina, respectively.
- DHA is critical for healthy vision and mental development in utero and throughout infancy.
- Breast milk is the optimal method for infant feeding. DHA is always present in human breast milk.
- The developing infant receives DHA from their mother via the placenta and in breast milk after birth.
- Expert panels recommend at least a daily intake of 200–300 mg DHA per day during pregnancy and nursing.
- DHA intake during pregnancy is safe. Up to 1 g/day of DHA has been supplemented in research trials.
DHA Intake Influences the DHA Status of Both the Mother and Fetus/Baby
- On average, pregnant and nursing women in North America consume 60–80 mg of DHA a day, only 20–40% of the recommended intake.
- Breast milk DHA levels are dependent on the mother’s diet. Because of a low DHA dietary intake, American women reportedly have lower DHA levels in their breast milk than their international counterparts.
- Maternal DHA supplementation increases the mother’s blood and breast milk DHA levels. This in turn increases the blood DHA levels of both the fetus and breast-fed infant.
DHA Health Benefits to the Child During Pregnancy
Higher maternal red blood cell (RBC), plasma and cord blood DHA are associated with higher scores on measures of neural and visual development in the child.
- Improved visual acuity (clearness of vision) at 4 months of age and problem solving at 9 months of age.
- Significantly higher score for eye and hand coordination at 2.5 years of age (mean score: 114 vs 108).
- Higher cord DHA is associated with longer gestation, better visual acuity and novelty preference on tests of cognition (Fagan Test) at 6 months, and improved mental and psychomotor performance (Bayley Scale) at 11 months.
- School-age children (mean age: 11 years) exposed to high levels of DHA during gestation demonstrate improved function of the visual parvo-cellular pathway, known to mediate visual acuity and color processing.
- Higher maternal plasma DHA is associated with more mature neonatal sleep-state patterning, suggestive of more mature central nervous system development.
- Maternal RBC DHA at delivery is associated with improved scores of attention, indicating some developmental advantages for those infants.
- Maternal DHA intake affects quality of movement at 7 years of age using the Maastricht Motor Test.
DHA Health Benefits to the Child During Lactation
Higher maternal blood, plasma, cord blood and breast milk DHA are associated with higher scores on measures of neural and visual development in the child.
- Infants with higher RBC DHA levels have better visual acuity at 4 months of age.
- Preterm infants fed milk supplemented to 1% DHA (total fatty acids—TFA) demonstrate improved visual acuity at 4 months corrected age over infants receiving standard DHA doses (0.3%TFA). The improvement in acuity was 20/75 compared with 20/60 Snellen equivalents.
- Higher levels of DHA in breast milk are associated with an infant’s ability to easily adjust to changes in surroundings (Brazelton Neonatal Behavioral Assessment scale).
- Higher levels of DHA in breast milk associated with higher scores on a test of cognition (8.4 points higher on Bayley PDI) at 2.5 years of age. Significantly better scores on tests of cognition (the Sustained Attention Subscale of the Leiter International Performance Scale) in 5-year-old schoolchildren are also reported, suggesting long-term benefits of DHA supplementation during lactation.
- Maternal supplementation during pregnancy and lactation improves mental processing at 4 years of age (Mental Processing Composite K-ABC test) and identifies a relationship between IQ at 4 years of age and plasma DHA at 4 weeks of age. DHA may be important for later cognitive function such as sequential processing at age 7.
- A study using a statistical model of risk-benefit analysis, designed by the Harvard Center for Risk Analysis, estimated that increasing maternal DHA intake by 1 g/day increases a child’s IQ by 1.3 points.
DHA Supports Gestation Length
- Supplementation with DHA during pregnancy benefits both mother and baby by extending the length of gestational age. Meta-analyses of studies conducted to date show that maternal DHA supplementation is associated with a length of pregnancy averaging 1.6 to 2.6 days closer to term. One study demonstrated a six-day increase in gestational age.