Expecting mothers who take fish oil are less vulnerable to severe pregnancy-related complications like gestational diabetes and pre-eclampsia and are also less likely to have miscarriages, according to scientists from the University of Western Australia.

Earlier in 2012, researchers from the University of Adelaide found that taking fish oil during pregnancy could protect the baby from eczema by strengthening the foetus’ immune system. These babies were also 50% less likely to develop an allergic reaction to eggs before their first birthday.

What’s in fish oil?

Fish oil is a great source of omega-3 polyunsaturated fatty acids — numerous studies have shown that these omega 3s are crucial for the baby’s neurological and early vision development.

Omega-3s are essential fatty acids in that they cannot be synthesised by the body. As such, an adequate intake is required for sufficient production of prostaglandins, hormone-like substances. These prostaglandins help control blood pressure; blood clotting, nerve transmission as well as mediating inflammatory and allergic responses. Prostaglandins are also involved in regulating renal and digestive functions.

Study details

To better understand the mechanisms behind the benefits of fish oil consumption during pregnancy, the researchers investigated the effects of fish oil on pregnant rats. The rats were given either a standard diet or one high in omega-3s from day one of pregnancy.

Study findings

The researchers found that consumption of fish oil during pregnancy increases levels of resolvins in the placenta. Omega-3s are converted to resolvins which may alleviate inflammatory conditions from which about 30% of women suffer during pregnancy.

“Our research is exciting because it suggests that the placenta is capable of converting fish oil to resolvins, which would prevent placental inflammation,” the lead researcher, Megan Hones, told The Daily Telegraph.

“Rates of placental inflammation are very high in pregnancy disorders,” Ms Jones said. “Fish oil should prevent that and limit placental inflammation.”

Fish oil and pregnancy: safety considerations

Not all commercial fish oils are equal; some may even be toxic. So, if you plan to start popping fish oil pills, get your doctor’s advice first. And here are a few tips that will help you select quality fish oil that is safe for both you and your growing baby.

  • Choose omega-3 fish oils not fish liver oils such as cod liver oil. Animal liver is rich in vitamin A, an excess of which can harm your unborn baby.
  • Ask for a Certificate of Analysis (COA) before purchasing the supplement. This is to make sure that the product meets international standards for heavy metals, PCBs, dioxins and other contaminants.
  • The fish oil shouldn’t smell or taste fishy. If it does, then you know that the oil is becoming rancid and is starting to decompose.
  • Avoid oils with artificial flavours. These chemical additives may be harmful for your baby or it could be that these have been added to camouflage the fishy flavour and taste.

What if you don’t want to take supplements?

You can eat oily fish instead but make sure to limit yourself to two portions a week and avoid consuming more than two fresh tuna steaks or four medium-sized, BPA free, tuna cans per week.


Then consider these foods: flax seeds and oil, nuts and seeds. But remember that plant-derived omega-3s are much less bio available.


    Jones et al (2013) Maternal dietary omega-3 fatty acid intake increases resolvin and protectin levels in the rat placenta. J Lipid Res. 54(8):2247-54.

    Palmer et al (2012). Effect of n-3 long chain polyunsaturated fatty acid supplementation in pregnancy on infants’ allergies in first year of life: randomised controlled trial. BMJ. 344:e184.