Effects of delayed cord clamping in intrauterine growth-restricted neonates: a randomized controlled trial.

The time of cord clamping in intrauterine growth-restricted (IUGR) neonates remains an area of uncertainty. This assessor-blinded randomized controlled trial compared the effects of delayed cord clamping (DCC) with early cord clamping (ECC) on the systemic blood flow (SBF) and cerebral hemodynamics in IUGR neonates of gestational age ≥28 weeks, not requiring resuscitation. Eligible newborns were randomized to DCC (cord clamping after 60 s; n=55) or ECC (cord clamping within 30 s; n=55) group immediately after delivery. The primary outcome variable was superior vena cava (SVC) blood flow at 24±2 h. The secondary outcome variables were right ventricular output (RVO), anterior cerebral artery (ACA) blood flow velocity (BFV), superior mesenteric artery (SMA)-BFV and venous hematocrit at 24±2 h, peak total serum bilirubin (TSB), incidences of polycythemia, intraventricular hemorrhage, respiratory distress, feeding intolerance, and necrotizing enterocolitis, outcome, duration of hospital stay, screening audiometry, and serum ferritin levels at the postnatal age of 3 months. Compared to ECC, DCC was associated with significantly higher SVC flow (101.22±21.02 and 81.27±19.12 mL/kg/min, in DCC and ECC groups, respectively; p<0.0001), and significantly increased RVO, SMA-BFV, venous hematocrit, and serum ferritin levels. Though peak TSB was significantly higher with DCC, duration of phototherapy was comparable. ACA-BFV, incidence of polycythemia, and other outcomes were comparable between the groups.Conclusions: DCC was a safe and beneficial intervention in IUGR infants with an improved SBF and SMA-BFV and an increased hematocrit and serum ferritin levels without higher incidences of polycythemia and requirement of phototherapy for significant hyperbilirubinemia.Trial registration: Clinical Trials Registry of India (CTRI/2019/05/018904) What is Known: • Delayed cord clamping (DCC) increases superior vena cava (SVC) blood flow in preterm neonates. • DCC increases hematocrit and serum ferritin in intrauterine growth-restricted (IUGR) neonates, but there may be an associated risk of polycythemia and neonatal hyperbilirubinemia. What is New: • DCC increases SVC blood flow, right ventricular output, superior mesenteric artery blood flow velocity, venous hematocrit, and serum ferritin in IUGR neonates. • Incidences of polycythemia and duration of phototherapy for significant neonatal hyperbilirubinemia do not increase with DCC.