Investigation of Newborn Renal Functions in Pregnancy with Isolated Oligohydramnios

Aim: This study aimed to investigate whether isolated oligohydramnios has an impact on renal function in term neonates.Materials and Methods: Sixty term pregnancies were evaluated—30 diagnosed with isolated oligohydramnios (AFI ≤ 5 cm) and 30 with normal amniotic fluid volume. Amniotic fluid index was measured using the four-quadrant technique. Immediately after birth, cord blood was analyzed for blood urea nitrogen (BUN), creatinine, sodium, and potassium. Urine samples were tested for beta-2 microglobulin.Results: Neonatal serum BUN, creatinine, sodium, and urinary beta-2 microglobulin levels did not differ significantly between groups (p > 0.05). Potassium was significantly higher in the oligohydramnios group (5.44 ± 1.05 mmol/L) compared with controls (4.91 ± 0.87 mmol/L, p = 0.0377). Potassium levels correlated negatively with the 5-minute Apgar score (r = –0.279, p = 0.03) and AFI (r = –0.349, p = 0.006), and positively with non-reactive NST (r = 0.396, p = 0.002). ROC analysis showed potassium had moderate predictive value for oligohydramnios (AUC = 0.678, p = 0.018) and strong predictive value for non-reactive NST (AUC = 0.835, p = 0.002).Conclusion: While isolated oligohydramnios did not appear to impair early neonatal renal function overall, elevated potassium levels and their association with fetal distress indicators suggest that potassium may be a useful biochemical marker for intrauterine stress.