The Association Between Maternal Prenatal Fish Intake and Child Autism-Related Traits in the EARLI and HOME Studies

Abstract

We examined the association between prenatal fish intake and child autism-related traits according to Social Responsiveness Scale (SRS) and cognitive development scores in two US prospective pregnancy cohorts. In adjusted linear regression analyses, higher maternal fish intake in the second half of pregnancy was associated with increased child autism traits (higher raw SRS scores; ß = 5.60, 95%CI 1.76, 12.97). Differences by fish type were suggested; shellfish and large fish species were associated with increases, and salmon with decreases, in child SRS scores. Clear patterns with cognitive scores in the two cohorts were not observed. Future work should further evaluate potential critical windows of prenatal fish intake, and the role of different fish types in association with child autism-related outcomes.

Appendix

EARLI and HOME fish questions and harmonization process.

	EARLI		HOME
	Question	Response values	Question	Response values
Overall fish intake	During the first 20 weeks of your current pregnancy, how many servings of seafood, including fish and shellfish (including canned tuna or tuna in foil pouches) did you eat per week or per day?	< 1 times per week 1–2 times per week 3–4 times per week 5–6 times per week 1 per day 2 or more per day	From {conception} until today how often did you eat fish or shellfish, on average?	Not at all  < 1 times per month 1–3 times per month 1–3 times per week 4–6 times per week Almost every day
Intake of fish types	How often did you eat shellfish such as shrimp oysters, clams, crab, crayfish, or lobsters?a How often did you eat fish sticks or fried fish? (NOT including shrimp or other shellfish) How often did you eat fish that was NOT FRIED? (not including shrimp or other shellfish and not including canned tuna or tuna in foil pouches)	< 1 times per week 1–2 times per week 3–4 times per week 5–6 times per week 1 per day 2 or more per day	Participants were asked to report intake of the following fish: Carp Bass Catfish Drumfish Bullhead Swordfish Shark Tuna of any type Mackerel Tilefish Shellfish, such as lobster, crab, shrimp, clams, or oysters Salmon Lake trout	Responses were provided as number of times participant ate that type of fish during the time period
	When you ate fish that was NOT fried, how often was that fish salmon? When you ate fish that was NOT fried, how often was that fish tuna steaks or other fresh tuna? When you ate fish that was NOT fried, how often was the fish swordfish, shark, tilefish, or king mackerel?	Almost never or never About ¼ of the time About ½ of the time About ¾ of the time Almost always or always Don’t Know

1. *Questions shown for first half of pregnancy FFQ; questions for second half of pregnancy asked about intake since the first questionnaire rather than since conception
2. ^aSupplemental questions asked about serving size (for all fish types), whether the shellfish was fried, and what proportion of the time the intake was shrimp

Harmonization scheme for overall frequency of fish intake for early and late pregnancy.

Combined Definition	EARLI value	HOME value
0 = None	None, Don’t Know, Missing	Not at all, Missing
1 = Very Low	< 1 per week	1–3/month, < 1/month
2 = Medium	1–2, 3–4, 5–6/week	1–3, 4–6/week
3 = High	1/day and 2 + /day	Almost every day