The relationship between umbilical cord blood vitamin A levels and late preterm infant morbidities: a prospective cohort study.

The aim of this study is to explore the association between umbilical cord blood (UCB) vitamin A levels and late preterm infants morbidities. We conducted a prospective cohort study of 208 late-preterm infants(from 34 0/7 to 36 6/7 weeks gestational age) between January 1, 2014 and June 30, 2015. UCB specimens were collected shortly after birth, and vitamin A levels were determined by enzyme-linked immunosorbent assay. Prevalence of low UCB vitamin A level < 0.7 μmol/L was 37.5% in late preterm infants. In comparison to vaginal delivery, cesarean section was associated with UCB vitamin A level < 0.7 μmol/L (P < 0.001). Nevertheless, UCB vitamin A levels did not correlate with gestational age, birth weight, and gender. UCB vitamin A level < 0.7 μmol/L was not an independent risk factor for hospitalization, oxygen supplementation, hyperbilirubinemia, sepsis, and respiratory distress syndrome.Conclusions: Low umbilical cord blood vitamin A levels are common among late-preterm infants. Cesarean section delivery is associated with low umbilical cord blood vitamin A level. Low umbilical cord blood vitamin A levels at birth do not increase morbidity of late-preterm infants, including hyperbilirubinemia, sepsis, and respiratory distress syndrome. What is Known: • Late preterm infants have a higher morbidity and mortality rates when compared to term infants. • Low plasma vitamin A levels increase the risk of preterm infants' morbidity. What is New: • Late preterm infants commonly have low level of umbilical cord blood vitamin A. • Low umbilical cord blood vitamin A level at birth appears to be not associated with the morbidity of late-preterm infants. • Cesarean section is associated with low umbilical cord blood vitamin A level < 0.7 μmol/L compared with vaginal delivery.