Umbilical discord

Townsend Letter for Doctors and Patients,  Oct, 2006  by Alan Gaby

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In high-risk pregnancies, modern obstetrical care can be life-saving. For low-risk pregnancies, on the other hand, studies indicate that outcomes are at least as good as and possibly better with midwife-supervised, out-of-hospital birth than with obstetrician-supervised, hospital birth. Conventional obstetrics has been criticized for intervening unnecessarily with a natural process, sometimes converting a low-risk situation into one of higher risk and greater morbidity.

For example, women in labor are encouraged to relieve their pain with an epidural block. This procedure can slow the progress of labor, thereby increasing the likelihood of Caesarean section. Epidural blocks can also cause fevers, resulting in the administration of potentially toxic antibiotics to mothers and the unnecessary treatment of newborns for an infections they do not have, with all the associated financial and emotional costs. Epidural blocks have also been shown to delay the onset of successful breastfeeding.

Episiotomies are also frequently performed, though less so than in the past, despite strong evidence that these procedures do more harm than good. (1,2) Fetuses undergo electronic fetal monitoring, an invasive procedure for which there is little evidence of benefit and some evidence of harm. (3,4) Infants are often separated from their mother immediately after birth, during the critical time of bonding and breastfeeding initiation that may determine the ultimate success or failure of breastfeeding. And to add insult to lactational injury, many hospitals provide mothers with free samples of infant formula (donated by the formula manufacturers), which makes it even easier for them not to breastfeed their babies and gives the message that hospitals support bottle-feeding.

Conventional medicine has a long history of being slow to change. However, one simple change that could easily be made--delaying the clamping of the umbilical cord after the baby is born--could have a profound positive effect on the health of infants.

At the time the baby is born, the placenta contains a relatively large amount of blood. If the cord is allowed to remain open, much of this blood is delivered to the baby through the umbilical cord. The volume of this placental "transfusion" amounts to approximately 40 ml of additional blood per kg of body weight. (5) This blood provides about 75 mg of extra iron, an amount sufficient to meet the baby's iron needs for more than three months. Iron deficiency is one of the most common nutritional problems during the first year of life. In addition to being a component of hemoglobin, iron is essential for brain development. A deficiency of iron during this critical period can result in permanent impairment of brain function. (6)

The delivery of highly oxygenated fetal hemoglobin from the placenta to the baby may also have a favorable effect on the infant's health in the early postnatal period. In addition, since Mother Nature went to the trouble of putting stem cells in cord blood, she probably intended for the newborn to receive as many of them as possible.

In a recent study, 476 normal-weight full-term infants born in Mexico City, Mexico, were randomly assigned to delayed clamping (two minutes after delivery of the infant's shoulders) or early clamping (ten seconds after delivery). (5) At six months of age, infants who had delayed clamping had a significantly higher mean serum ferritin concentration (50.7 mcg/L vs. 34.4 mcg/L; p = 0.0002). In addition, significantly fewer infants in the late-clamping group than in the early-clamping group had iron deficiency or iron-deficiency anemia at age six months. The beneficial effect of delayed clamping was significantly greater for infants born to mothers with a low ferritin level at delivery, breastfed infants not receiving iron-fortified milk or formula, and infants born with birthweight between 2,500g and 3,000g.

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Midwives have traditionally delayed cord-clamping until the cord stops pulsing or for at least three minutes after delivery. Obstetricians, on the other hand, frequently clamp the cord immediately, so that the baby can be whisked off to be assessed, weighed, and readied for whatever emergency interventions might become necessary. Ironically, it would seem that a newborn would be less likely to require emergency measures, were it allowed to receive all the blood that nature had intended for it. It is time for early cord-clamping to be relegated to the dustbin of medical history, where it would join blood-letting, that ancient practice of which it is eerily reminiscent.

Alan Gaby, MD

Notes

1. Boschert S. Episiotomies do more harm than good. Fam Pract News. 1995(Nov. 15):35.

2. Argentine Episiotomy Trial Collaborative Group. Routine vs. selective episiotomy: A randomised controlled trial. Lancet. 1993;342:1517-1518.

3. Shy KK, et al. Effects of electronic fetal-heart-rate monitoring, as compared with periodic auscultation, on the neurologic development of premature infants. N Engl J Med. 1990;322:588-593.