The Effect of Omega-3 Docosahexaenoic Acid Supplementation on Gestational Length: Randomized Trial of Supplementation Compared to Nutrition Education for Increasing n-3 Intake from Foods

OBJECTIVE DHA supplementation was compared to nutrition education to increase DHA consumption from fish and DHA fortified foods. DESIGN This two-part intervention included a randomized double-blind placebo controlled DHA supplementation arm and a nutrition education arm designed to increase intake of DHA from dietary sources by 300 mg per day. SETTING Denver Health Hospitals and Clinics, Denver, Colorado, USA. POPULATION 871 pregnant women aged 18-40 were recruited between 16 and 20 weeks of gestation of whom 564 completed the study and complete delivery data was available in 505 women and infants. METHODS Subjects received either 300 or 600 mg DHA or olive oil placebo or nutrition education. MAIN OUTCOME VARIABLE Gestational length. RESULTS Gestational length was significantly increased by 4.0-4.5 days in women supplemented with 600 mg DHA per day or provided with nutrition education. Each 1% increase in RBC DHA at delivery was associated with a 1.6-day increase in gestational length. No significant effects on birth weight, birth length, or head circumference were demonstrated. The rate of early preterm birth (1.7%) in those supplemented with DHA (combined 300 and 600 mg/day) was significantly lower than in controls. CONCLUSION Nutrition education or supplementation with DHA can be effective in increasing gestational length.