Clinical Content June 2021

Cord Clamping

By Stephanie R. Martin, DO

As Medical Director of Clinical Concepts in Obstetrics, Dr. Stephanie R. Martin consults for hospitals and aids them in developing obstetric intensive care programs. Specializing in medical and surgical complications in pregnancy as well as critical care obstetrics, Dr. Martin has spoken for Symposia Medicus since 2008. Here, she shares her expertise on and insights into the benefits of delayed cord clamping.     

What is delayed umbilical cord clamping and why has it become so popular? During the 20th century, early or immediate cord clamping became common practice, despite evidence that delaying may benefit the neonate. A variety of contributing factors may have influenced this transition. In the 1930s, cord blood began to be recognized as a possible source for blood transfusions. Additionally, early clamping of the cord became more common in the days before Rhogam in efforts to minimize the amount of antibody-laden blood from returning to the neonate and potentially causing erythroblastosis fetalis. In another example of unintended consequences, the introduction of the Apgar score itself may have contributed to the universal practice of early cord clamping. In the original 1953 publication, Dr. Virginia Apgar suggested that the initial score be performed at 60 seconds of life, after clamping of the cord. In fact, all cases of “natural childbirth” were excluded from the study as leaving the cord intact was felt to contaminate the sterile field. The rise of cesarean births may also have contributed to early or immediate cord clamping, as delaying cord cutting was perceived to distract from the surgical procedure and potentially increase the risk of maternal hemorrhage.

In recent years, evidence has been mounting that supports a more physiologic approach to clamping of the umbilical cord. It is estimated that 80–100mL of blood transfers from the placenta to the newborn in the first three minutes after birth, with the majority of the transfer occurring with the first few breaths. Delayed cord clamping is commonly defined as clamping of the umbilical cord 30-60 seconds after birth. Studies have demonstrated benefit from delayed cord clamping in both term and preterm infants. Term infants have improved hemoglobin levels and iron stores at six months of age. Iron deficiency has a detrimental effect on neurodevelopment. However, delayed cord clamping in term infants may lead to higher rates of jaundice. The favorable impact of delayed cord clamping on outcomes of preterm infants is more pronounced. This practice has been associated with decreased mortality, as well as decreased rates of intraventricular hemorrhage, necrotizing enterocolitis, and need for transfusion.

As a result of these findings, multiple medical societies have modified their guidance on the topic in recent years. The American College of Obstetrics and Gynecology (ACOG) and the American Academy of Pediatrics (AAP) recommend delayed cord clamping for vigorous term and preterm infants for at least 30–60 seconds. The World Health Organization (WHO) recommends a delay of at least one minute after birth for all infants who do not require positive pressure ventilation. The Royal College of Obstetricians and Gynaecologists (RCOG) recommends a delay of two minutes, while the American College of Nurse Midwives (ACNM) advises a delay of 2-5 minutes before clamping.

The primary concerns surrounding universal implementation of delayed cord clamping involve the potential for delay in neonatal resuscitation and increase in maternal hemorrhage risk. After birth, warm, oxygenated blood is being infused into the neonate until the connection is severed. Newborn care of the term or preterm infant can be initiated immediately, including stimulation and drying, before clamping the cord. Placing the newborn on the mother’s abdomen for skin-to-skin contact does not appear to negatively impact the volume of blood transfused compared to holding the newborn at the level of the introitus during the delay. However, the decision to delay clamping must take into consideration whether the neonate is most likely to benefit from more aggressive resuscitative efforts that require the cord to be cut early so the neonate may be moved to a warmer.

Delaying clamping of the cord by 30-60 seconds should not interfere with active management of the third stage of labor and does not appear to increase the risk of hemorrhage, decreased postpartum hemoglobin levels, or need for transfusion. If the mother is hemodynamically unstable or requires some other immediate intervention that cannot be safely postponed, then delayed cord clamping would not be recommended.

In summary, a return to a more physiologic approach to cord cutting has been associated with improved outcomes for term and preterm infants without significant negative consequences for the majority of women and babies.

Selected References
  1. Downey CL, Bewley S. Historical perspectives on umbilical cord clamping and neonatal transition. J R Soc Med. 2012;105(8):325-329. doi:10.1258/jrsm.2012.110316
  2. Delayed umbilical cord clamping after birth. ACOG Committee Opinion No. 814. American College of Obstetricians and Gynecologists. Obstet Gynecol 2020;136:e100-6.

Dr. Martin is the Medical Director for Clinical Concepts in Obstetrics. She lives in Scottsdale, Arizona.