Thank you for your comments on our paper. We only collected ‘peak HbA1c’, the highest HbA1c measured in the pregnancy in that patient, for the women in the study. The ‘affected’ pregnancies had higher peak HbA1c in both type I and type II diabetes (8.0 versus 8.9, P= 0.0035). Although peak HbA1c might not be an internationally recognised measure of control, this result does suggest poorer control in affected pregnancies. Why Pakistani women have a worse outcome is likely to be multifactorial and include socio-economic factors, but our data does not allow us to separate out these factors. In contrast with the nonwhite population in Clausen's study, which was diverse, Bradford's nonwhite women with diabetes were mainly Pakistani. We were therefore able to correct for this variable and found that the poor outcome appeared to be a consequence of ethnicity rather than diabetes type. It is likely that deprivation is also a factor, as generally deprivation is more common in the Pakistani population, but in the absence of specific data, we cannot test this assumption.
The take up of pre-pregnancy counselling in our Pakistani women is low, so our assumption is that the women with type II diabetes, who were on insulin before pregnancy, had poor control with diet/oral medication. Diabetic control should improve with insulin. It came to us as a surprise to find that the use of insulin was related to a poorer outcome, but possibly this use before pregnancy has prevented even worse outcomes.
Alternatively, insulin maybe teratogenic: perinatal mortality was only slightly increased, but the congenital abnormality rate was ten-fold higher in the insulin group! The numbers in our study group were too small to draw any conclusions on the cause of these differences.