[Creatine kinase and creatine kinase isoenzymes in the serum of newborn infants. 1. Effect of the mode of delivery on total CK and CK-B].

The total CK-, CK-B- and CK-M-activity was determined in 48 newborns from the first to the third day of life by use of the "CK-Monotest" (Boehringer Mannheim). Opposite to a very small decrease of the total CK-activity a significant decrease of the CK-B is evident in the same time. At the first day the detection of CK-B was impossible in only 1 of 27 patients, but at the third day a low CK-B level was detectable in only 5 of 11 test persons. The activities of total CK and the CK-B were determined based upon these investigations in 245 newborns at the first day of life by use of the "CK-Monotest NAC activated" (Boehringer Mannheim). There was no significant difference of total CK- and CK-B-activity dependent on the mode of delivery (spontaneous vertex presentation, forceps delivery, caesarean section, breech presentation.) The proportion of the CK-B varied between 8 and 11% of the total creatine kinase in dependence on the mode of delivery.