Management of Placental Transfusion to Neonates After Delivery

Abstract

This review summarizes high-quality evidence supporting delayed umbilical cord clamping to promote placental transfusion to preterm and term neonates. In preterm neonates, delayed cord clamping may decrease mortality and the need for blood transfusions. Although robust data are lacking to guide cord management strategies in many clinical scenarios, emerging literature is reviewed on numerous topics including delivery mode, twin gestations, maternal comorbidities (eg, gestational diabetes, red blood cell alloimmunization, human immunodeficiency virus [HIV] infection, and severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] infection) and neonatal complications (eg, fetal growth restriction, congenital heart disease, and the depressed neonate). Umbilical cord milking is an alternate method of rapid placental transfusion, but has been associated with severe intraventricular hemorrhage in extremely preterm neonates. Data on long-term outcomes are discussed, as well as potential contraindications to delayed cord clamping. Overall, delayed cord clamping offers potential benefits to the estimated 140 million neonates born globally every year, emphasizing the importance of this simple and no-cost strategy.

Fig. 1.

Delayed umbilical cord clamping recommendations by various organizations. The vertical axis shows duration of delay between birth and umbilical cord clamping. The recommendations for vigorous and nonvigorous neonates (preterm and term) are aligned under the respective legends. There is significant variability in these recommendations. ILCOR, International Liaison Committee on Resuscitation; UCM, umbilical cord milking; GA, gestational age; ACNM, American College of Nurse Midwives; NICE, National Institute for Health and Care Excellence; RCOG, Royal College of Obstetricians and Gynaecologists; ERC, European Resuscitation Council Guidelines; WHO, World Health Organization; PPV, positive pressure ventilation; SOGC, Society of Obstetricians and Gynaecologists of Canada; ACOG, American College of Obstetricians and Gynecologists; AAP, American Academy of Pediatrics; NRP, neonatal resuscitation program; AHA, American Heart Association.

Fig. 2.

Speculative pathogenesis of umbilical cord milking associated severe intraventricular hemorrhage (sIVH) in extremely preterm neonates. After vaginal delivery, uterine contractions propel blood toward the neonate. Umbilical cord milking will enhance umbilical venous return to the right atrium. Because most of the extremely preterm neonates do not have established lung ventilation soon after birth, pulmonary vascular resistance (PVR) and right ventricular pressure remain high, diverting most of umbilical venous return to the left ventricle (LV), thereby increasing LV preload and increasing LV output to the ascending aorta. Milking and uterine contractions increase resistance in the descending aorta. High PVR leads to right-to-left shunt at the patent ductus arteriosus (PDA) level. Fluctuant increase in ascending aorta flow is mostly directed to the cerebral circulation due to high PVR and resistance in descending aorta. Chorioamnionitis and inflammatory mediators along with extreme prematurity contribute to fragility of germinal matrix vasculature precipitating sIVH. PA, pulmonary artery. Courtesy of Satyan Lakshminrusimha. Used with permission.

Fig. 3.

Factors determining placental transfusion and benefits and risks of delayed cord clamping (DCC). Uterine contractions, mode of delivery, time from birth to cord clamp, and possibly gravity and the neonate’s spontaneous respirations may influence the volume of placental transfusion. Benefits of DCC are shown on the right side of the diagram. Hct, hematocrit; SpO₂, oxygen saturation by pulse oximetry; PVR, pulmonary vascular resistance; PDA, patent ductus arteriosus; IVH, intraventricular hemorrhage. Courtesy of Satyan Lakshminrusimha. Used with permission.

Fig. 4.

Oxygen saturations (preductal: median or mean) after early cord clamping (ECC) or delayed cord clamping (DCC) in various studies with vaginal deliveries. Closed circles depict DCC, and open squares depict ECC. The blue area represents the preductal oxygen saturation (SpO₂) values recommended by American Academy of Pediatrics (AAP)/American Heart Association (AHA) Neonatal Resuscitation Program.