Abstract
Glycosylated haemoglobin (HbA1) was measured in 164 Caucasian women aged 20–40 years who were using: (1) barrier contraceptive methods; (2) contraceptive pills with 30 μg ethinyloestradiol and 150 μg laevo-norgestrel; (3) contraceptive pills with 30–35 μg ethinyloestradiol and 0.5–1 mg norethisterone. Mean ± 1 s.d. values for the three groups were 7.64 ± 0.69, 7.56 ± 0.56 and 7.27 ± 0.74 respectively. Groups (1) and (2) did not differ significantly from one another but the mean value for group (3) was significantly lower than for the other groups (P < 0.01). Age, percentage ideal body weight and smoking did not influence HbA1 but the value was higher for parous than for nulliparous women (P = 0.02). These findings can be explained in terms of the known effects of oestrogens and progestogens on fasting blood glucose.