During the neonatal period infants of diabetic mothers often have attacks of cyanosis, temporary cardiac murmurs and arrhythmia. Electrocardiographic changes have been observed both in the presence and in the absence of such disturbances, but in none of the children with any of these disturbances was the electrocardiogram normal (Björklund, 1953 b). The hypothesis has been advanced that the clinical symptoms and electrocardiographic changes are caused by hypokalaemia, secondary to hyperinsulinism with concomitant hyperfunction or dysfunction of the adrenal cortex (Björklund, 1953 a, b).
Venning et al. (1949) found in 2 premature infants of diabetic mothers, delivered by Caesarean section, increased glucocorticoid excretion during the first few days of life. Normalization of the excretion occurred on about the fifth day. Since these 2 infants had atelectasis and cyanosis, Venning et al. considered that the stress to which these babies were exposed was the cause of the increased function of the