Delayed cord blood sampling unreliable

Article

Current guidelines that state that blood from a clamped umbilical cord can be used for blood samples up to 1 hour after delivery should not be applied to tests for lactate as a marker for prenatal hypoxia.

Current guidelines that state that blood from a clamped umbilical cord can be used for blood samples up to 1 hour after delivery should not be applied to tests for lactate as a marker for prenatal hypoxia.

Scottish researchers analyzed 20 arterial samples and 18 venous samples from placentas of infants delivered by elective cesarean section. They paired samples of blood from clamped and unclamped cords at 0, 20, 40, and 60 minutes for lactate, base excess, pH, and PCO2.

In samples analyzed immediately, arterial and venous lactate levels were significantly higher than they were at 20 minutes in both clamped and unclamped vessels. In clamped vessels, pH did not change over the course of an hour, but in unclamped vessels, it changed significantly. There were also significant changes in base excess in both the clamped and unclamped samples.

Armstrong L, Stenson B. Effect of delayed sampling on umbilical cord arterial and venous lactate and blood gases in clamped and unclamped vessels Arch Dis Child Fetal Neonatal Ed. 2006;91:F342-F345.

Newsletter

Get the latest clinical updates, case studies, and expert commentary in obstetric and gynecologic care. Sign up now to stay informed.

Recent Videos
Neal Barnard, MD, FACC, highlights AMA's new breast cancer prevention guidelines | Image Credit: pcrm.org.
Zachary Wagner, PhD, discusses the harms of bias in reproductive care | Image Credit: ornsife.usc.edu.
Ciera Kirkpatrick, PhD, shows how TikTok is transforming cervical cancer awareness | Image Credit: linkedin.com.
Maria Gallo, PhD, discusses high attendance at crisis pregnancy centers | Image Credit: © x.com.
Related Content
© 2025 MJH Life Sciences

All rights reserved.