In mid 1980s most diabetes in pregnancy was in women with type 1 diabetes, with long periods of time spent as inpatients. Gestational diabetes (GDM) was diagnosed on the 3hour 100g glucose load GTT. An increased rate of congenital malformations was noted in women with GDM and the high risk ethnicity was mainly Mediterranean. Glucose meters were expensive and had limited availability. Co-located multidisciplinary diabetes antenatal clinics were running and ‘busy’ with ~14 women per week.
From 1991 universal screening started using the 2-step process and ADIPS criteria, though higher risk women were tested in early 2nd trimester and a 1-hour glucose was also used in GDM diagnosis. Around that time the ethnicity of the local population was changing with a marked increase in the number of women of Asian ethnicity, predominantly Chinese, being seen.
From the beginning of 2015 the IADPSG/WHO criteria were used for diagnosis of GDM increasing the GDM prevalence from ~15% to 18% and with another change of ethnic mix with a decrease in the number of Chinese women but increase in those of South Asian ethnicity being seen. In addition over time there has been a significant rise in maternal age and pre-pregnancy weight/BMI. Antenatal clinics now average 100+ women per week in addition to those having initial visits or starting insulin, attending other antenatal clinics eg twins, and non-face-to-face diabetes stabilisation services offered.
There has been a longstanding interest in the heterogeneity of gestational diabetes and need for individualisation of care.
Since the early 1990s there has been also an increase in the number of women with pre-gestational diabetes, particularly those with type 2 diabetes. Although there has been an improvement in the number of women with type 1 having diabetes-specific pre-pregnancy planning (~75% compared to ~40%), the rate of pre-pregnancy planning in women with type 2 diabetes has remained poor at about 20%.