How do animals cut the umbilical cord

Obstetrics: The umbilical cord should not be cut too quickly

If the umbilical cord between mother and child is cut too quickly after birth, the risk of anemia is increased. A possible cause is a suboptimal transfer of haematopoietic stem cells. In a prospective, controlled, randomized study, a team of gynecologists and obstetricians from Uppsala University compared the effect of early versus delayed cutting of the umbilical cord on the iron supply of the child in the 4th month of life and the prevalence of anemia (primary endpoint). Secondary endpoints were the incidence of anemia, polycythemia, hyperbilirubinemia with phototherapy, and respiratory symptoms.

After an uncomplicated pregnancy (gestation period 37 to 41 weeks), 400 children were randomized 1: 1 into one of the two study arms: either cutting the umbilical cord within 10 seconds or at least 180 seconds after delivery. In both groups, the newborn was held 20 centimeters below the vulva for about half a minute immediately after birth and then placed on the mother's stomach.

Four months after delivery there was no statistically significant difference in hemoglobin concentrations between the two groups. But children with late severing of the umbilical cord had an average of 45% higher ferritin concentration (117 µg vs. 81 µg / liter blood; p <0.001) and less often iron deficiency (0.6 vs. 5.7%; p = 0.01). The number needed to treat (NNT) was 20. In the secondary endpoint, there was a statistically significant difference only in neonatal anemia (2 days after birth): 1.2% versus 6.3% in favor of delayed cord removal; NNT: 20). Neonatal icterus did not occur more frequently when the umbilical cord was later clamped.

Conclusion: Waiting at least 3 minutes to cut the umbilical cord has a positive effect on the iron and ferritin concentrations in the child's blood.

"In the guidelines of the German Society for Gynecology and Obstetrics, a waiting time of up to one and a half minutes after vaginal delivery is recommended," comments Dr. med. Markus Valter, senior physician in charge of obstetrics at the University Women's Clinic in Cologne. Often the umbilical cord hardly pulsates at this point.

"There are data that significantly longer waiting times, especially when combined with stroking the umbilical cord, can be associated with an increased risk of neonatal jaundice," explains Valter. "The results of the study indicate, however, that one minute should not be exceeded."

Dr. rer. nat. Nicola Siegmund-Schultze

Andersson O, Hellström-Westas L, Andersson D, Domellöf M: Effect of delayed versus early umbilical cord clamping on neonatal outcomes and iron status at 4 months: a randomized controlled trial. BMJ 2011; 343: doi: 10.1136 / bmj.d7157