Eczema risk lower in very preterm babies
Infants born very preterm appear to have a lower risk of eczema, according to a recent meta-analysis. However, further studies are required to confirm the findings and to understand the underlying mechanisms.
Pooled data from 18 studies (n=2,163.737 individuals) that provided unadjusted data showed that there was a significant correlation between the risk of eczema and preterm birth (relative risk [RR], 0.87; 95 percent CI, 0.83–0.91; p<0.001). These findings had moderate heterogeneity (p=0.17).
This was confirmed in subsequent meta-analysis of adjusted data, which were provided in 11 studies (n=2,115,274 individuals). Controlling for important confounders such as sex, parental history and maternal smoking showed that preterm birth remained significantly correlated with eczema risk, with moderate heterogeneity (adjusted RR, 0.81; 0.73–0.91; p<0.001; p=0.05 for heterogeneity).
Subgroup analysis according to gestational age revealed that the protective effect was significant only in those born very preterm (adjusted RR, 0.73; 0.64–0.82; p<0.01). The relationship was attenuated among those who were born moderately preterm (adjusted RR, 0.86; 0.73–1.01; p=0.07).
“Although the number and nature of the potential confounders varied across the studies included, most only adjusted for the important confounders. Residual confounding factors should be considered when interpreting the findings,” said researchers.
For the current meta-analysis, researchers extracted observational studies from the databases of Embase, Web of Science, Cochrane Library and PubMed. Studies that examined the correlation between preterm birth and eczema were eligible, while those that focused on allergic disease without specifications for eczema were excluded.