Oedema of the umbilical cord and respiratory distress in the newborn.

Oedema of the umbilical cord, defined as visible oedema in a cord wish a minimal cross sectional area of 1-3 cm-2, is found in 10 per cent of deliverieo. It is seen more frequently in cetain complications of pregnancy such as abrupti placentage, maternal diabetes, macerated intrauterine death and in conditions affectint the infant including prematurity, rhesus isoimmunization, respiratory distress syndrome (RDS) and transient respiratory distress (TRD). There is a higher incidence in infants delivered by Caesarean section. There is no significant association between cord oedema and either fetal distress or neonatal asphyxia nor is there any correlation with maternal hypertension or oedema. The mechanism of production of the odema is discussed; low oncotic pressure, raised hydrostatic pressure in the placenta and umbilical cord, and an increase in total water in the feto-placental unit are considered. The presence of oedema of the cord may reflect similar changes in the lungs which antenatally predispose aninfant whose pathway for production of surfactant is immature to develop RDS and the mature infant to develop TRD. The value of cord oedema as a warning sign is stressed.