Free Loop Of Umbilical Cord Research Articles

Ultrasound Assessment of Umbilical Cord Morphology in the First Trimester: A Feasibility Study

Objective: The aim of this study was to determine whether morphology and measurement of the umbilical cord could be accurately assessed at the time of the 11- to 13⁺⁶-week scan. Methods: We conducted a prospective study of 100 consecutive women with singleton pregnancies at 11-13⁺⁶ weeks' gestation who were seen for routine aneuploidy screening. Transabdominal ultrasound scans were performed, and the distance between two adjacent coils of the umbilical artery was measured in a free loop of umbilical cord. The antenatal umbilical coiling index (aUCI) was calculated as the inverse of this measurement (aUCI = 1/intercoil distance in cm). The maximum diameter of the umbilical vein was measured. Umbilical venous blood flow velocity was obtained using standard Doppler technique. Interobserver variability was assessed. A subjective assessment of the cord was performed using the Sepulveda system of classification to compare the reproducibility of the observations between two observers. Results: The intended measurements could be obtained in all cases. The aUCI was found to decrease with advancing gestation, while the umbilical venous diameter increased with gestation. The umbilical venous blood flow velocity also increased with gestation. Interobserver consistency in the objective measurement of the aUCI was poor (kappa 0.146). However, the Sepulveda classification system was found to be applicable and reproducible at this period of gestation (kappa 0.601). Conclusions: Umbilical cord morphology can be consistently studied in the first trimester. A subjective method of evaluation of the morphology may be a more reproducible technique until measurement strategies are refined and operator experience developed.

155: Assessment of the number of umbilical cord vessels at the time of nuchal translucency screening

Objective: To investigate feasibility of identifying the number of vessels in umbilical cord during nuchal translucency screening. Methods: We performed a prospective study in patients undergoing nuchal translucency screening at 11.0-13.9 weeks’ from 2011-2012. An oblique transverse view of fetal abdomen utilizing Doppler flow and a cross section view of free loop of umbilical cord were obtained. Maternal characteristics, technical aspects of first trimester ultrasound, and number of umbilical cord vessels identified in the second trimester were collected. McNemar’s test and kappa analysis were used to compare quantification of umbilical cord vessels in the first vs. second trimesters. Results: Total of 123 women were included. The number of umbilical cord vessels was successfully visualized in 95.9% of patients utilizing the bladder view, and 65.0% of patients on cross sectional cord views. Three-vessel cord was correctly identified in 99.2% of patients; one case was incorrectly diagnosed with a two two-vessel cord. McNemar’s test indicated that overall, first and second trimester ultrasounds have the same propensity to detect umbilical cord vessels (p=0.414), with moderate agreement (kappa=0.226). Conclusions: Identification of umbilical cord vasculature is possible in the first trimester and can be used as an adjunct to early fetal anatomy evaluation.

P05.04: Ultrasound assessment of umbilical cord morphology in the first trimester: a feasibility study

Objective: The aim of this study was to determine whether morphology and measurement of the umbilical cord could be accurately assessed at the time of the 11- to 13 +6 -week scan. Methods: We conducted a prospective study of 100 consecutive women with singleton pregnancies at 11–13 +6 weeks’ gestation who were seen for routine aneuploidy screening. Transabdominal ultrasound scans were performed, and the distance between two adjacent coils of the umbilical artery was measured in a free loop of umbilical cord. The antenatal umbilical coiling index (aUCI) was calculated as the inverse of this measurement (aUCI = 1/intercoil distance in cm). The maximum diameter of the umbilical vein was measured. Umbilical venous blood flow velocity was obtained using standard Doppler technique. Interobserver variability was assessed. A subjective assessment of the cord was performed using the Sepulveda system of classification to compare the reproducibility of the observations between two observers. Results: The intended measurements could be obtained in all cases. The aUCI was found to decrease with advancing gestation, while the umbilical venous diameter increased with gestation. The umbilical venous blood flow

Evaluation of umbilical cord thickness, cross-sectional area, and coiling index as predictors of pregnancy outcome

Aims:This study was designed to evaluate the relationship of sonographic measurements of umbilical cord thickness, cross-sectional area, and coiling index with pregnancy outcome (low birth weight, 5-min Apgar score, and meconium staining).Materials and Methods:From January 2010 to January 2011, among 255 singleton pregnant women who were referred for routine pregnancy USG after 20 weeks of gestation, 223 fulfilled the study criteria. In these patients, the diameter, cross-sectional area, and coiling index were measured in a free loop of umbilical cord. The pregnancies were followed till delivery, when birth weight, presence of meconium staining, and 5-min Apgar score were recorded. The sonographic measurements and clinical findings were analyzed to determine any correlation.Results:A statistically significant correlation was observed between small umbilical cord thickness and cross-sectional area and low birth weight (LBW), with sensitivity of 52.9% and 57.9%, specificity of 95.0% and 94.4%, positive predictive value of 52.6% and 52.0%, and negative predictive value of 95.0% and 95.0%, respectively. Also noted was significant correlation between small umbilical cord thickness and cross-sectional area with meconium staining (P<0.001). No significant correlation was seen between umbilical cord thickness and cross-sectional area with low 5-min Apgar score. There was no statistically significant correlation between umbilical cord coiling index and LBW, 5-min Apgar score, and meconium staining.Conclusion:Umbilical cord diameter and cross-sectional area measured after 20 weeks of gestation are useful for predicting LBW and meconium staining and have the potential to serve as markers for adverse pregnancy outcome.

Reference ranges for serial measurements of umbilical artery Doppler indices in the second half of pregnancy

The purpose of this study was to construct new reference ranges for serial measurements of commonly used umbilical artery Doppler indices (pulsatility index, resistance index, and systolic:diastolic ratio). This was a prospective longitudinal study of the umbilical artery Doppler indices that were obtained serially at the free-loop of umbilical cord at 4-week intervals at 19 to 42 weeks of gestation in 130 low-risk singleton pregnancies. A total of 513 observations were used to construct the reference ranges with the use of multilevel modeling. Longitudinally established percentiles of Doppler indices from the present study show a continuous reduction throughout the second half of pregnancy without any plateau or increase near term, as reported previously. There was a significant negative association between Doppler indices and placental weight and neonatal birth weight, but not with gender. The intraobserver coefficients of variation for the umbilical artery pulsatility index, resistance index, and systolic:diastolic ratio were 10.5%, 6.8 %, and 13.0 %, respectively. New reference ranges for umbilical artery Doppler indices that are based on longitudinal observations appear to be slightly different from cross-sectional studies and are more appropriate for serial evaluation of fetal hemodynamics.

P60Effectiveness of treatment the fetal hemolytic disease by intravascular transfusions

BackgroundThe aim of our study was to estimate the efficacy of treatment the fetal hemolytic disease by intravascular transfusions (IVT).MethodIn the group of 71 immunized patients, after 21 weeks' gestation we performed amniocentesis. Results of the optical density at 450 nm in 2nd or 3rd zone in Liley's scale were an indication for cordocentesis, fetal blood sampling and in cases with low values of blood parameters – intravascular transfusion with drugs administration. In some cases we chose elective preterm cesarean delivery. The management depended on the gestational age, fetal maturity, blood parameters, ultrasound examination and FHR patterns.ResultsThe number of 24/71 patients required IVT. We transfused 20–90 ml of blood in 3–10 days intervals. The total amount of IVT was 78: 65/78 into a free loop of umbilical cord and 13/78 into its placental insertion. In 22/24 cases there were born healthy neonates, five of them required exchange transfusion because of hyperbilirubinemia. We observed one intrauterine death 10 h after IVT, probably due to cord hematoma and one death of hydropic neonate 48 h after delivery.ConclusionThe treatment of fetal hemolytic disease by IVT is associated with high perinatal survival rate and low perinatal mortality rate.

Sonographic Evaluation of the Two Vessel Umbilical Cord

Evaluation of the umbilical cord is an important part of a fetal ultrasound examination. The gold standard for documenting the umbilical cord has been an axial section of a free loop of umbilical cord within the amniotic fluid. There are normally two umbilical arteries and one umbilical vein, but in approximately 1% of pregnancies, only one umbilical artery is present. The presence of a two vessel umbilical cord or a single umbilical artery has been associated with an increase in other fetal abnormalities. When axial views of the umbilical cord are not obtainable, it is common practice to use color Doppler to determine the presence or absence of the umbilical arteries as they course adjacent to the fetal bladder. The three-vessel cord is confirmed by identifying the right and left umbilical arteries on each side of the bladder. This study compared axial views of free-floating two vessel umbilical cords with color Doppler evaluation of the umbilical arteries adjacent to the bladder and attempted to answer three questions regarding the single umbilical artery: 1) Does the presence of two umbilical arteries next to the fetal urinary bladder validate the documentation of a three vessel umbilical cord; 2) When one umbilical artery was absent, was there a prevalence as to which side was affected; and 3) Does the side of the absent umbilical artery correlate with an increase or decrease in risk for other anomalies? This study showed that there were three sonographic variations with respect to a two vessel umbilical cord when axial gray scale images of the umbilical cord were compared with color Doppler images of the umbilical arteries adjacent to the fetal urinary bladder. The most prevalent variation, occurring in 17 (49%) of 35 cases, was the two-vessel cord with the left umbilical artery absent. The right umbilical artery was absent in 13 (37%) of 35 cases. The third and least prevalent variation, occurring in five (14%) of 35 cases, was a two vessel umbilical cord with both umbilical arteries present adjacent to the fetal urinary bladder. Each of the single umbilical artery variations in the study were associated equally with other sonographically identifiable abnormalities. We conclude that a two vessel umbilical cord may be missed by relying solely on color Doppler views of the umbilical arteries adjacent to the bladder.