Cord entanglement in monochorionic monoamniotic twins.

Monochorionic monoamniotic twin gestations have been associated with perinatal mortality rates as high as 28% to 47%. Umbilical cord entanglements and knots, twin-to-twin transfusion syndrome, congenital anomalies, prematurity and intertwin locking during labor are responsible for their high perinatal morbidity and mortality. We report here two cases of cord entanglements: One of them was associated with twin-to-twin transfusion syndrome with gross vascular anastomoses and a massive cord entanglement. The other one was associated with cesarean section due to dystocia of cord entanglement of the second fetus after vaginal birth of the first one. There is still no consensus in literature for the management and the mode of delivery of these rarely encountered cases (Fig. 3, Ref. 13).

Standardization of diagnosis for coiling of the umbilical cord around fetal neck by ultrasound.

OBJECTIVE: To elucidate classification of coiling of the umbilical cord around fetal neck (CUFN) by ultrasound and forming factors of entanglement angle of CUFN. METHODS: From January 2006 to December 2012, color Doppler ultrasonic was used to observe the blood flow vector of umbilical artery, and prospective descriptive observation was made for entanglement direction and type of 707 single fetuses taking prenatal examination in our hospital during the middle and late trimester of pregnancy and having umbilical cord echo around the neck. The relationship of position of fetus, position of placenta and entanglement direction of umbilical cord with the entanglement angle of umbilical cord is analyzed. RESULTS: Among the 707 fetuses, 634 had one circle of coiling, 43 had two circles of coiling, two had three circles of coiling, and 28 had CUFN. According to entanglement direction, 361 had entanglement from left to right and 318 had entanglement from right to left According to entanglement type, 305 were C-shaped type (43.14%), 85 were O-shaped type (12.02%), 289 were α-shaped type (40.88%), and 28 were L-shaped type (3.96%). CONCLUSION: Color Doppler ultrasound was used to detect the entanglement direction of umbilical cord and establish the five-type classification of umbilical cord around the neck, laying the foundation for the feasibility of establishing the normalization of diagnostic standard of umbilical cord around the neck.

Investigation of possible maternal and fetal factors which affect umbilical coiling index.

AIM: The aim of this study was to investigate the possible maternal and fetal factors, which affect the Umbilical Coiling Index (UCI). METHODS: This prospective, observational, analytic study was conducted using the data of 380 women with term pregnancy and newborns who presented at a University Hospital. Hemoglobin (Hb), ferritin, iron, and the total iron binding capacity (TIBC) of the maternal blood were measured, and transferrin saturation was estimated based on the ratio between serum iron and TIBC. Blood gases, ferritin, iron, and TIBC of the umbilical cord were also measured, and the transferrin saturation was calculated. The length and thickness of the umbilical cord, numbers of coilings, weight of placenta, neonatal weight were registered. The UCI was calculated dividing the total number of coils by the length of the umbilical cord (in cm). RESULTS: A positive, linear, and statistically significant relationship was found between the UCI scores and the umbilical cord blood transferrin saturation, umbilical cord thickness, and the first- and fifth-min APGAR scores (p = .044, p < .001, p = .008, p = .022, respectively). No statistically significant relationship was found between the maternal Hb values and the UCI scores (p = .472). In addition, there was no statistically significant relationship between the UCI scores and maternal ferritin, maternal transferrin saturation and umbilical cordon ferritin levels (p = .940, p = .681, and p = .975, respectively). CONCLUSIONS: A positive correlation was found between the UCI and umbilical cord transferrin saturation and between the newborn APGAR scores. However, this finding is not sufficient to explain the relationship of the umbilical cord dynamics with the newborn wellbeing and coiling.

Cardiac defects, nuchal edema and abnormal lymphatic development are not associated with morphological changes in the ductus venosus.

BACKGROUND: In human fetuses with cardiac defects and increased nuchal translucency, abnormal ductus venosus flow velocity waveforms are observed. It is unknown whether abnormal ductus venosus flow velocity waveforms in fetuses with increased nuchal translucency are a reflection of altered cardiac function or are caused by local morphological alterations in the ductus venosus. AIM: The aim of this study was to investigate if the observed increased nuchal translucency, cardiac defects and abnormal lymphatic development in the examined mouse models are associated with local changes in ductus venosus morphology. STUDY DESIGN: Mouse embryos with anomalous lymphatic development and nuchal edema (Ccbe1(-/-) embryos), mouse embryos with cardiac defects and nuchal edema (Fkbp12(-/-), Tbx1(-/-), Chd7(fl/fl);Mesp1Cre, Jarid2(-/-NE+) embryos) and mouse embryos with cardiac defects without nuchal edema (Tbx2(-/-), Fgf10(-/-), Jarid2(-/-NE-) embryos) were examined. Embryos were analyzed from embryonic day (E) 11.5 to 15.5 using markers for endothelium, smooth muscle actin, nerve tissue and elastic fibers. RESULTS: All mutant and wild-type mouse embryos showed similar, positive endothelial and smooth muscle cell expression in the ductus venosus at E11.5-15.5. Nerve marker and elastic fiber expression were not identified in the ductus venosus in all investigated mutant and wild-type embryos. Local morphology and expression of the used markers were similar in the ductus venosus in all examined mutant and wild-type embryos. CONCLUSIONS: Cardiac defects, nuchal edema and abnormal lymphatic development are not associated with morphological changes in the ductus venosus. Ductus venosus flow velocity waveforms most probably reflect intracardiac pressure.

Notching of the umbilical artery waveform associated with cord entanglement in a monoamniotic twin pregnancy.

Cord accidents are the principal cause of the high rates of morbidity and mortality associated with monoamniotic twins. Observation of an umbilical artery notch might be a highly specific sign for cord entanglement involving a tight cord knot. It thus justifies the implementation of intense surveillance and should be one of the factors taken into account in deciding on early delivery of the twins.