The Relevant Relationship Between Umbilical Cord Blood Gas and Acid Base Analysis and Dynamic Thiol (Sh)/Disulphide (S-S) Balance in Neonatal Babies with Different Perinatal Risks and Newborn Diseases

 Oxidative stress is a pathogenic stress factor in preterm infants. Dynamic thiol/disulphide balance has a critical role in antioxidant defense, detoxification, apoptosis, transcription and cellular signal transport mechanisms. Oxidant/antioxidant balance state is a process beginning before birth and premature infants are especially vulnerable to oxidative stress.

 In this study, we aimed to evaluate dynamic thiol/disulphide homeostasis by umbilical blood gas analysis, compare term and preterm infants, evaluate its relation with Apgar score, perinatal risks with mother and occurrence of NEC (necrotizing enterocolitis), sepsis and ROP (Retinopathy of Prematurity).

 A total of 108 (51 female and 57 male) newborn infants were included in this prospective cohort study. Of them, 31 were term and 77 were preterm. Demographic variables, Apgar score, NEC, sepsis and ROP intervention data were collected. Disulfide, native thiol, total thiol, index 1 (disulphide/native thiol × 100), index 2 (disulphide/total thiol × 100) and index 3 (native thiol/total thiol × 100) were calculated. Serum total ischemic modified albumin (IMA) and albumin were measured. Bloodgas analysis was performed within 2 minutes following birth.

 Preterm infants had lower disulphide levels and index 1 and 2 ratios, but higher index 3 ratios. Acidotic infants, index 1 and 2 and disulphide levels were higher and index 3 was lower than patients with normal pH. Disulphide, index 1 and 2 were lower in patients taken to NICU (Neonatal Intensive Care Unit) compared to ones who were not, whereas index 3 values were higher, twenty one patients (19.4%) with scores < 7 had higher index 3 values at 5th minute. Disulphide levels, index 1 and 2 levels were lower in patients with NEC and index 3 levels were higher. Index 3 ratios were higher in septic infants. Index 3 was higher in patients born from preeclamptic mothers compared to ones without preeclampsia. Albumin levels were higher in patients with maternal placental anomalies.

 We believe that evaluation of thiol-disulphide homeostasis in preterm and term infants may be demonstrative for oxidant capacity of the newborn, hence the oxidative stress.