Relationship between vitamin D levels in mother’s blood and neonatal umbilical cord with jaundice in neonates
Authors: Sadr Zahra , Nourbakhsh Mona , Bakhshizade Majid , Mokhtari Forough , Biglari Abhari Maryam 
Published: May 2022

Introduction: In neonates, jaundice is the result of an imbalance between the production and conjugation of bilirubin. Overall, about 60% of full-term neonates experience jaundice in the first week of life. Metabolism of bilirubin and vitamin D occurs in two separate pathways, but because one stage of their production happens in liver, they may affect each other. Objectives: Diagnostic and therapeutic assays are based only on the opinion of obstetricians and gynecologists. The possible results of this study may help to explain preventive methods. In this study, we will evaluate the relationship between serum levels of vitamin D in the mother’s blood and the baby’s umbilical cord with the occurrence of neonatal jaundice. Patients and Methods: This prospective study (cohort) was performed on 110 mothers and their newborns in Firoozabadi hospital in Shahr-e Ray. The sampling method was non-probability convenience. Data including maternal age, nationality, gravidity, gestational age, maternal diseases such as chronic the liver and kidney disease, diabetes mellitus, hypertension and the use of anticonvulsant drugs were obtained from the maternity delivery records and mothers who did not meet the inclusion criteria were excluded at first. Maternal blood samples during labor and neonatal umbilical cord samples were used for assaying the serum levels of 25-hydroxy vitamin D, calcium (Ca) and phosphorus (P), alkaline phosphatase (ALP). All neonates visited for jaundice on days 7 and 14 after birth and tested for bilirubin levels if jaundice was observed. Results: There was no significant difference between neonates with normal and abnormal vitamin D levels in terms of jaundice on day 7 (P=0.571). Additionally, there was not a significant relationship between mothers with normal and abnormal vitamin D levels in terms of jaundice on day 7 in their neonates (P=0.587). However, a statistically significant relationship between normal vitamin D levels in mothers with jaundice in their neonates on day 14 (P=0.003) was detected. There was a significant relationship between normal maternal vitamin D with the incidence of neonatal jaundice on day 14 (relative risk = 0.32). In addition, evaluation of the relationship between normal and abnormal vitamin D levels in neonates with 14th day jaundice revealed no statistically significant relationship between the two groups of normal and abnormal (P=0.1). Mean serum ALP concentration in mothers of neonates who did not develop jaundice was significantly higher than mothers of neonates with severe jaundice (bilirubin >15 mg/ dL) (P=0.02). First minute Apgar score in neonates who had no jaundice or developed mild jaundice was significantly higher than neonates with severe jaundice (bilirubin >15 mg/dL) (P=0.026). Conclusion: Overall, in this study, no significant relationship was observed between neonatal 7th day jaundice with maternal and neonatal vitamin D levels. There was a significant relationship between maternal normal serum vitamin D levels with neonatal 14th day jaundice.