Steroids in newborns and infants. The changing pattern of urinary steroid excretion during infancy

Urinary steroids from infants 1 to 9 mth of age have been analysed by gas chromatography and combined gas chromatography mass spectrometry. Open tubular capillary columns were used for the gas chromatographic analyses. These greatly improved the resolution of steroid methyloxime trimethylsilyl ethers over that obtained with packed columns. The major 3β hydroxy Δ⁵ steroids found in the younger infants were 3β,16α dihydroxy 5 androsten 17 one, 3β,17β dihydroxy 5 androsten 16 one, 5 androstene 3β,16α,17β triol and 3β,16α dihydroxy 5 pregnen 20 one. In the older infants 5 pregnene 3β,20α diol and 5 pregnene 3β,20β comparison of the were the predominant 3β hydroxy Δ⁵ steroids. However, there was a general decrease in the amount of 3β hydroxy Δ⁵ steroids excreted relative to the total steroid excretion. Cortisol metabolites were found in urine from infants of all ages. The principal metabolite was tetrahydrocortisone the excretion of which varied between 100 and 700 μg/24 h. 5β pregnane 3a, 17a, 20a triol (pregnane triol) was assayed in each urine sample but only became quantitatively significant after the fourth mth of life ( 20 - 120 μg/24 hr in the later samples).