An ethical and interpretive analysis of

Early versus delayed umbilical cord clamping in preterm infants (Cochrane Review)

Rabe H, Reynolds G, Diaz-Rossello J

In seven randomized controlled trials, 297 preterm infants were subjected to human experimentation. The conclusion was that delayed clamping SEEMED TO reduce the risk of anemia (blood transfusion) and of intraventricular hemorrhage. All these trials should have complied with the Nuremberg code of 1948 and the World Medical Association's ethical restrictions for medical research on human subjects (Helsinki 1964.) Regarding informed consent, six of the seven trials appear to be in gross violation.

In January 1993, Kinmond et al. published such a study on 36 preterm infants, 17 in the delayed clamping (DCC) group had gravity assisted placental transfusion for 30 seconds, and 19 infants in an immediately clamped (ICC) group. The DCC group needed ZERO blood transfusions, ICC group 23 ml/Kg. DCC group needed an average of 3 days of supplemental oxygen compared to 10 days for the ICC group. Three ICC infants developed chronic lung disease versus NONE of the DCC group. Two infants from each group sustained IVH, however, the ICC infants developed enlarged ventricles (loss of brain tissue); the DCC infants did not. The Cochrane reviewers could have reached their conclusion from the Kinmond study alone; Kinmond concluded," This intervention at preterm deliveries produces clinical and economic benefits."

These 1993 results should have guided subsequent researchers in an ethically correct direction. Prospective parents of preemies should have had Kinmond's results explained to them, in words that they could understand, to give informed consent for possible ICC; informed parental choice regarding ICC injuries eliminates the random control group of ICC babies. The ethical researcher needs a new rational control cohort.

Kinmond's rationale was to supply the neonate with some placental transfusion, holding the child 20 cms below the vulva for 30 seconds before terminating placental function. The unsurprising result was that placental transfusion obviated the need for blood transfusion, and that hypovolemic / ischemic complications (shock lung, anemia, germinal matrix hemorrhagic infarction) were ameliorated.

The Cochrane reviewers address only the time of clamping delay; however, a preemie held 20 cms above the level of the placenta for 60 seconds before clamping (DCC) could be severely compromised by gravitational blood loss into the placenta. DCC per se thus becomes a very questionable benefit, contradicting Cochrane Reviewers' conclusion. The critical factor that assures the health and welfare of the preemie is the amount of placental transfusion that occurs before the cord is clamped, regardless of the timing.

The new control cohort should consist of babies that close the cord vessels physiologically - no cord clamp used - and if need be, the child should go to the nursery with cord and placenta intact. A preemie attached to a functioning placenta by a vigorously pulsating cord does not require "resuscitation;" it will reflexively switch from placental life support to its own life support systems physiologically, and it will clamp its own cord at precisely the correct, physiological time. Kinmond comments, "We did not time the onset of respiration in relation to cord clamping, but many infants in the regulated group were already crying." Oxygenated blood constricts and closes the umbilical arteries.

There are no reported complications of delivering preemies in this manner, and ethical researchers should have no difficulty in obtaining ethical informed consents for a very large control cohort with which to compare Kinmond's method.

George Malcolm Morley MB ChB FACOG

I certify that I have no affiliations with or involvement in any organisation or entity with a direct financial interest in the subject matter of my criticisms.