Effect of timing of cord clamping on hemodynamic and oxygenation parameters in moderate to late-preterm neonates

This prospective observational study will be conducted after obtaining approval from the Institutional Ethics Committee and the Institute Review Board. The study will also be registered with the Clinical Trial Registry of India prior to initiation. Written informed consent will be obtained antenatally from pregnant women admitted for anticipated preterm delivery. Participants will be assured that their participation is voluntary and that they may withdraw at any time without affecting clinical care. All moderate to late preterm neonates meeting the inclusion criteria with gestational age of 32 weeks to 36 weeks plus 6 days, and born in the hospital who do not require resuscitation at birth will be enrolled in the study. All enrolled neonates will undergo delayed cord clamping as per the routine practices of the attending obstetric team. Based on the timing of cord clamping, neonates will be observed and categorized into one of three groups: • Early Cord Clamping : Cord clamped at less than 60 seconds • Short-duration delayed cord clamping 60 to 120 seconds, and • Extended-duration delayed cord clamping more than equal to 120 seconds. The timing of cord clamping will be documented using a standardized stopwatch protocol. Immediately after birth, prior to cord clamping, the neonate will be placed either on the mother’s abdomen or a sterile surface at the level of the placenta. A pulse oximeter with a neonatal probe will be applied to the neonate’s right wrist , and continuous monitoring will be done using a standardized pulse oximetry device to record: • Heart rate • Preductal oxygen saturation • Perfusion index • Pleth variability index These parameters will be recorded at 1 minute intervals from 1 to 10 minutes of life. To ensure accuracy in recording the exact time of cord clamping and the values of key physiological parameters, videographic recording of the monitor screen only will be done in all enrolled neonates. The recording will capture real-time values of perfusion index , pleth variability index , heart rate , and oxygen saturation during the immediate postnatal period. No part of the mother or the birthing field will be included in the video recording, thus ensuring complete privacy and dignity of the laboring mother. The video footage will be reviewed independently by two trained investigators for verification and extraction of time synchronized data. This approach will minimize observer bias and improve the accuracy and consistency of data collection. All neonates will receive routine postnatal care including early skin-to-skin contact and initiation of breastfeeding as per Essential Newborn Care protocols. A functional echocardiography will be performed by trained neonatologists within the first 12 to 24 hours of life using a standardized protocol. Parameters to be assessed include: • Superior Vena Cava  flow • Left Ventricular Output  • ACA PSV, RI • SMA PSV, RI Image acquisition and measurements will follow a standardized protocol aligned with international neonatal echocardiography guidelines. A second blinded reviewer will independently analyse all the scans to assess interobserver variability.Additional clinical and demographic data including gestational age, birth weight, gender, APGAR scores, mode of delivery, and relevant antenatal risk factors will be collected using a pre-designed and validated case record form. Routine neonatal management will continue as per unit protocol without interference from the study procedures.