Use of small samples of urine to monitor gonadotrophins in menopausal women.

The increased gonadotrophin secretion which occurs at the menopause was followed by measuring gonadotrophin to creatinine ratios in small samples of urine. For follicle stimulating hormone, values of the ratio corresponded closely with both plasma concentration (correlation coefficients: 0.93, 0.94 and 0.93 for first morning, mid-morning and mid-afternoon urine samples: all results expressed as logarithms) and 24-h urine output (0.98, 0.96 and 0.94). Comparable figures for luteinising hormone (LH) were 0.94, 0.94 and 0.90; and 0.95, 0.95 and 0.90. Multiplication of the gonadotrophin to creatinine ratios (I.U./mmol) by 10 gave a figure close to 24-h gonadotrophin output (I.U.).