INS and type 1 diabetes mellitus: However, this optimal glycaemic control is difficult to accomplish given the complexity of insulin dose adjustment, gestational changes in insulin sensitivity and marked day-to-day variability in insulin absorption during late pregnancy.11, 12, 13 Nationwide UK data confirm that only 15% of pregnant women achieve target glycated haemoglobin (HbA1c) levels during early pregnancy and that despite intensive support (2-weekly antenatal clinics and frequent between-clinic contacts), only 40% of women with type 1 diabetes achieve target HbA1c levels after 24 weeks' gestation.9