Prior research has established an association between prenatal maternal consumption of DHA/EPA and longer gestation and higher birth weight but outcomes relating to specific neonatal anthropometrics (such as length and head circumference) are inconsistent, say the authors of a new study published in the American Journal of Obstetrics and Gynaecology.
Therefore, researchers set out to determine if there was a connection between foetus biometric measures and gestational DHA/EPA intake in the first trimester. They found significant growth improvements in foetus abdominal circumference (AC), and AC to head circumference ratio (HC).
“Intriguing, but…”
Vice President of Regulatory and Scientific Affairs at the Global Organisation for EPA and DHA (GOED), Harry Rice, recognises the novel objective of the study and describes the results as “Interesting” but “Underwhelming” as he believes they raise “too many unanswered questions”.
“The reality is that this was an exploratory analysis and requires additional research to confirm what I would call preliminary results.”
He also asserted that the strongest evidence for supplementation is in the ability to lower the risk of preterm delivery and that this should be the primary focus of public policy.
Study program
The study cohort consisted of 1,535 low-risk, racially-mixed pregnant women who were recruited from 12 US clinics.
Participants were enrolled from 8 to 12 weeks gestation. After that, they were randomly assigned to one among four follow-up visits. These visits consisted of five visits each to assess lifestyle, demographic and health characteristics.
Based on self-administered food frequency questionnaires, the average dietary DHA/EPA consumption in the periconception (grams/day), was calculated. Women who didn’t report any first trimester supplementation were classified based upon whether they had met the recommended intake of 0.25 g/d dietary DHA/EPA from supplements or dietary sources.
To determine foetal growth during the first trimester of DHA/EPA supplementation, data on diet intake was collected. Ultrasonographic measurements of foetus were taken at enrolment (8-13 week) and five subsequent visits. The estimated foetus weight (EFW), and the HC:AC (a measure for growth symmetry), were also calculated.
Weekly comparison tests were also conducted where there were significant global differences to assess foetural growth parameters. Pre-term birth was not included.
Clinical importance
DHA/EPA intake led to significant differences in foetus growth, according to research. Improved maternal intake led to higher EFW, AC and HC as well as a better HC-to-AC ratio.
EFW was consistent higher for women who started supplementation at week 19, and statistically significant at the end of pregnancy. Foetus weights were 83 to 132 grams higher than those who received control, which ranged from 38 to 41 weeks.
Analyses also revealed significant increases in biometric measurements of AC in the second trimester (17 week) and HC at the end of the third trimester (30 week). It was also found that women with supplementation had a lower ratio of HC to AC in the latter half of pregnancy than those who received it.
Women who consumed 0.25g/d or more dietary DHA/EPA had a higher foetal BPD at term than women who consumed less than 0.25g/d. The consumption of DHA/EPA was associated with significantly lower risks of small gestational years (SGA). DHA/EPA intake did not affect the gestational length.
The authors’ commented: “Although these are small differences of uncertain clinical significance, the increasing trends in foetal growth, especially the increase in EFW and AC in response to DHA/EPA supplementation, generate interesting hypotheses.”
Positive Trends
Researchers recognized the limitations of their research, which included a lack information on dosage, frequency, and length of supplement intake prior to or during pregnancy.
Furthermore, differences in foetus growth could be due to the overall maternal lifestyle. It is impossible to draw any conclusions about the clinical implications.
They added that given the observational nature of this study, “causality cannot be known”But positive trends can still be used to inform future research.
Source: American Journal of Obstetrics and Gynaecology
Published online August 5, 2022: https://doi.org/10.1016/j.ajog.2022.08.007
‘The association between first trimester omega-3 fatty acid supplementation and fetal growth trajectories’
Authors: Y. Vafai, et al.
