Omega-3 fatty acid supplementation in pregnancy-baseline omega-3 status and early preterm birth: exploratory analysis of a randomised controlled trial.
Level 2 - randomized trial
Exploratory subgroup/interaction analysis of a randomized controlled trial
PubMed 32034969 · doi:10.1111/1471-0528.16168
What was done
This was an exploratory secondary analysis of the ORIP multicenter randomized controlled trial across six Australian hospitals. Maternal capillary whole blood was collected at approximately 14 weeks' gestation from women with singleton pregnancies. Total blood lipid fatty acids were quantified using gas chromatography, and interaction tests assessed whether baseline polyunsaturated fatty acid status modified the effect of omega-3 supplementation versus control on early preterm birth (<34 weeks' gestation).
What was found
Low total omega-3 status in early pregnancy (≤4.1% of total fatty acids) was associated with higher early preterm birth risk. In this subgroup, omega-3 supplementation reduced early preterm birth compared with control (0.73% vs 3.16%; relative risk [RR] 0.23, 95% CI 0.07–0.79). Conversely, in women with higher baseline status (>4.9%), supplementation increased early preterm birth compared with control (2.20% vs 0.97%; RR 2.27, 95% CI 1.13–4.58).
Why it matters
This suggests that omega-3 supplementation benefits pregnant women with low baseline omega-3 levels but may increase early preterm birth risk in those who are already replete, arguing against blanket supplementation.
Limits
The total sample size, subgroup sizes, and specific supplement dosage were not provided in the abstract. Findings stem from an exploratory secondary analysis and require prospective validation.
Cited by
- context A red blood cell DHA level of 3% or lower is associated with high risk for preterm birth, whereas levels above 5% are not high risk.