Colloid osmotic pressure of cord blood in relation to neonatal outcome and mode of delivery.

Colloid osmotic pressure (COP) of umbilical cord blood was measured in 184 infants, 113 of whom were delivered vaginally and 71 by Caesarean section, 152 were born at term and 32 were preterm (gestational age less than 37 weeks). Thirteen infants developed RDS, 20 had transient tachypnoea (TT) and 13 had perinatal asphyxia. There was a significant linear correlation between COP and total protein in cord blood (r = 0.91). Such a correlation was also found between COP of cord blood and gestational age in the non-RDS group (r = 0.49). COP was higher (19.6 mmHg) in the infants delivered vaginally than in those delivered by Caesarean section (16.8 mmHg, p less than 0.001). In the RDS group COP was 13.2 mmHg, in the TT group 15.6 mmHg and in the asphyctic group 16.9 mmHg (normal 18.3 mmHg). COP appeared to be of diagnostic assistance in babies developing neonatal pulmonary maladaptation syndromes.