Problems and abnormalities A number of abnormalities can affect the umbilical cord, which can cause problems that affect both mother and child: •
Umbilical cord compression can result from, for example, entanglement of the cord, (which is the wrapping of the umbilical cord around the fetal neck) but these conditions do not always cause obstruction of fetal circulation. •
Velamentous cord insertion •
Single umbilical artery •
Umbilical cord prolapse •
Vasa praevia Clamping and cutting The cord can be clamped at different times; however, delaying the clamping of the umbilical cord until at least one minute after birth improves outcomes as long as there is the ability to treat the small risk of
jaundice if it occurs. Clamping is followed by cutting of the cord, which is painless due to the absence of
nerves. The cord is extremely tough, like thick
sinew, and so cutting it requires a suitably sharp instrument. While umbilical severance may be delayed until after the cord has stopped pulsing (one to three minutes after birth), there is ordinarily no significant loss of either venous or arterial blood while cutting the cord. Current evidence neither supports, nor refutes, delayed cutting of the cord, according to the
American Congress of Obstetricians and Gynecologists (ACOG) guidelines. There are umbilical cord clamps which incorporate a knife. These clamps are safer and faster, allowing one to first apply the cord clamp and then cut the umbilical cord. After the cord is clamped and cut, the newborn wears a plastic clip on the navel area until the compressed region of the cord has dried and sealed sufficiently. The length of umbilical left attached to the newborn varies by practice; in most hospital settings the length of cord left attached after clamping and cutting is minimal. In the United States, however, where the birth occurred outside of the hospital and an
emergency medical technician (EMT) clamps and cuts the cord, a longer segment up to in length is left attached to the newborn. The remaining umbilical stub remains for up to ten days as it dries and then falls off.
Early versus delayed clamping A
Cochrane review in 2013 came to the conclusion that delayed cord clamping (between one and three minutes after birth) is "likely to be beneficial as long as access to treatment for jaundice requiring phototherapy is available". In this review delayed clamping, as contrasted to early, resulted in no difference in risk of severe maternal
postpartum hemorrhage or neonatal mortality, and a low
Apgar score. On the other hand, delayed clamping resulted in an increased birth weight of on average about 100 g, and an increased
hemoglobin concentration of on average 1.5 g/dL with half the risk of being iron deficient at three and six months, but an increased risk of
Jaundice requiring
phototherapy. In the same committee statement, ACOG also recognize several other likely benefits for preterm infants, including "improved transitional circulation, better establishment of red blood cell volume, and decreased need for blood transfusion". In January 2017, a revised Committee Opinion extended the recommendation to term infants, citing data that term infants benefit from increased hemoglobin levels in the newborn period and improved iron stores in the first months of life, which may result in improved developmental outcomes. ACOG recognized a small increase in the incidence of jaundice in term infants with delayed cord clamping, and recommended that policies be in place to monitor for and treat neonatal jaundice. ACOG also noted that delayed cord clamping is not associated with increased risk of postpartum hemorrhage. Several studies have shown benefits of delayed cord clamping: A meta-analysis Although there is higher hemoglobin level at 2 months, this effect did not persist beyond 6 months of age. Not clamping the cord for three minutes following the birth of a baby improved outcomes at four years of age. A delay of three minutes or more in umbilical cord clamping after birth reduce the prevalence of anemia in infants. Negative effects of delayed cord clamping include an increased risk of
polycythemia. Still, this condition appeared to be benign in studies. Infants whose cord clamping occurred later than 60 seconds after birth had a higher rate of
neonatal jaundice requiring
phototherapy. The umbilical cord pulsating is not a guarantee that the baby is receiving enough oxygen.
Umbilical nonseverance Some parents choose to omit cord severance entirely, a practice called "
lotus birth" or umbilical nonseverance. The entire intact umbilical cord is allowed to dry and separates on its own (typically on the 3rd day after birth), falling off and leaving a healed umbilicus. The
Royal College of Obstetricians and Gynaecologists has warned about the risks of infection as the decomposing placenta tissue becomes a nest for infectious bacteria such as
Staphylococcus. In one such case, a 20-hour-old baby whose parents chose UCNS was brought to the hospital in an agonal state, was diagnosed with
sepsis and required an antibiotic treatment for six weeks.
Umbilical cord catheterization As the umbilical vein is directly connected to the central circulation, it can be used as a route for placement of a venous catheter for infusion and medication. The umbilical vein catheter is a reliable alternative to percutaneous peripheral or central venous catheters or intraosseous cannulas and may be employed in resuscitation or intensive care of the newborn.
Blood sampling From 24 to 34 weeks of gestation, when the fetus is typically viable, blood can be taken from the cord in order to test for abnormalities (particularly for
hereditary conditions). This diagnostic
genetic test procedure is known as
percutaneous umbilical cord blood sampling.
Storage of cord blood The blood within the umbilical cord, known as
cord blood, is a rich and readily available source of primitive,
undifferentiated stem cells (of type
CD34-positive and
CD38-negative). These cord blood cells can be used for
bone marrow transplant. Some parents choose to have this blood diverted from the baby's umbilical blood transfer through early cord clamping and cutting, to freeze for long-term storage at a
cord blood bank should the child ever require the cord blood stem cells (for example, to replace
bone marrow destroyed when treating
leukemia). This practice is controversial, with critics asserting that early cord blood withdrawal at the time of birth actually increases the likelihood of childhood disease, due to the high volume of blood taken (an average of 108ml) in relation to the baby's total supply (typically 300ml). The
American Academy of Pediatrics has stated that cord blood banking for self-use should be discouraged (as most conditions requiring the use of stem cells will already exist in the cord blood), while banking for general use should be encouraged. In the future, cord blood-derived embryonic-like stem cells (CBEs) may be banked and matched with other patients, much like blood and transplanted tissues. The use of CBEs could potentially eliminate the ethical difficulties associated with
embryonic stem cells (ESCs). While the American Academy of Pediatrics discourages private banking except in the case of existing medical need, it also says that information about the potential benefits and limitations of cord blood banking and transplantation should be provided so that parents can make an informed decision. In the United States, cord blood education has been supported by legislators at the federal and state levels. In 2005, the National Academy of Sciences published an Institute of Medicine (IoM) report which recommended that expectant parents be given a balanced perspective on their options for cord blood banking. In response to their constituents, state legislators across the country are introducing legislation intended to help inform physicians and expectant parents on the options for donating, discarding or banking lifesaving newborn stem cells. Currently 17 states, representing two-thirds of U.S. births, have enacted legislation recommended by the IoM guidelines. The use of cord blood stem cells in treating conditions such as brain injury and Type 1 Diabetes and hearing loss. Cord blood stored with private banks is typically reserved for use of the donor child only. In contrast, cord blood stored in public banks is accessible to anyone with a closely matching tissue type and demonstrated need. The use of cord blood from public banks is increasing. Currently it is used in place of a bone marrow transplant in the treatment of blood disorders such as leukemia, with donations released for transplant through one registry, Netcord.org, passing 1,000,000 as of January 2013. Cord blood is used when the patient cannot find a matching bone marrow donor; this "extension" of the donor pool has driven the expansion of public banks.
Cancer-causing toxicants in human umbilical cords In multiple American and international studies,
cancer-causing chemicals have been found in the blood of umbilical cords. These originate from certain plastics, computer circuit boards, fumes and synthetic fragrances among others. Over 300
chemical toxicants have been found, including
bisphenol A (BPA),
tetrabromobisphenol A (TBBPA),
Teflon-related
perfluorooctanoic acid,
galaxolide and
synthetic musks among others. The studies in America showed higher levels in
African Americans,
Hispanic Americans, and
Asian Americans due, it is thought, to living in areas of higher pollution. ==In other animals==