A new international study reports that a moderate fish intake during pregnancy seems to be associated with a lower risk of preterm birth and a small increase in birth weight.
The study analyzed data from 19 European cohort studies on the frequency of total fish, fatty fish, lean fish, and seafood intake (based on questionnaires) during the pregnancy of 151,880 mothers, the birth weight of their children and documented cases of preterm birth (1). The study results showed that women who ate fish 1 once a week during pregnancy had a 13% lower risk of preterm birth than women who rarely ate fish (less than once a week). In addition, women with a higher intake of fish during pregnancy gave birth to neonates with a higher birth weight of up to 15.2 g. The most pronounced effect on birth weight was observed for higher intakes of fatty fish types containing higher amounts of omega-3 fatty acids.
The researchers concluded that these findings support the need for public health advice to promote fish consumption in pregnant women in accordance with country-specific restrictions regarding fish species known to have high concentrations of pollutants, such as dioxins, mercury and other heavy metals. Fish is a rich source of nutrients, such as omega-3 fatty acids, selenium, iodine, and vitamin D, which are considered to be beneficial for fetal growth and development (2). Because the synthesis of most nutrients in the fetus and placenta is low, maternal intake is critical for their supply to the unborn. Earlier results from prospective cohort studies on the relation between fish intake during pregnancy and fetal growth have been inconclusive. The divergent results may indicate that there is a differential influence by different types or constituents of fish on fetal growth and birth size.