Assessment of dietary fish consumption in pregnancy: comparing one-, four- and thirty-six-item questionnaires.

OBJECTIVE: Fish consumption influences a number of health outcomes. Few studies have directly compared dietary assessment methods to determine the best approach to estimating intakes of fish and its component nutrients, including DHA, and toxicants, including methylmercury. Our objective was to compare three methods of assessing fish intake. DESIGN: We assessed 30 d fish intake using three approaches: (i) a single question on total fish consumption; (ii) a brief comprehensive FFQ that included four questions about fish; and (iii) a focused FFQ with thirty-six questions about different finfish and shellfish. SETTING: Obstetrics practices in Boston, MA, USA. SUBJECTS: Fifty-nine pregnant women who consumed ≤2 monthly fish servings. RESULTS: Estimated intakes of fish, DHA and Hg were lowest with the one-question screener and highest with the thirty-six-item fish questionnaire. Estimated intake of DHA with the thirty-six-item questionnaire was 4·4-fold higher (97 v. 22 mg/d), and intake of Hg was 3·8-fold higher (1·6 v. 0·42 µg/d), compared with the one-question screener. Plasma DHA concentration was correlated with fish intake assessed with the one-question screener (Spearman r = 0·27, P = 0·04), but not with the four-item FFQ (r = 0·08, P = 0·54) or the thirty-six-item fish questionnaire (r = 0·01, P = 0·93). In contrast, blood and hair Hg concentrations were similarly correlated with fish and Hg intakes regardless of the assessment method (r = 0·35 to 0·52). CONCLUSIONS: A longer questionnaire provides no advantage over shorter questionnaires in ranking intakes of fish, DHA and Hg compared with biomarkers, but estimates of absolute intakes can vary by as much as fourfold across methods.

A pilot randomized controlled trial to promote healthful fish consumption during pregnancy: the Food for Thought Study.

BACKGROUND: Nutritionists advise pregnant women to eat fish to obtain adequate docosahexaenoic acid (DHA), an essential nutrient important for optimal brain development. However, concern exists that this advice will lead to excess intake of methylmercury, a developmental neurotoxicant. OBJECTIVE: Conduct a pilot intervention to increase consumption of high-DHA, low-mercury fish in pregnancy. METHODS: In April-October 2010 we recruited 61 women in the greater Boston, MA area at 12-22 weeks gestation who consumed <=2 fish servings/month, and obtained outcome data from 55. We randomized participants to 3 arms: Advice to consume low-mercury/high-DHA fish (n=18); Advice + grocery store gift cards (GC) to purchase fish (n=17); or Control messages (n=20). At baseline and 12-week follow-up we estimated intake of fish, DHA and mercury using a 1-month fish intake food frequency questionnaire, and measured plasma DHA and blood and hair total mercury. RESULTS: Baseline characteristics and mean (range) intakes of fish [21 (0-125) g/day] and DHA from fish [91 (0-554) mg/d] were similar in all 3 arms. From baseline to follow-up, intake of fish [Advice: 12 g/day (95% CI: -5, 29), Advice+GC: 22 g/day (5, 39)] and DHA [Advice: 70 mg/d (3, 137), Advice+GC: 161 mg/d (93, 229)] increased in both intervention groups, compared with controls. At follow-up, no control women consumed >= 200mg/d of DHA from fish, compared with 33% in the Advice arm (p=0.005) and 53% in the Advice+GC arm (p=0.0002). We did not detect any differences in mercury intake or in biomarker levels of mercury and DHA between groups. CONCLUSIONS: An educational intervention increased consumption of fish and DHA but not mercury. Future studies are needed to determine intervention effects on pregnancy and childhood health outcomes. TRIAL REGISTRATION: Registered on clinicaltrials.gov as NCT01126762.

A qualitative study of fish consumption during pregnancy.

BACKGROUND: Many pregnant women in the United States do not consume enough docosahexaenoic acid (DHA)--an essential nutrient found in fish. Apparently conflicting findings that fish consumption is beneficial for the developing fetus, yet potentially toxic because of mercury contamination, have created uncertainty about the appropriate fish-consumption advice to provide to pregnant women. OBJECTIVE: Our objective was to determine knowledge, behaviors, and received advice regarding fish consumption among pregnant women who are infrequent consumers of fish. DESIGN: In 2009-2010 we conducted 5 focus groups with 22 pregnant women from the Boston area who ate <2 fish servings/wk. We analyzed transcripts by using immersion-crystallization. RESULTS: Many women knew that fish might contain mercury, a neurotoxin, and had received advice to limit fish intake. Fewer women knew that fish contains DHA or what the function of DHA is. None of the women had received advice to eat fish, and most had not received information about which fish types contain more DHA or less mercury. Because of advice to limit fish intake, as well as a lack of information about which fish types they should be eating, many of the women said that they would rather avoid fish than possibly harm themselves or their infants. The participants thought that a physician's advice to eat fish and a readily available reference regarding which fish are safe to consume during pregnancy would likely have encouraged them to eat more fish. CONCLUSION: Pregnant women might be willing to eat more fish if this were advised by their obstetricians or if they had an accessible reference regarding which types are safe.