The Umbilical Cord
Early cord clamping deprives the baby of 54-160 mL of blood, which represents up to half of a baby's total blood volume at birth. "Clamping the cord before the infant's first breath results in blood being sacrificed from other organs to establish pulmonary perfusion [blood supply to the lungs]. Fatality may result if the child is already hypovolemic [low in blood volume]". -Morley, G. (1998, July). Cord closure: Can hasty clamping injure the newborn? OBG Mgmnt: 29-36.
Early clamping has been linked with an extra risk of anemia in infancy. -Grajeda, R. et al. (1997).
Delayed clamping of the umbilical cord improves hematologic status of Guatemalan infants at 2 mo. of age. Am J Clin Nutr 65:425-431.
Premature babies who experienced delayed cord clamping--the delay was only 30 seconds--showed a reduced need for transfusion, less severe breathing problems, better oxygen levels, and indications of probable improved long-term outcomes compared with those whose cords were clamped immediately. -Kinmond, S. et al. (1993). Umbilical cord clamping and preterm infants: A randomized trial. BMJ 306(6871): 172-175.
Some studies have shown an increased risk of polycythemia (more red blood cells in the blood) and jaundice when the cord is clamped later. Polycythemia may be beneficial in that more red cells mean more oxygen being delivered to the tissues. The risk that polycythemia will cause the blood to become too thick (hyperviscosity syndrome), which is often used as an argument against delayed cord clamping, seems to be negligible in healthy babies. -Morley, ibid.
Some evidence shows that the practice of clamping the cord, which is not practiced by indigenous cultures, contributes both to postpartum hemorrhage and retained placenta by trapping extra blood (about 100 mL) within the placenta. This increases placental bulk, which the uterus cannot contract efficiently against and which is more difficult to expel. -Walsh, S. (1968, May 11). Maternal effects of early and late clamping of the umbilical cord. The Lancet: 997.
Clamping the cord, especially at an early stage, may also cause the extra blood trapped within the placenta to be forced back through the placenta into the mother's blood supply during the third stage contractions. This feto-maternal transfusion increases the chance of future blood group incompatibility problems, which occur when the current baby's blood enters the mother's bloodstream and causes an immune reaction that can be reactivated in a subsequent pregnancy, destroying the baby's blood cells and causing anemia or even death. -Doolittle, J. & Moritz, C. (1966). Obstet Gynecol 27:529 and Lapido, O. (1971, March 18). Management of the third state of labour with particular reference to reduction of feto-maternal transfusion. BMJ 721-3.
The above are excerpts from Sarah Buckley's "A Natural Approach to the Third Stage of Labour," Midwifery Today Issue 59
Several types of cord problems can affect blood flow to the baby and cause fetal distress. "Cord nipping" means the cord is being pinched between the head and pelvic bones, causing variable decelerations in the fetal heart tones (FHTs). During first stage, repositioning the mother usually eases pressure on the cord and brings the FHT to normal, but in second stage nipping may easily progress to cord compression. One trick for remedying variable decels in second stage is to gently press on the mother's abdomen where the baby's back is located. This frequently shifts the baby off the cord and improves FHTs.
Cord compression may be due to occult prolapse, meaning that the cord is low in the pelvis and is being compressed by the head as it descends with the force of contractions. If cord compression is severe, bradycardia is likely to develop. There is also a possibility that the FHT will return to normal if the head moves past the cord entirely. Persistent bradycardia constitutes a crisis with very little leeway. Try repositioning the mother and give oxygen by mask at 6 L/min. Check FHT with each contraction. If there is no improvement after four or five contractions, transport to the hospital.
Cord entanglement may inhibit descent and you may hear cord sounds over the FHT. A very tight cord around the neck may also deflex the baby's head. This may result in persistent bradycardia, necessitating transport.
Complete cord prolapse can occasionally be diagnosed by internal exam in the last weeks of pregnancy with the discovery of pulsations at the cervix or through the lower uterine segment that are synchronous with the FHT. This finding necessitates immediate hospitalization and cesarean section.
If the membranes rupture during labor and the cord prolapses, call the paramedics and place the mother in a knees-chest position with your fingers inside her cervix, holding the head up and away from the cord. Place the cord gently back inside the vagina if it is exposed. If there isn't room, wrap it in gauze or a washcloth soaked in warm water with a pinch of salt and cover with a plastic bag. Rough handling of the cord or exposure to air can cause spasm and constriction. If you must transport the mother yourself, lay a chair back-down on the floor and ease her onto it, then lift and tip her slightly backward until her head is lower than her hips. Keep her in this position in the car with fingers inside to alleviate pressure on the cord until the cesarean is performed.
-Elizabeth Davis, Heart and Hands, Celestial Arts 1997