The residual blood from segmental umbilical cord milking in preterm delivery

Umbilical cord milking is an alternative procedure providing blood to infants but there is no study in the proper length of umbilical cord and various gestational age. The aim of this study was to measure the blood volume in the umbilical cord of preterm infants at a certain length and to identify the correlation among blood volume, length, and circumference of umbilical cord, gestational age (GA), birth weight and placenta. Seventy-five pregnant women aged 18 years old and above with 24-36⁺⁶ weeks of gestation were included in this cross-sectional study. After delivery, a 15 to 45 cm of umbilical cord was cut and parameters of umbilical cord were recorded. The mean GA at birth was 241.84 ± 20.06 days. The mean length, diameter, and circumference were 23.31 ± 7.66, 1.10 ± 0.18, and 3.56 ± 0.75 cm, respectively. The mean residual blood volume was 11.58 ± 4.99 mL or 0.50 ± 0.18 mL/cm. Total residual blood volume had a significant positive strong correlation with umbilical cord length (r = 0.720, p < .001). To reduce complications from blood overload, the appropriate blood volume for preterm infant should be calculated from birth weight and umbilical cord length.Impact statementWhat is already known on this subject? The World Health Organisation recommends delayed cord clamping for newborn infants which neonatal resuscitation was not indicated but the majority of preterm infants needed resuscitation. Umbilical cord milking is an alternative procedure providing blood to infants. A small volume transfusion (10-20 m/kg) is commonly used for replacement in preterm neonates. Although there is a concern about the blood volume transferred into infants, blood volume and proper length of umbilical cord have not been thoroughly investigated.What do the results of this study add? In this study, the mean residual blood volume was 0.5 mL/cm and total residual blood volume had a significant positive strong correlation with umbilical cord length. In subgroup of very low birth weight group, the mean residual blood volume was 0.41 mL/cm; however, there was no statistically significant difference from other birth weight groups.What are the implications of these findings for clinical practice and/or further research? The appropriate length of umbilical cord for milking can be calculated from the estimated foetal weight and the mean residual blood volume per length (0.5 mL/cm); nevertheless, the calculation should be used with caution. The further study should investigate in extremely preterm or very low birth weight infants.