according to data from a meta-analysis of 18 studies.
Previous research suggests that low birth weight is protective against the development of atopic dermatitis, said Tingting Zhu, PhD, of West China Second University Hospital, Chengdu, and colleagues.
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Preterm birth (before 37 completed weeks’ gestation) was divided into subgroups of extremely preterm (less than 28 weeks’ gestation), very preterm (28 weeks’ to less than 32 weeks’ gestation), and moderate/late preterm (32 weeks’ gestation to less than 37 weeks’ gestation).
In an analysis based on gestational age, children had a significantly reduced risk of eczema if they were very preterm (relative risk, 0.77; 95% confidence interval, 0.70-0.84, P less than .01; adjusted RR, 0.73; 95% CI, 0.64-0.82; P less than 0.01), compared with children born full term. The association between eczema and preterm birth was no longer significant among children born moderately preterm, Dr. Zhu and associates reported.
The reasons for the impact of very preterm birth on eczema are unclear, but maturation of the stratum corneum at 29-37 weeks’ gestational age could play a role, the researchers noted. Also, limited microflora in very preterm infants could affect acquiring immune tolerance and lead to reduced risk of eczema. The study was limited by several factors, including variations in gestational age and inconsistent assessments of eczema among the studies.
However, the large sample size lends strength to the results, and further studies are needed to explore how the environment, nutrition, immune system development, and skin barrier function impact the risk of eczema in very preterm infants, Dr. Zhu and associates said.
The researchers had no relevant financial disclosures. The researchers had no financial conflicts to disclose. The study was funded in part by the National Science Foundation of China, the Ministry of Health of China, and various other grants.
SOURCE: Zhu T et al. J Amer Dermatol. 2018. doi: 10.1016/j.jaad.2017.12.015.