Eating fish in pregnancy? Less risk of premature birth

Consuming fish rich in omega three, at least once a week, during gestation would reduce the risk of preterm birth. Intake of 3 servings per week would also promote higher birth weight of the baby. A diet that includes the right amount of seafood is therefore advisable during pregnancy.

This is the finding of a study conducted by researchers at the University of Crete and published in the American Journal of Nutrition.

Fish in pregnancy yes or no? 

Consumption of fish containing the Omega-3 EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) is associated with a reduced risk of defects in neurodevelopment and visual apparatus in the fetus. However, the presence of health-damaging contaminants, such as methylmercury, polychlorinated biphenyls (PCBs) and dioxin, has prompted many people in recent years to exclude fish from their diets or to take purified fish oil supplements. Methylmercury is a toxic molecule easily absorbed by tissues and harmful to the heart and nervous system. PCBs are carcinogenic compounds used in industrial and commercial processes until 1977. 

They are now banned but may still be present in some foods. Dioxins are a group of toxic components that affect the endocrine and immune system. In any case, as specified by the official guidelines of the U.S. Department of Agriculture (USDA), for proper nutrition the consumption of different varieties of fish and seafood is still advisable. For women who are pregnant, lactating or planning to become pregnant, and for children under the age of 12, the USDA recommends consuming fish in safe doses, i.e., about 340 grams per week, including 170 grams of canned albacore tuna, avoiding species high in mercury, such as swordfish, shark or mackerel.

Positative on the health of the child

The research looked at 19 European studies with a total of 151,880 mother-child pairs. Analysis of the data collected showed that women who had consumed fish more than once a week during gestation had an 11-13% lower risk of preterm delivery, compared with those who ate it less frequently. 

Mothers who had consumed it at least 1 or 2 times a week had given birth to babies weighing 8.9 grams more than those who had not consumed any. The babies' weight was 15.2 grams higher if the mothers had consumed at least 3 servings of fish per week.

Positive effects of Omega-3 rich fish

The results suggest the positive effect of fish on infant birth weight and full gestation. According to the researchers, these effects would be due to the action of EPA and DHA . A 'hypothesis confirmed by the fact that the most pronounced results on infant weight were observed in women who had consumed fatty fish, that is, containing higher amounts of Omega-3. 

During pregnancy, maternal serum loses high concentrations of DHA, and synthesis of polyunsaturated fatty acids in the placenta and fetus is very low. Maternal Omega-3 levels and placental function are essential for adequate supply to the fetus. This study could end the debate about fish consumption during gestation by suggesting that women consume fish in the right amounts.

 Source: Vasiliki Leventakou et al. "Fish intake during pregnancy, fetal growth, and gestational length in 19 European birth cohort studies" Am J Clin Nutr 2014 99: 3 506-516; First published online December 11, 2013.