• At full term the umbilical cord has an average length of 55 cm (the usual range is 30-100 cm).
• The outer layer of epithelium is from the amnion, and the Wharton's jelly is the internal mesodermal mass.
• Wharton's jelly, which consists of collagen and hyaluronic acid, some muscle fibers, and water, appears to be responsible for the strength of the umbilical cord. Having a cord with a diameter lower than that of the 10th percentile is a good predictor of perinatal complications (e.g., being small for gestational age, having intrapartum complications).
• The fetus starts with two arteries and two veins; the right vena umbilicalis usually obliterates during the second month. Gastroschisis usually occurs on the right side of the umbilical cord (De Vries, 1980).
• The absence of one umbilical artery occurs in about 1% of pregnancies and, in most cases, is an isolated abnormality.
• The helical course of the umbilical vessels is clearly visible from 7 weeks postconception in 95% of fetuses.
• An umbilical coil is defined as one complete spiral of 360 degrees of the umbilical vessels around each other. Both sinistral and dextral spirals occur. The anterior portion of the sinistral spiral will parallel the left limb of a "V," and the anterior portion of a dextral spiral will parallel the right limb of a "V." It makes no difference from which side one views the cord: a sinistral course will be sinistral whether viewed from the fetal side or from the placental insertion site.
• Sinistral spiraling is four to eight times more common than dextral spiraling, and a mixed pattern of spiraling may also be seen. In 2%-5% of umbilical cords there is no spiraling at all.
• The origin of coiling is unknown.
• The umbilical coiling index (UCI) is the ratio of twists to the length of the cord, irrespective of the direction of coiling. The mean UCI identified in a group of uncomplicated pregnancies (Van Dijk et al., 2002) was 0.17 coils/cm (SD = 0.0009). The 10th and 90th percentiles for the UCI were 0.07 coils/cm and 0.30 coils/cm.
• The anatomy of the umbilical cord is such that blood flow is optimized by the coils in the cord.
• Hypercoiled cords are strongly associated with nuchal cords (cords wrapped 360 degrees around the neck); however, the most important problem of tight nuchal cords is probably not compression of the cord itself but compression of the fetal carotid arteries.
• Undercoiling (UCI below the 10th percentile) is associated with fetal death, spontaneous preterm delivery, trisomies, low 5-minute Apgar score, velamentous cord insertion, single umbilical artery, and dextral coiling.
• Overcoiling (UCI above the 90th percentile) is associated with asphyxia, small-for-gestational-age infants, trisomies, single umbilical artery, and sinistral coiling.

Who suspected that the umbilical cord was so intriguing? Do your own observational study and look for associations between your babies and their umbilical cords like those discussed in the two main sources for this article: De Laat, Franx, Bots, Visser, & Nikkels, 2006, and De Laat, Franx, Van Alderen, Nikkels, & Visser, 2005.
 
References
De Laat, M. W., Franx, A., Bots, M. L., Visser, G. H., & Nikkels, P. G. (2006). Umbilical coiling index in normal and complicated pregnancies. Obstetrics and Gynecology, 107(5), 1049-1055.
 
De Laat, M. W., Franx, A., Van Alderen, E. D., Nikkels, P. G., & Visser, G. H. (2005). The umbilical coiling index: A review of the literature. Journal of Maternal-Fetal and Neonatal Medicine, 17(2), 93-100.
 
DeVries, P. A. (1980). The pathogenesis of gastroschisis and omphalocele. Journal of Pediatric Surgery, 15(3), 245-251.
 
Van Dijk, C. C., Franx, A., de Laat, M. W., Bruinse, H. W., Visser, G. H., & Nikkels, P. G. (2002). The umbilical coiling index in normal pregnancy. Journal of Maternal-Fetal and Neonatal Medicine, 11(4), 280-283.
 
Ruth Evans, who compiled the information for this article, is a neonatal nurse practitioner at Children's Hospital, Aurora, CO, and at North Colorado Medical Center, Greeley, CO.

Steve Biddle, MEd, NANN Director of Education

 

• Recommendations concerning evidence-based practice--Although recommendations concerning evidence-based practice are not a required component of CNE, organizations and faculty members are being encouraged to provide accurate, proven, and safe clinical recommendations.
• Resolution of conflicts of interest--The relationships between faculty and planning committee members and commercial interests are being closely scrutinized. CNE providers must ascertain the extent of these relationships and act to resolve any real or perceived conflict between them and the subject matter being taught; it is no longer acceptable simply to disclose these relationships. The planning committee may have to replace faculty members, limit the content of their presentations, or conduct a peer review of their material during the planning process.
• Transparency of commercial support--Financial and in-kind support of CNE is an effective means by which NANN can provide more cost-efficient education. However, commercial contributions are highly restricted and tightly governed, and they must be reported to learners. An independent relationship among the provider, the learners, and the commercial interest must be maintained.
• Gaps in professional practice--Practice gaps are the differences between existing and best practices, between what is and what should be. CNE must now be linked to the health of the individual, community, or population. Planning committee and faculty members for educational activities are being asked to clearly articulate why this activity is considered necessary and important and how it will improve learners' delivery of care.
• Outcomes measurement--Changes in learners' competence and performance and in patient outcomes as a result of CNE must now be measured. These measurements are directly linked to the identification of gaps in care.

New NANN Board Member Regina Grazel

2010 Nurse in Washington Internship

Newest Position Statements from NANN and NANNP