Pregnancy is an important stage for every woman, and proper nutrition is of utmost importance for the health of both the mother and the baby. There are several factors that can impact pregnancy outcomes, and one of the most significant is preterm birth.

Preterm birth is defined as the birth of a baby before 37 completed weeks of gestation and is a leading cause of infant mortality and morbidity worldwide.

Preterm birth is a complex and multifactorial condition with various risk factors, including maternal age, smoking, hypertension, stress, and nutritional status.

Poor nutrition during pregnancy can have a significant impact on fetal growth and development, increasing the risk of preterm birth and other adverse pregnancy outcomes.

Fish is an essential component of a healthy diet, providing a rich source of protein, omega-3 fatty acids, and various vitamins and minerals.

There is a growing body of evidence supporting the role of fish intake in the prevention of preterm birth during pregnancy. In this article, we will discuss the impact of fish intake on preterm birth prevention during pregnancy.

Omega-3 Fatty Acids and Preterm Birth

Omega-3 fatty acids are a group of essential fatty acids that are crucial for fetal development, particularly for the development of the brain and the central nervous system.

Fish is a rich source of two types of omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

A large number of studies have investigated the relationship between omega-3 fatty acid intake during pregnancy and the risk of preterm birth.

A meta-analysis of 70 studies found that omega-3 fatty acid supplementation during pregnancy was associated with a 11 percent reduction in the risk of preterm birth (P = 0.03).

Another study conducted in Australia found that women who consumed at least three servings of fish per week during pregnancy had a 14 percent lower risk of preterm birth compared to women who consumed less than one serving of fish per week (P = 0.04).

Methylmercury and Preterm Birth

Methylmercury is a toxic substance that is present in some types of fish, particularly large predatory fish such as shark, swordfish, king mackerel, and tilefish.

Methylmercury can affect fetal neurological development and has been associated with an increased risk of preterm birth.

However, the beneficial effects of omega-3 fatty acids in fish may counteract the negative effects of methylmercury on preterm birth risk.

A prospective cohort study conducted in Canada found that high fish intake (>2 servings/week) during pregnancy was associated with a reduced risk of preterm birth (odds ratio (OR) = 0.66, 95% confidence interval (CI) 0.45-0.98) even in the presence of high mercury levels. Conversely, low fish intake (<1 serving/week) was associated with an increased risk of preterm birth (OR = 1.41, 95% CI 1.01-1.95).

The authors concluded that the beneficial effects of fish intake on preterm birth outweigh the potential risks of methylmercury exposure (source).

Which Types of Fish are Safe to Eat During Pregnancy?

Not all types of fish are safe to eat during pregnancy because some may contain high levels of methylmercury or other harmful substances.

The US Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) recommend that pregnant women and women who may become pregnant consume 8-12 ounces (2-3 servings) of fish per week from the following list of low-mercury fish:.

Salmon
Anchovies
Cod
Catfish
Crawfish
Haddock
Herring
Shrimp
Tilapia

Pregnant women should avoid eating large fish such as shark, swordfish, king mackerel, and tilefish, which are known to contain high levels of methylmercury.

Canned tuna is also safe to eat in moderation, but pregnant women should limit canned white (albacore) tuna to six ounces per week and should avoid raw or undercooked fish and seafood.

Conclusion

The evidence supports the important role of fish intake during pregnancy in the prevention of preterm birth.

Although some types of fish may contain high levels of methylmercury, the beneficial effects of omega-3 fatty acids in fish outweigh the potential risks of methylmercury exposure. Pregnant women should consume low-mercury fish as part of a healthy and balanced diet to promote fetal growth and development and reduce the risk of preterm birth and other adverse pregnancy outcomes.