The impact of genetic and environmental factors on homocysteine levels in preterm neonates

Background: Hyperhomocysteinemia may be associated with vascular complications in adults. Whereas pediatric thrombosis risk peaks in neonates, data on homocysteine (Hcy) levels assessed in term and preterm infants during the perinatal period are scarce. In the present study, we aimed to establish Hcy reference values for preterm infants and study their potential associations with the early post-natal health status. Plasma Hcy and hematocrit levels and MTHFR polymorphisms (C677T and A1298C substitution) were studied in a large cohort of preterm infants in a tertiary referral medical center during an 18-month period. Data were collected on maternal history and delivery as well as on post-natal complications. Results: The study cohort included 167 infants whose mean gestational age was 30.98±2.34 weeks (range: 26-36 weeks), mean birth weight 1327.6±327g, and mean Hcy level 7.99±3.27 (range: 2.2-21.2)μmol/L. Maternal intake of folic acid was inversely associated with the babies' Hcy levels (P=0.0001). Increased Hcy levels positively correlated with birth weight, gestational age (P<0.005), total number of pregnancies (P=0.012), and presence of MTHFR polymorphism. Higher Hcy levels were associated with feeding (P=0.008), especially total parenteral nutrition (P=0.0001). There was no correlation between Hcy levels and any vascular post-natal complications. Conclusions: During their post-natal hospitalization, preterm infants may have relatively high, that is, within the adult normal range, Hcy levels which are influenced by genetic and environmental factors. Despite the fact that no correlation was found between Hcy levels and post-natal complications, these associations should be further studied.