Plasma pancreatic glucagon and insulin: glucagon ratio at birth.

of delivery (14) the mean (±SE) plasma concentration of glucose was 99±7 mg/100 ml, insulin 32±6 ,uU/ml, glucagon 183±17 pg/ml. These levels were similar to those occurring in mothers who did not have an i.v. infusion, permitting pooling of the two groups for further analysis. The 't' test for paired data was used for statistical comparison of plasma concentrations of metabolite or hormones. The mean (±SE) difference between maternal and umbilical venous plasma glucose was 22 ±3 mg/100 ml, and between umbilical vein and artery 8 ±1 mg/100 ml. The mean (±SE) maternal venous plasma insulin level was 10 ±3 [U/ml higher than that in the umbilical vein. There was no significant difference between any pair of samples in plasma glucagon levels. Analyses of linear correlation were performed between plasma glucose and plasma insulin, glucagon and the insulin: glucagon ratio. Maternal plasma glucose and insulin levels were significantly correlated (r = 0 411 P < 0 05) as were umbilical venous plasma glucose and insulin levels (r = 0-512 P < 0 01). Plasma glucagon levels were not significantly correlated with insulin or glucose levels in any of the three blood samples. The insulin: glucagon ratio correlated significantly with plasma glucose concentration in maternal venous blood (r = 0 447 P < 0 01), umbilical venous blood (r = 0 473 P < 0 01), and umbilical arterial blood (r 0 389 P < 0 05).