Further studies on the umbilical cord and its water content.

Abstract

SUMMARY The results show that the varied appearance of the umbilical cord at birth can be related to its water content and that there are associated changes to be seen histologically in all layers of the cord, but especially in Wharton's jelly. Quantimet analysis confirms these findings and highlights a small group where dual pathology may exist. The relationship between oedematous cords, large drip volume, and respiratory distress in the newborn is considered, and a possible explanation for reduced placental transfusion and low red cell mass in these babies is proffered.At birth the umbilical cord varies quite considerably in appearance and the changes may have a bearing on the progress of the infant. For example, oedema can be a warning of pending respiratory distress or transient respiratory distress, depending on maturity (Coulter et al., 1975), and a thin, wrinkled cord is frequently associated with a light-for-dates or postmature infant (Scott and Jordan, 1972). Wharton's jelly, which surrounds the vessels of the cord, has the properties of a thyxotropic gell (Bacsich and Riddell, 1945) and is capable of holding large amounts of water. It seemed reasonable that much of the change noted above might be related to altered water content. Therefore freeze-drying experiments were designed to investigate this hypothesis. The findings were compared with histological appearance and Quantimet analysis. Since it had been noted that placentae showing cord oedema tended to drip larger amounts of bloodstained fluid over the 24 hours after delivery this fluid was taken for analysis. MethodsFour lines of investigation were instituted: 1 Umbilical cords from 57 cases were examined, measured, and graded as before (Scott and Jordan, 1972;Coulter et al., 1975). Diameters were measured at right-angles in the same plane, in segments where vessels wer%. empty, and the maximum value of the product obtained was regarded as the reading for that cord. Twenty-four were oedematous with diameter-products (DP) of 1-3 or more, and 16 were Received for publication 28 February 1978 thin and wrinkled with DP less than 0-6. The remaining 17 were normal with DP values in the intermediate range. Sections 3-4 mm thick were taken from all the measurement sites. These were blotted to remove excess blood, and the percentage water content was estimated using an Edwards Speedivac centrifugal freeze dryer. Test runs showed that a constant weight could be obtained after 24 hours. 2 Placentae from these cords and a further control series of 430 cases, which ranged from 31 to 42 weeks' gestation, having approximately 50 cases in each group, were examined and scored (Scott and

Umbilical Cord Mercury Concentration as Biomarker of Prenatal Exposure to Methylmercury

“…The appearance of the umbilical cord varies substantially and is mainly due to differences in water content retained by the gelatinous Wharton’s jelly that surrounds the blood vessels (Scott and Wilkinson 1978; Sloper et al 1979). The mean water content decreases with increasing duration of gestation, and the fetal end of the cord has a higher water content than does the placental end (Sloper et al 1979).…”

“…Vessel contractions within the first couple of minutes after birth (Yao and Lind 1974) will determine the blood content of the cord sample. Umbilical cords differ in thickness and overall appearance, largely due to varying amounts of Wharton’s jelly (Scott and Wilkinson 1978), the amount of which decreases with the duration of gestation (Sloper et al 1979). The cord mercury concentration is therefore usually expressed in terms of dry weight (Akagi et al 1998; Dalgård et al 1994).…”

Anatomy and Pathology of the Umbilical Cord and Major Fetal Vessels

“…The water content of the umbilical cord has been studied in great detail by Scott and Wilkinson (1978). Edematous cords had a water content of 93.5%, and wrinkled cords had 89.2% water.…”

Absence of Wharton’s jelly around the umbilical arteries

“…It was suggested that amount of Wharton's jelly or its water content goes on decreasing with advancing gestation. 6 A condition differing from that described here is 'insertion funiculi furcata' in which the site of cord insertion is normal but, prior to insertion, the vessels lose their protective covering of Wharton's jelly. 1 In this entity, the vessels branch before reaching the placental surface.…”