Evidence-Based Practices for the Fetal to Newborn Transition

The Timing of Umbilical Cord Clamping

Currently, no formal guidelines about the best timing for umbilical cord clamping exist. Clamping the cord immediately after birth results in a 20% reduction in blood volume for the neonate and up to a 50% reduction in red cell volume.^[28] Several RCTs have indicated that more infants who experience immediate clamping have anemia of infancy compared to infants who had delayed clamping ( Table 1 ). A number of studies have related anemia of infancy, even when treated with iron, with less favorable neurodevelopmental and behavioral outcomes up to age 10.^[29] There are no studies of immediate or delayed cord clamping that follow children beyond 6 months of age.

Since the publication of the last review of the literature on umbilical cord clamping,^[30] one systematic review^[31] and four additional RCTs involving term infants^{[32,33,34,35]} have been published. The four studies, whose subjects included 827 mother-infant pairs, were all conducted in resource-poor countries over the last 4 years. All included women at term with no medical or obstetric complications. Although the findings of each study are slightly different, they all found higher newborn hematocrit and hemoglobin levels within the first 24 hours after birth without adverse outcomes in the infants who experienced delayed cord clamping. Two of the studies found significantly fewer signs of anemia at 3 and 6 months in infants with delayed cord clamping. Synopses of the four studies can be found in Table 1 . The systematic review is discussed below.

Van Rheenen and Brabin^[31] conducted a systematic review of two randomized controlled trials^[34,36] that compared immediate versus delayed cord clamping in term infants to determine the effect on anemia status after 2 months of age. Their secondary objective was to assess the incidence of polycythemia and/or jaundice during the first week of life in infants who experienced delayed cord clamping. The authors found that delayed cord clamping, especially in anemic mothers, increased hemoglobin status and reduced the risk of anemia at 2 to 3 months of age (RR, 0.32; 95% CI, 0.02-0.52). Although infants with delayed clamping had higher hematocrit levels, no reports of symptomatic polycythemia or jaundice were found. The authors stated that delaying clamping may be especially beneficial in developing countries where anemia rates are high.

The current literature refutes the idea that delayed cord clamping causes symptomatic polycythemia and indicates that immediate clamping of the cord may often lead to anemia of infancy.

In addition to anemia, possible neurologic harm from clamping a nuchal cord before birth has been identified.^[37] A recent integrated review of the literature on nuchal cord management found reports showing increased risks to the newborn when the cord was clamped before the shoulders are delivered.^[38] Leaving the cord intact and using the somersault maneuver is recommended especially if shoulder dystocia is suspected. During the somersault maneuver, the infant's head is kept near the perineum as the body delivers so that little traction is exerted on the cord (Figure 1).^[38] Resuscitation at the perineum allows the infant to regain the blood trapped in the placenta and can be accomplished using all the proper tenets of neonatal resuscitation.

Increasing blood volume by delayed clamping should result in the infant receiving a greater allotment of hematopoietic stem cells and red blood cells. Hematopoietic stem cells are pluripotent, meaning that they can develop into many different cell types.^[39] Evidence suggests that hematopoietic stem cells may migrate to and help repair damaged tissue during inflammation and can differentiate into such cells as glia, oligodendrocytes, and cardiomyocytes as needed.^[40] In a rat model of cerebral palsy, half the damaged rats were given human umbilical stem cells within 24 hours of the injury. The infusion of cord blood appeared to prevent development of the rodent version of cerebral palsy, which was clearly evident in the damaged rats who did not get human cord blood.^[41] Yet cord blood harvesting companies advertise cord blood as "medical waste" and encourage parents to collect it at birth. Although cord clamping time is not prescribed in the instructions for cord blood harvesting, the suggestion is that the earlier the cord is clamped, the larger the harvest will be. This practice of cord blood harvesting is not supported by the American Academy of Pediatrics unless there is a clear medical need within the family.^[42] Parents need to be fully informed by providers during pregnancy in order to make sound decisions about storing cord blood.

In summary, the current literature supports a lack of harm for full term infants when cord clamping is delayed up to 10 minutes with the newborn placed on the maternal abdomen or held below the level of the perineum. In addition, the evidence is strong that delayed cord clamping offers full-term infants protection from anemia. Based on the current evidence, the recommendation is to delay cord clamping to prevent anemia of infancy. Also, we recommend that clinicians not cut a nuchal cord before delivery of the shoulders, but instead, use the somersault maneuver to deliver the child and resuscitate at the perineum as necessary.

Keeping infants warm at birth is an essential part of immediate newborn management. Newborns are at risk for heat loss at birth because of their large surface area to mass ratio, minimal subcutaneous tissue, and skin permeability to water. The procedure of skin-to-skin care requires that the bare newborn is placed in direct contact with the mother's bare skin (usually prone). Skin-to-skin care can occur immediately after birth and during the first hour of life. When a newborn is placed skin-to-skin, the woman provides heat directly to her newborn via conduction. Frequently, the newborn is dried completely and a blanket is placed over infant and mother to prevent heat loss through convection and evaporation.

A literature search on the topic of newborn thermoregulation revealed one 2004 Cochrane review, two RCTs, and one observational physiologic study. Only those studies published since the Cochrane review are included in Table 2 .^{[1,43,44,45,46]}

In the term newborn, skin-to-skin care is associated with both short- and long-term benefits. In the short term, the newborn experiences an increase in body temperature when compared to infants cared for in a warmer or dressed and placed in a crib.^[43,47,48] Even when a dressed newborn is with the mother after the initial hour of skin-to-skin contact, Fransson^[45] found less difference between the newborn's core (rectal) temperature and the temperature of the skin when compared to the temperature differential in newborns cared for in a crib. In addition to aiding in maintaining temperature, infants who had skin-to-skin care in the first hour were found to sleep longer, spend more time in a quiet state, and were better organized at 4 hours of age^[46] ( Table 2 ).

Long-term benefits of immediate skin-to-skin contact and suckling during the first hour of life include a longer duration of breastfeeding,^[44] more maternal positive feelings towards child rearing,^[49] and improved scores for maternal affection and maternal attachment.^[1] Carfoot^[43] found that 90% of the mothers who had skin-to-skin care were very satisfied and 87% would prefer skin-to-skin care again, compared to only a 59% satisfaction rating by the mothers in routine care group.

In conclusion, skin-to-skin contact is a safe, inexpensive, and acceptable method of regulating the thermal environment for healthy term newborns. This method can be applied immediately after birth for most newborns. There are short- and long-term benefits for both mother and baby. The most consistent additional effects are increased success and duration of breastfeeding and scores of bonding and attachment. Skin-to-skin should be considered a primary intervention for prevention of neonatal hypothermia. Birthing units that separate mothers and babies with the intention of preventing cold stress unwittingly increase the risk of cold stress, and at the same time deprive the pair of intimacy and bonding while delaying breastfeeding initiation. The evidence suggests that skin-to-skin contact should be the mainstay of newborn thermoregulation.

Most obstetric texts describe clearing the newborn's nose and mouth at birth with a bulb syringe. Table 3 summarizes the findings of several small research studies that have examined the impact of suctioning on newborn respiratory status.^{[50,51,52,53]} All studies were conducted on vigorous term infants and none found any significant differences in health outcomes between infants suctioned and not suctioned. These studies demonstrate no benefits from routine suctioning after birth and support abandoning suctioning as a routine procedure.

Treatments to prevent meconium aspiration syndrome have included amnioinfusion during labor, intrapartum suctioning, and endotracheal intubation and suctioning of infants with meconium-stained fluid. The most recent evidence suggests that these practices are not helpful and do not prevent meconium aspiration syndrome. Table 4 offers the current evidence about these practices.^[54,55,56] A 2006 review^[57] shows no benefit to infants from these practices.

Two classic nonrandomized studies done in the 1970s^[58,59] suggested that suctioning the airway before the birth would decrease the incidence of morbidity and mortality associated with meconium aspiration syndrome. Subsequent studies comparing DeLee suctioning with bulb suctioning found no differences in the incidence and severity of meconium aspiration syndrome, respiratory rates, or Apgar scores between the infants who had suctioning either before delivery of the head or after birth.^[60,61,62] In 2004, the Meconium Study Network^[55] conducted a large multicenter RCT comparing outcomes of vigorous infants with meconium staining, with or without suctioning on the perineum ( Table 4 ). No difference was found between the two groups for any outcomes, even when analyzing the subgroup with thick meconium. This suggests that intrapartum suctioning does not prevent meconium aspiration syndrome. Similarly, no benefit for the prevention of meconium aspiration syndrome has been found following amnioinfusion^[54] or from endotracheal intubation and suctioning of vigorous term infants.^[56] These practices should not be used to prevent meconium aspiration syndrome.^[57]

It has been suggested that gastric suctioning of the newborn might prevent regurgitation and aspiration of meconium or other stomach contents. A MEDLINE search on gastric suctioning of the newborn revealed only one study relevant to this review.

Widstrom^[63] studied the effect of gastric suction on newborn circulation and subsequent feeding behavior. Healthy, term newborns were randomly assigned to have gastric suction (n = 11) or no gastric suction (n = 10). At birth, the newborns were dried and placed on the mother's chest. No suctioning of the airway was done, and all infants began to breathe spontaneously. The umbilical cord was clamped and cut between 60 and 90 seconds after birth. Pulse and blood pressure were recorded every minute from 5 to 10 minutes of age. Between the first two blood pressure recordings, infants in the suction group had a #8 suction catheter inserted through the mouth into the stomach, and the contents were aspirated. The procedure lasted approximately 20 seconds. The infants were maintained in a prone position on their mother's chests and were observed for 3 hours. While the two groups did not differ in average heart rate, one infant in the suction group had an episode of bradycardia, and infants in the suction group experienced an increased blood pressure when the catheter was withdrawn. Defensive motions were observed in nine of the suctioned infants. Suckling was delayed until 62 minutes in the suction group versus 55 minutes in the no suction group. There was also a greater lag in hand-to-mouth movements in the suction group (P = .005). This small study found harm and no benefit from gastric suctioning, indicating that it should not be used in the routine care of the neonate.

J Midwifery Womens Health. 2007;52(3):262-272. © 2007 Elsevier Science, Inc.

Cite this: Evidence-Based Practices for the Fetal to Newborn Transition - Medscape - May 01, 2007.