A high percentage of women receiving 5 mg. of norethynodrel with mestranol in cyclic fashion for contraception have decreased glucose tolerance. Ten per cent have elevated fasting levels, 20 per cent have elevated one-hour levels and 46 per cent have elevated two-hour levels (greater than our normal mean + 2 standard deviations of 105, 156 and 113 mg./100 ml., respectively). The incidence of abnormal glucose tolerance is greater in women with a family history of diabetes than in those without a history.
It seems reasonable to associate the change in glucose tolerance with the [pseudo-pregnancy] produced by the drug. Many women who have decreased glucose tolerance during natural pregnancy later become permanently diabetic. If this is true of those women with decreased glucose during drug treatment, then this response may identify the prediabetic.