Delayed Cord Clamping at Birth May Reduce Neonatal Anemia

News Author: Laurie Barclay, MD
CME Author: Penny Murata, MD

April 20, 2006 — Delayed cord clamping at birth reduces neonatal anemia, according to the results of a randomized trial reported in the April issue of Pediatrics.

"The umbilical cord is usually clamped immediately after birth," write José M. Ceriani Cernadas, MD, from the Hospital Italiano de Buenos Aires in Argentina, and colleagues. "There is no sound evidence to support this approach, which might deprive the newborn of some benefits such as an increase in iron storage.... Iron deficiency early in life may have pronounced central nervous system effects such as cognitive impairment; iron deficiency is also the main cause of anemia, one of the most serious conditions in childhood, especially in developing countries."

In 2 obstetrical units in Argentina, 276 neonates born at term without complications to mothers with uneventful pregnancies were randomized to cord clamping within the first 15 seconds (group 1), at 1 minute (group 2), or at 3 minutes (group 3) after birth.

At 6 hours after birth, mean venous hematocrit values were 53.5% in group 1, 57.0% in group 2, and 59.4% in group 3. Statistical analyses showed equivalent results among groups because the hematocrit increase in neonates with late clamping was within the prespecified physiologic range.

The prevalence of anemia, defined as hematocrit less than 45%, was significantly lower in groups 2 and 3 than in group 1. The prevalence of hematocrit greater than 65% was similar in group 1 (4.4%) and in group 2 (5.9%) but significantly higher in group 3 (14.1%) than in group 1. Other neonatal outcomes and maternal postpartum hemorrhage were not significantly different in the 3 groups.

"Delayed cord clamping at birth increases neonatal mean venous hematocrit within a physiologic range," the authors write. "Furthermore, this intervention seems to reduce the rate of neonatal anemia. This practice has been shown to be safe and should be implemented to increase neonatal iron storage at birth."

The authors recommend controlled follow-up studies of the relationship between delayed cord clamping and the presence of anemia and iron status in infants.

"Another benefit of delayed clamping would be the increase of hematopoietic stem cells transfused to the newborn, which might play a role on different blood disorders and immune conditions," the authors conclude. "The advantages of umbilical cord clamping at least at 1 minute after birth could decrease the prevalence of iron-deficiency anemia in the first year of life, especially in populations with limited access to health care."

United Nations Children's Fund (UNICEF) Argentina supported this study. The authors have disclosed no financial relationships.

Pediatrics. 2006;117:e779-e786

Learning Objectives for This Educational Activity

Upon completion of this activity, participants will be able to:

• Compare the effect of early vs late umbilical cord clamping on neonatal venous hematocrit.
• Describe the effect of timing of umbilical cord clamping on clinical outcomes in term newborns and maternal postpartum hemorrhage.
  

Clinical Context

It is common practice to clamp the umbilical cord immediately, within 15 seconds, after birth. According to an observational study by Saigal and Usher in the 1977 issue of Biology of the Neonate, delayed umbilical cord clamping could increase the risk for polycythemia, respiratory problems, and hyperbilirubinemia. However, in a systematic review by Van Rheenen and Brabin in the March 2004 issue of the Annals of Tropical Paediatrics, they reported that late umbilical cord clamping helps to reduce iron deficiency anemia in infants.

The current study is a prospective, randomized, controlled trial to determine the effect of early vs delayed umbilical cord clamping on venous hematocrit and clinical outcomes in the term neonate as well as maternal postpartum blood loss.

Study Highlights

• 267 neonates who met enrollment criteria (uneventful cephalic vaginal or cesarean delivery; term singleton; no maternal clinical disease or complications; no evidence of congenital malformations or intrauterine growth restriction) were randomized to 1 of 3 different cord-clamping time intervals.
  
• 93 neonates had early cord clamping within first 15 seconds; 91 neonates had delayed cord clamping at 1 minute; 92 neonates had delayed cord clamping at 3 minutes.
  
• Baseline characteristics were similar: maternal age, parity, gestational age, antenatal visits, maternal anemia, cesarean delivery rates, third-stage active management, maternal hematocrit before birth, and newborn weight..
  
• At clinician's discretion, newborns assigned to delayed clamping group instead underwent early clamping if there was no spontaneous breathing in the first 10 seconds, major congenital malformation, birth weight less than the tenth percentile, or tight nuchal cord.
  
• Primary outcome measure of newborn venous hematocrit at 6 hours of age was not significantly different for the groups: 53.5% for early clamping group; 57.0% for 1-minute group; 59.4% for 3-minute group.
  
• At 6 hours, anemia prevalence (venous hematocrit less than 45%) was higher in early clamping group (8.9%) vs 1-minute group (1%; P = .034) and 3-minute group (0%; P = .003)
  
• At 6 hours, polycythemia prevalence (hematocrit greater than 65%) was higher in 3-minute group vs early group (14.1% vs 4.4%; P =.039), but similar for 1-minute group (5.5%) and early group. None were symptomatic..
  
• At 24 to 48 hours, venous hematocrit values were similar for the 3 groups. Anemia prevalence was higher in the early group (16.8%) vs 1-minute group (2.2%; P = .0014) and 3-minute group (3.3%; P = .0027).. Polycythemia prevalence was similar for the 3 groups.
• There were no significant differences for other secondary outcome measures: plasma bilirubin levels at 24 to 48 hours, neonatal morbidity (respiratory distress, tachypnea, grunting, jaundice, seizures, sepsis, necrotizing enterocolitis), mortality (none), neonatal intensive care unit admission, length of hospital stay, disease up to 1 month of age, weight or rate of breast-feeding at 1 month, maternal postpartum blood-loss volume, and maternal hematocrit level at 24 hours postpartum.
  

Pearls for Practice

• In term newborn infants, delayed umbilical cord clamping at 1 or 3 minutes after birth results in decreased prevalence of anemia at 6 hours and at 24 to 48 hours of age vs early cord clamping; the difference in hematocrit levels was not significant.
  
• In term newborn infants, delayed vs early umbilical cord clamping has no effect on newborn clinical outcomes or maternal postpartum hemorrhage.
  
  
  
  
  
  Saludos Cordiales
  Dr. José Manuel Ferrer