This investigation is a follow‐up of a previous study in which intravenous glucose tolerance tests (IVGTT) had been performed in women with complicated pregnancies. The series included 129 women with infants weighing 4.5 kg or more (LB) and a control group of 82 women with normal pregnancies and infants of normal weight (series I). In the present follow‐up (series II), 82 of the women with LB and 52 of the control women could be retested. The time lapse between the testings was 5–7 years. In the control series, there was a significant mean decrease in K‐values (K being the disappearance rate constant for intravenously injected glucose) from 2.22 ± 0.71 to 1.65 ±0.59 S.D. In the group of women with LB the mean K‐value decreased from 2.09 ± 0.77 to 1.35 ± 0.51 S.D. (p< 0.001). In the control group there were 7% and in the group of women with LB there were 24% who had K‐values below the normal lower limit of 1.0. In series I the corresponding figures were 0% and 10%. 18% of the women with LB were overweight themselves and had a significantly lower It‐value than the women with LB who were themselves of normal weight. The frequency of diabetes mellitus among first degree relatives of the mothers with LB was 28% and of the controls 2%. Between the two tests a further 2 women in this group had developed manifest diabetes compared to none in the control group.