The umbilical cord: normal parameters

Umbilical Artery Thrombosis Causing Fetal Distress: A Case Report

The umbilical cord (UC) is vital to maintain blood circulation between the mother and the growing fetus, which is sometimes disrupted. The umbilical artery thrombosis (UAT) is an infrequent complication of pregnancy that can lead to extreme perinatal outcomes, ranging from intrauterine growth restriction stillbirth to neonatal death. The prenatal diagnosis of UAT is essential and sometimes challenging to detect in clinical practice. Once it is detected, the emergent delivery through a cesarean section is considered after the steroidal lung maturity of the fetus. We report a primigravida diagnosed with this rare pregnancy complication, the UAT at delivery, along with the nuchal cord and abnormally coiled UC. The patient had an uneventful course of pregnancy except for the premature rupture of membranes and continuous fetal distress in the second stage of labor. As the labor progression was optimal, and prioritizing the patient's desire, she was vigilantly observed under the premise of continuous electronic fetal monitoring (EFM) to facilitate any emergency, ultimately resulting in the spontaneous vaginal delivery of an alive and healthy baby boy. The fetal distress detected through EFM is an indicator of several stressors predisposing the fetus to some unknown danger that carries an increased risk of perinatal mortality. Based on our experience, it is suggested that radiologists should routinely conduct UC sonographic studies on regular antenatal scans; obstetricians should also have a brief and precise awareness of the critical lifesaving sonographic parameters to measure. The UAT, nuchal cord, and abnormal UC coiling, as found in our case, are all rare factors and related to some extent of fetal morbidity and mortality; once such complications are prenatally suspected, one should manage it through close monitoring and timely decision of appropriate delivery time.

Giant umbilical cord in a normal preterm infant: a case report and review of the literature

BACKGROUND

Giant umbilical cord, defined as a cord diameter of more than 5 cm, is an extremely rare malformation. There are few case reports of giant umbilical cord often associated with patent urachus duct or cystic malformation. These cases are usually managed by surgical excision and repair of patent urachus or cyst resection.

CASE PRESENTATION

We report the case of a 1-day-old Iranian boy with giant umbilical cord detected postnatally. The pregnancy course was uneventful, except for preterm premature rupture of the membrane and preterm delivery. There was no relevant family history. The patient was delivered by vaginal delivery with a good Apgar score. On clinical examination, the umbilical cord was very thick (about 6 cm in diameter), and huge fluctuating Wharton's jelly was observed. Other organs were normal. During the hospital stay, the patient did not develop any complications except borderline hyperbilirubinemia, which improved with conventional phototherapy. Since the umbilical cord had no discharge and was dried, the newborn was discharged with advice for cord drying care.

CONCLUSION

The newborn was well, and the dried umbilical stump was detached after 32 days, leaving a granulomatous structure without discharge. The patient was followed up for 4.5 months and had no problems except delayed separation of the umbilical cord.

A misdiagnosed case of a 150-cm umbilical cord coiled twice around the fetal neck with a true cord knot: A rare Syrian case report

The normal umbilical cord is a crucial component during pregnancy, but sometimes it could become compromised due to some abnormalities such as excessive long umbilical cord, and though they usually end up with a healthy baby, they may lead to severe consequences. Excessive long umbilical cords are found in 4% of pregnancies and represent a risk factor for nuchal cords and true knots. We report a case of a 37-year-old Syrian pregnant woman who presented to the hospital at 37 weeks of gestation asking for a C-section for a fear of ambiguous ultrasound findings that have been interpreted as fetal malformation. At delivery, a healthy baby was born with a 150-cm umbilical cord, a true knot, and double-looped nuchal cords; the formation of the loops and the knot had been attributed to the elongated cord. Besides, ultrasound imaging could sometimes be deceptive and lead to unnecessary interventions; therefore, cord anomalies should always be kept in mind because they do not always represent a justification for a C-section.

Current Perspectives of Prenatal Sonography of Umbilical Cord Morphology

The umbilical cord constitutes a continuation of the fetal cardiovascular system anatomically bridging between the placenta and the fetus. This structure, critical in human development, enables mobility of the developing fetus within the gestational sac in contrast to the placenta, which is anchored to the uterine wall. The umbilical cord is protected by unique, robust anatomical features, which include: length of the umbilical cord, Wharton’s jelly, two umbilical arteries, coiling, and suspension in amniotic fluid. These features all contribute to protect and buffer this essential structure from potential detrimental twisting, shearing, torsion, and compression forces throughout gestation, and specifically during labor and delivery. The arterial components of the umbilical cord are further protected by the presence of Hyrtl’s anastomosis between the two respective umbilical arteries. Abnormalities of the umbilical cord are uncommon yet include excessively long or short cords, hyper or hypocoiling, cysts, single umbilical artery, supernumerary vessels, rarely an absent umbilical cord, stricture, furcate and velamentous insertions (including vasa previa), umbilical vein and arterial thrombosis, umbilical artery aneurysm, hematomas, and tumors (including hemangioma angiomyxoma and teratoma). This commentary will address current perspectives of prenatal sonography of the umbilical cord, including structural anomalies and the potential impact of future imaging technologies.

Umbilical Cord Diameter at the Junction of the Body Wall in the Newborn. Is It a Biomarker for Congenital Umbilical Hernia?

INTRODUCTION

The aim is to obtain normal newborn umbilical cord diameters for use it in the evaluation of congenital umbilical hernia.

MATERIALS AND METHODS

The umbilical cord diameter (UCD) at the abdominal wall, maternal age, birth weight, gestational age at birth, birth height, head, chest and abdominal circumferences, and the time of measurement after birth was noted.

RESULTS

Mean ± standard deviation and median (minimum-maximum) values of the UCD were 9.9 ± 1.9 mm, 10.0 (5-16 mm), respectively. There was a significance for a positive low correlation between birth height and UCD (p = .039, r = .143). No other birth parameter had a significant correlation with UCD. The gender of the newborn (p = .95) and the type of delivery (p = .056) did not affect UCD.

CONCLUSION

These data may be used in determining the normality of UCD, which could be helpful in the evaluation of umbilical hernias.

Prenatal MRI evaluation of limb-body wall complex

BACKGROUND

The sonographic (US) features of limb-body wall complex have been well documented; however the literature regarding the findings on MRI in limb-body wall complex is scant.

OBJECTIVE

To characterize the prenatal MRI features of limb-body wall complex.

MATERIALS AND METHODS

We performed a retrospective review of all MRI scans of fetuses diagnosed with limb-body wall complex at our institution from 2001 to 2011. Fetuses without correlating US scans or follow-up information were excluded. Three pediatric radiologists blinded to the specific US findings reviewed the prenatal MRIs. Images were evaluated for the organ location and attachment, the body part affected, characterization of the body wall defect, and spinal, limb and umbilical cord abnormalities.

RESULTS

Ten subjects met inclusion criteria. MRI was able to detect and characterize the body part affected and associated abnormalities. All fetuses had ventral wall defects, a small thorax and herniated liver and bowel. The kidneys were extracorporeal in three cases. The extruded organs were attached to the placenta or the uterine wall in all cases. Abnormal spinal curvatures of various degrees of severity were present in all cases. Eight cases had a short, uncoiled cord. Limb anomalies were present in 6 of the 10 cases.

CONCLUSION

We illustrate the common fetal MRI findings of limb-body wall complex. The prenatal diagnosis of limb-body wall complex and the differentiation of this defect from treatable abdominal wall defects are crucial to providing appropriate guidance for patient counseling and management.

In vitro method for real-time, direct observation of cell-vascular graft interactions under simulated blood flow

In the development of engineered vascular grafts, assessing the material's interactive properties with peripheral blood cells and its capacity to endothelialize are important for predicting in vivo graft behavior. Current in vitro techniques used for characterizing cell adhesion at the surface of engineered scaffolds under flow only facilitate a terminal quantification of cell/surface interactions. Here, we present the design of an innovative flow chamber for real-time analysis of blood-biomaterial interactions under controllable hemodynamic conditions. Decellularized human umbilical veins (dHUV) were used as model vascular allografts to characterize platelet, leukocyte, and endothelial cell (EC) adhesion dynamics. Confluent EC monolayers adhered to the lumenal surface of the grafting material were flow conditioned to resist arterial shear stress levels (up to 24 dynes/cm(2)) over a 48 h period, and shown to maintain viability over the 1 week assessment period. The basement membrane was imaged while whole blood/neutrophil suspensions were perfused across the HUV surface to quantify cell accumulation. This novel method facilitates live visualization of dynamic events, including cell adhesion, migration, and morphological adaptation at the blood-graft interface on opaque materials, and it can be used for preliminary assessment of clinically relevant biomaterials before implantation.

Birth outcome measures and maternal exposure to heavy metals (lead, cadmium and mercury) in Saudi Arabian population

This cross-sectional study was conducted to assess the association between exposure to heavy metals (lead, cadmium and mercury) during pregnancy and birth outcomes in 1578 women aged 16-50 years who delivered in Al-Kharj hospital, Saudi Arabia, in 2005 and 2006. The levels of lead, cadmium and mercury were measured in umbilical cord blood, maternal blood and the placenta. Outcome variables were anthropometric measures taken at birth, along with the risk of being small-for-gestational age (SGA). We selected the 10th percentile as the cutoff for dichotomizing measures of birth outcome. Cadmium, despite its partial passage through the placenta had the most prominent effect on several measures of birth outcome. After adjustment for potential confounders, logistic regression models revealed that crown-heel length (p=0.034), the Apgar 5-minute score (p=0.004), birth weight (p=0.015) and SGA (p=0.049) were influenced by cadmium in the umbilical cord blood. Significant decreases in crown-heel length (p=0.007) and placental thickness (p=0.022) were seen with higher levels of cadmium in maternal blood. As placental cadmium increased, cord length increased (p=0.012) and placental thickness decreased (p=0.032). Only lead levels in maternal blood influenced placental thickness (p=0.011). Mercury in both umbilical cord and maternal blood was marginally associated with placental thickness and placental weight, respectively. Conversely, placental mercury levels significantly influenced head circumference (p=0.017), the Apgar 5-minute score (p=0.01) and cord length (p=0.026). The predictions of these models were further assessed with the area under the curve (AUC) of the receiver operating curves (ROCs), which were modest (larger than 0.5 and smaller than 0.7). The independence of gestational age or preterm births on the observed effect of metals on some measures of birth outcome, suggested detrimental effects of exposure on fetal development. The magnitude of the estimated effects might not necessarily be of clinical significance for infants but may have a considerable public-health relevance given the high prevalence of exposure to heavy metals. Further research should be conducted to confirm these findings and to evaluate their long-term risks, if any.

Polycyclic aromatic hydrocarbons (PAHs) as determinants of various anthropometric measures of birth outcome

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants that are known to induce oxidative stress. There have been several reports about the link between PAH exposure and complications in pregnancy. This cross-sectional study was conducted to: (1) measure the levels of benzo(a)anthracene (BaA), chrysene (Ch), benzo(b)fluoranthene (BbF), benzo(a)pyrene (BaP), and dibenzo(a,h)anthracene (DBahA) in placentas and maternal and -umbilical cord blood obtained at delivery from 1578 women between June 2005 and 2006 in the area of Al-Kharj, Saudi Arabia; (2) assess their influence on various anthropometric measures of birth outcome taking into consideration the carcinogenic properties of these PAHs; and (3) determine the degree of PAH-related oxidative DNA damage and birth outcome. Among the five tested PAHs, only BaP was carcinogenic; therefore, the levels of the other four probable or possible carcinogenic PAHs (BaA, Ch, BaF, and DBahA) were summed as ∑4-PAHs. Levels of 1-hydroxypyrene (1-HP) were determined in maternal urine samples as a biomarker of PAH internal dose. Urinary cotinine (COT) was measured as an index of smoking. The following markers of oxidative stress were selected: malondialdehyde (MDA) in cord (C-MDA) and maternal (M-MDA) serum and 8-hydroxy-2-deoxyguanosine (8-OHdG) in maternal urine. None of the tested PAHs was found in maternal or cord blood. However, all five PAH compounds were detected in placentas; Ch was the highest (6.582 μg/kg dry wt.), and BaA was the lowest (0.236 μg/kg dry wt.). The mean concentration of urinary 1-HP found in this study was 0.216 ± 0.856 μg/g Cr. After adjusting for gestational age and other confounding variables, regression models revealed an inverse relationship between placental weight, cord length and placental BaP. A similar trend was observed between cord length and ∑4-PAHs in placental tissues. Urinary 1-HP, though, cannot be used as an unequivocal biomarker of PAH exposure, but it can be an appropriate indicator of exposure to environmental tobacco smoke (ETS). The data demonstrate that ETS exposure (as measured by urinary COT) may adversely affect birth outcome as shown by reduced head circumference, birth weight, and birth length, as well as increased cephalization index. The positive relationship between 8-OHdG levels and 1-HP in urine provides evidence of an oxidative stress mechanism. Although this study provides no direct evidence of an association between PAH exposure and DNA damage, increased oxidative stress in the form of lipid peroxidation significantly affected various birth measures. Therefore, there is a need for studies regarding PAH exposure and its associated biological effects to determine the extent of potential fetal damage as well as possible long-term effects, such as cancer.

Coiling characteristics of umbilical cords in breech vs. vertex presentation

OBJECTIVE

To compare selected umbilical cord parameters, especially cord coiling, between breech and vertex presentations.

METHODS

We prospectively collected umbilical cords from uncomplicated breech and vertex obtained during elective term cesarean deliveries. We compared various cord parameters between the two groups as well as data regarding obstetric history and pregnancy outcome.

RESULTS

We evaluated 55 umbilical cords from breech and 55 from vertex deliveries. Umbilical cord length (56.93 cm vs. 63.95 cm, P=0.05), number of coils (5.1+/-0.4 vs. 11.7+/-0.6, P<0.0001) and umbilical cord index (UCI) (0.09 coils/cm vs. 0.18 coils/cm, P<0.0001) were all significantly lower for breech presentations and remained significant following multivariate analysis.

CONCLUSION

We document significant differences in umbilical coiling and the UCI between breech and vertex presentation. The precise reason for these differences is still unclear.

Current management of umbilical abnormalities and related anomalies

Prenatally, the umbilicus is of paramount importance, providing the gateway between the mother and the fetus. As the fetus becomes increasingly autonomous at the end of the second month of fetal life, the connections (vitelline, urachal) diminish in significance and involute. Disturbances in this process can result in a wide variety of abnormalities, ranging from relatively minor defects identified at birth (umbilical granulation tissue) to life-threatening complications quiescent until late adulthood (urachal carcinoma). This section will review the 'state of the art' in evaluation and management of these umbilical and related abnormalities.

Impact of umbilical cord cleansing with 4.0% chlorhexidine on time to cord separation among newborns in southern Nepal: a cluster-randomized, community-based trial

OBJECTIVE

Within a community-based, cluster-randomized study of the effects of 4.0% chlorhexidine on omphalitis and mortality risk, we aimed to describe the distribution of times to separation and the impact of topical chlorhexidine treatment on cord-separation times.

METHODS

Between November 2002 and March 2005, 15123 infants were assigned randomly within communities in southern Nepal to receive 1 of the following 3 cord-care regimens: cleansing with 4.0% chlorhexidine, cleansing with soap and water, or dry cord care. In intervention clusters, field workers cleansed the cord in the home on days 1, 2, 3, 4, 6, 8, and 10 after birth. Newborns were monitored throughout the newborn period for signs of omphalitis, and the time to cord separation was noted. Separation times were compared across treatment groups. Cord infection risk and a range of infant and household characteristics were assessed for their relationships to separation time.

RESULTS

The mean separation time was shorter in dry cord care (4.24 days) and soap/water (4.25 days) clusters than in chlorhexidine clusters (5.32 days; mean difference: 1.08 days). Cords of infants who received chlorhexidine were 3.6 times more likely to separate after 7 days. Separation time was not associated with omphalitis. Home-delivered topical antiseptics, facility-based birth, and birth attendant hand-washing were associated with greater likelihoods of cord separation after 7 days of age.

CONCLUSIONS

In this setting, the umbilical cord separated more rapidly than observed in hospital-based studies, and the impact of chlorhexidine cleansing on separation times was negligible. Increased cord-separation time attributable to topical chlorhexidine treatment should not be considered a factor in decision-making in settings where the baseline risk of omphalitis is high and chlorhexidine might reduce infection and mortality risks significantly.

Umbilical cord care: a pilot study comparing topical human milk, povidone-iodine, and dry care

OBJECTIVE

To compare the incidence of omphalitis among three groups, each using a different type of newborn cord care: povidone-iodine, dry care, and topical human milk.

DESIGN

Case control.

SETTING

A large urban university hospital in Turkey and participant homes after discharge.

PARTICIPANTS

150 healthy, full-term newborns and their mothers.

INTERVENTIONS

Umbilical cord care consisted of one of three methods: topical application of povidone-iodine twice daily, topical application of mother's milk twice daily, or dry care (keeping the cord dry and clean).

MAIN OUTCOME MEASURE

Outcome was measured in terms of the presence or absence of omphalitis and the number of days elapsed before cord separation. An ongoing questionnaire was administered by telephone every other day after the participants left the hospital. In addition to demographic information, the cord separation day and any signs of omphalitis were recorded in the questionnaire.

RESULTS

There were no significant differences between the three groups in terms of omphalitis occurrence. Two cases of omphalitis were observed (one in the human milk group, one in the povidone-iodine group). Interestingly, babies in the dry care or topical human milk group had shorter cord separation times than those in the povidone-iodine group.

CONCLUSION

The cultural practice of applying human milk to the umbilical cord stump appears to have no adverse effects and is associated with shorter cord separation times than are seen with the use of antiseptics.

Clinical significance of the umbilical cord twist

OBJECTIVE

The objective of this study was to determine the clinical significance of the umbilical cord twist direction.

STUDY DESIGN

Two hundred singleton third-trimester placentas with a right umbilical cord twist and 200 placentas with a left umbilical cord twist, which was determined by pathologic examination, were included. Maternal and neonatal outcomes were compared with the use of Fisher's exact and Mann Whitney U tests; a probability value of <.05 considered statistically significant.

RESULTS

Placenta previa was more common in patients with a right umbilical cord twist compared with a left umbilical cord twist (6.0% vs 1.5%; P<.05). There was a trend towards an increased incidence of single umbilical artery in patients with a right umbilical cord twist (2.5% vs 0%; P=.06). The incidence of fetal demise, intrauterine growth restriction, chromosomal abnormalities, congenital anomalies, preterm delivery, infant gender, birth weight, maternal age, and parity were similar between the 2 groups.

CONCLUSION

Placenta previa is associated with a right umbilical cord twist.

Umbilical cord length and parity--the Greek experience

OBJECTIVES

To investigate the relationship between parity and cord length, with respect to peripartum characteristics.

STUDY DESIGN

Parity, cord length, placental and birth weight were the studied variables in a sample of 534 parturients with singleton fetuses. Parturients were divided into four groups: primiparous (para-1), secundiparous (para-2), tetriparous (para-3) and multiparous (para >3). Oneway ANOVA and post-hoc tests were applied for the comparison of mean cord length between the four groups of parity. General Linear Model was applied for the detection of covariates.

RESULTS

ANOVA yielded significant differences between the four groups. Mean cord length was significantly higher in women of parity >or=3 than in women with lower parity. Although both placental and birth weight were correlated with cord length, application of GLM showed that only birth weight could act as a covariate for the length differences between parity groups.

CONCLUSIONS

Cord length appears to increase with advancing parity, the cut-off point being between the second and the third labor. We suggest that intrapartum monitoring should be performed in all multiparous parturients, because of their propensity for longer cords, and thus for related complications.