The effect of prenatal docosahexaenoic acid supplementation on infant outcomes in African American women living in low-income environments: A randomized, controlled trial

Abstract

Importance: African American women living in urban, low-income environments are at high risk for poor nutrition during pregnancy and birth complications.

Objective: To test the effectiveness of prenatal docosahexaenoic acid (DHA) supplementation on birth outcomes and infant development in a sample of African American women with Medicaid insurance and living in the city of Pittsburgh.

Design: The Nutrition and Pregnancy Study (NAPS) is a double-blind, randomized controlled trial of prenatal DHA supplementation conducted between 2012 and 2014.

Setting: Participants were recruited from obstetric clinics at the University of Pittsburgh Medical Center.

Participants: Sixty-four pregnant, African American women were enrolled at 16-21 weeks of gestation and randomized to either 450mg/day of DHA (22:6n-3)(n=43) or a soybean placebo (n=21). Four women (6.3%) withdrew from the study: two participants from each study arm; complete data were obtained for 49 infants (76.5%) at the 3-month assessment.

Interventions: Supplementation with DHA or placebo continued from the beginning of enrollment through delivery.

Main outcome and measures: Data on birth outcomes were collected from medical records. At approximately 3 months post-partum, mothers brought their infants to the laboratory where the Bayley Scales of Infant Development (BSID-III) were administered and cortisol response to the Face-to-Face Still-Face (FFSF) paradigm was assessed.

Results: Infants of mothers who received DHA supplementation had higher birth weight (3.174g versus 2.890g) than infants of mothers receiving placebo (F [2.40]=6.09, p=0.018, eta=0.36), and were more likely to have a 1-min Apgar score greater than 8 (OR=5.99 [95% CI=1.25-28.75], p=0.025). Infants of mothers who received DHA compared with infants of mothers receiving placebo had lower levels of cortisol in response to the FFSF paradigm (F [1.32]=5.36, p=0.018, eta=0.36). None of the scores on the BSID-III differed as a function of active supplement versus placebo.

Conclusions: Infants of women living in urban, low-income environments who received DHA supplementation had more optimal birth outcomes and more modulated cortisol response to a stressor. DHA supplementation may be effective in attenuating the negative effects of prenatal stress on offspring development.

Keywords: Birth outcomes; Cortisol; Docosahexaenoic acid; Infant; Prenatal stress; Supplementation.

Figure 1

Nutrition and pregnancy study participation rates

Figure 2

Effect of supplementation on birth weight controlling for gestational age at birth F (1,40) = 6.09, p = .018, cohen’s d = .77, controlling for gestational age; n for placebo = 13; n for active = 30; error bars represent standard error for the mean within each group

Figure 3

Effect of supplementation on one minute Apgar controlling for gestational age and birth weight Odds ratio = 5.99 (95% CI = 1.25–28.75), p = .025, controlling for birth weight and gestational age; n for placebo = 13; n for active = 30

Figure 4

Effect of supplementation of infant cortisol response to the Still-Face Paradigm F (1, 32) = 5.36, p = .027, cohen’s d = .82, Controlling for time of collection and pre-stressor cortisol levels; error bars represent standard error for the mean within each group at each time point