A clinical trial in Australian perinatal centers was conducted to assess the efficacy and safety of DHA (docosahexaenoic acid) supplementation on the risk-reduction of postpartum maternal depression and improvement of early cognitive development in the offspring. Pregnant women were given capsules containing fish oil rich in DHA from early pregnancy until after childbirth. According to the results, there was neither a reduction in postpartum depression, nor an improvement in the cognitive development of offspring with intake of DHA. However, no major safety concern was identified for either the mother or the infant with DHA supplementation.
Epidemiological studies have demonstrated that fish and seafood containing “n-3 long-chain polyunsaturated fatty acids” are good for reducing the effects of postpartum depression in mothers and for enhancing brain development in the babies. However, previous trials have shown mixed effects, mainly due to methodological limitations. Despite the dearth of data, recommendations suggest an increase in dietary DHA during pregnancy; thereby DHA supplements continue to flourish in the pregnancy supplement market. The investigative team was hoping to find out whether “whether increasing DHA during the last half of pregnancy will result in fewer women with high levels of depressive symptoms and enhance the neurodevelopmental outcome of their children.”
- Pregnant women (with or without diagnosis of depression) within 21 weeks of gestation were enrolled and randomly assigned either to the DHA group (receiving three DHA capsules a day) or a control group (receiving three vegetable oil capsules a day). They continued the treatment until the time of delivery.
- At six weeks postpartum and again at six months postpartum, the mothers assessed themselves for depressive symptoms, using a standard scale.
- Cognitive development of infants at 18 months was studied by a psychologist, using Bayley Scales.
- There was no statistically significant difference in the number of new depressive symptoms in women being treated with or without DHA supplementation. Neither was any reduction in depression scores observed in the women who were diagnosed as depressed at the beginning of the study, among both groups.
- There was also no significant change in mean cognitive scores in infants of women from the DHA group, as compared to control group. However, girls showed delayed development in certain areas of cognition (language and behavior adaption) as compared to boys.
- There were no death cases reported during pregnancy and the frequency of distribution of serious adverse events was similar in infants among both groups.
One limitation of the study could be that women with high scores of depression were not verified with clinical diagnosis of depression. Moreover, there was an imbalance among girls in DHA group, with respect to delayed language development, which needs to be confirmed by looking at the residual effect of DHA on cognitive outcomes at later ages.
DHA supplementation has been widely used during pregnancy to optimize brain function of mother and infant, without any confirmatory clinical trails. However, the authors of this study state that their results “do not support routine DHA supplementation for pregnant women to reduce depressive symptoms or to improve cognitive or language outcomes in early childhood”. It would be interesting to know whether nutrients other than DHA contribute to the overall effect claimed by earlier studies that support DHA supplementation during pregnancy. “Further studies are required to determine whether there are specific benefits of DHA supplementations for women with a previous history of depression and for women at risk of pre-term birth.”
For More Information:
Publication Journal: Journal of American Medical Association, October 2010
By Maria Makrides, PhD; Robert A. Gibson, PhD; Women’s and Children’s Hospital, North Adelaide, Australia; the School of Pediatrics and Reproductive Health and the School of Agriculture, Food and Wine, University of Adelaide, Australia