DHA levels modulate immune response during pregnancy, study finds

24 Jan 2022 --- A 1,000 mg dosage of docosahexaenoic acid (DHA) in pregnant women affects the inflammatory immune responses linked to childbirth. This is according to a study conducted by several US universities that found this supplementation may reduce preterm birth risk as DHA has anti-inflammatory properties.

The research was funded by the National Institutes of Health’s (NIH) Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and Nationwide Children’s Hospital.

During pregnancy and childbirth, the maternal immune system experiences modifications. Early inflammatory immune responses, while necessary for the start of labor, are linked to a higher risk of preterm birth and other complications.

The authors point out that more research into these connections is needed.

Investigating inflammatory immune responses
Researchers discovered that a larger daily intake of DHA affects the levels of two proteins – the receptor for advanced glycosylation end products (sRAGE) and interleukin 6 (IL-6) – which could explain why it can reduce preterm birth risk.

Researchers measured five proteins involved in inflammatory immune responses.

They assessed the levels of these proteins and DHA levels in blood samples obtained at study enrollment – between 12 and 20 weeks of pregnancy – and delivery from 902 participants, of whom 437 took 200 mg per day of DHA and 465 received 1,000 mg per day.Scientists investigated whether taking more than the 200 mg dose included in many prenatal vitamins could reduce the probability of preterm delivery.

Other characteristics that potentially influence preterm birth risk were taken into account, including DHA level at study enrolment, smoking history, race and ethnicity, history of preeclampsia (pregnancy-related high blood pressure issues) and BMI.

These study results follow previous research that also examined the interaction between preterm birth rates and DHA supplementation.

Preterm birth and sRAGE levels
Participants who had greater sRAGE levels at the start were more likely to have longer pregnancies and deliver at term. sRAGE levels typically drop between early pregnancy and labor and multiple studies have reported low sRAGE levels in persons who had spontaneous preterm births.

The scientists observed smaller decreases in sRAGE levels between study enrollment and delivery for participants receiving 1,000 mg per day of DHA, compared to those receiving 200 mg per day.

This suggests that the higher DHA dose supports a more robust production of sRAGE, which could decrease inflammation during pregnancy.

Higher IL-6 levels at birth were linked to a higher risk of delivering after 37 weeks of pregnancy in the study population. Those who received the greater DHA dose showed a significantly bigger increase in IL-6 levels than those who took the lower amount between enrolment and delivery.

Reducing preterm births
A separate Lancet-published study revealed that pregnant women in the US should take DHA supplements to prevent preterm birth risk.

When ingested before and during pregnancy, a blend of myo-inositol (a type of sugar), probiotics, riboflavin, zinc and vitamins D, B6, and B12 can reduce the risk of premature birth, Nestlé research found.

Edited by Nicole Kerr