Can Omega-3 supplement help prevent babies from being born too early?

“India carries the world’s largest burden of preterm birth, and its population appears to carry the genetic variant that raises the risk most often. DHA is safe, cheap and available everywhere. The obvious next step is a trial in India,” said the study’s senior authors, Prof Kumar Kothapalli and Prof Tom Brenna.

What did the study find?

The study suggests that a common genetic variant may influence the risk of early preterm birth — delivery before 34 weeks of pregnancy. That’s because a woman’s genetic makeup influences her DHA requirements during pregnancy. Among women carrying the variant, a higher daily dose of DHA was associated with a lower risk of early preterm birth.

How does the genetic variant affect pregnancy?

The variant is found in the fatty acid desaturase (FADS) genes, which help regulate the body’s production of arachidonic acid (ARA), an omega-6 fatty acid.

ARA contributes to the production of prostaglandin E2, a hormone-like substance involved in initiating labour. Women carrying the insertion (I) version of the variant tend to produce more ARA, which is associated with inflammatory processes.

DHA, found in oily fish and fish oil, may counter some of the effects of ARA. This offers a possible biological explanation for why higher DHA intake could reduce the risk of early preterm birth in women carrying the variant.

Could DHA supplements help prevent early preterm birth?

The researchers screened 10,487 women for eligibility and analysed genetic and pregnancy data from 761 pregnant women in the United States. The women had been randomly assigned to receive either 200 mg or 1,000 mg of DHA daily.

Among women carrying at least one copy of the I variant, the rate of early preterm birth fell from 4.3% in the lower-dose group to 1.1% in the higher-dose group — a relative reduction of about 75%.

However, among women who did not carry the variant, the higher dose was associated with a greater likelihood of pregnancy continuing beyond 40 weeks.

The results suggest that DHA requirements may differ according to genetic makeup, underscoring the need to identify who is most likely to benefit from higher doses. DHA is included in some prenatal supplements and infant foods in the United States, but its use specifically to prevent preterm birth requires further investigation.

Why are the findings relevant to India?

Previous research suggests that the I variant is unusually common among people of South Asian ancestry, possibly because of natural selection over many generations. It may therefore be more prevalent in South Asian populations than in several other ancestry groups.

This raises an important question: could Indian women, among whom the variant may be common, benefit from higher DHA supplementation during pregnancy? Given India’s enormous preterm birth burden, an effective, inexpensive nutritional intervention could have significant public health implications.

But the findings are not yet grounds for changing antenatal care in India. The trial was conducted in the United States and did not include Indian participants. A clinical trial in India is needed to establish whether the variant is similarly associated with early preterm birth in Indian women and whether higher-dose DHA can reduce that risk.

If confirmed, the findings could pave the way for a targeted, affordable approach to prevention.