Trends in Factors Affecting Pregnancy Outcomes Among Women With Type 1 or Type 2 Diabetes of Childbearing Age (2004-2017)

Aim: To describe trends in modifiable and non-modifiable unfavorable factors affecting pregnancy outcomes, over time (years 2004-2017), in women with diabetes of childbearing age from an English primary care perspective.

Methods: We identified women with diabetes aged 16-45 years from the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) network, an English primary care sentinel database. Repeated annual cross-sectional analyses (2004-2017) assessed the prevalence of unfavorable factors for pregnancy, such as obesity, poor glycaemic control, microalbuminuria, hypertension, use of medications for treating diabetes, and associated comorbidities not recommended for pregnancy.

Results: We identified 3,218 women (61.5% with Type 2 diabetes) in 2004 and 6,657 (65.0% with Type 2 diabetes) in 2017. The proportion of women with ideal glycaemic control for conception (HbA1c<6.5%) increased over time, in patients with Type 1 diabetes from 9.0% (7.1%-11.0%) to 19.1% (17.2%-21.1%), and in those with Type 2 diabetes from 27.2% (24.6%-29.9%) to 35.4% (33.6%-37.1%). The proportion of women with Type 2 diabetes prescribed medications different from insulin and metformin rose from 22.3% (20.5%-24.2%) to 27.3% (26.0%-28.6%).In 2017, 14.0% (12.6%-15.4%) of women with Type 1 and 30.7% (29.3%-32.0%) with Type 2 diabetes were prescribed angiotensin-modulating antihypertensives or statins. We captured at least one unfavorable factor for pregnancy in 50.9% (48.8%-52.9%) of women with Type 1 diabetes and 70.7% (69.3%-72.0%) of women with Type 2 diabetes. Only one third of women with Type 1 diabetes (32.2%, 30.3%-34.0%) and a quarter of those with Type 2 diabetes (23.1%, 21.9%-24.4%) were prescribed hormonal contraception. Contraception was prescribed more frequently to women with unfavorable factors for pregnancy compared to those without, however, the difference was significant only for women with Type 1 diabetes.

Conclusions: Despite significant improvements in general diabetes care, the majority of women with Type 1 or Type 2 diabetes have unfavorable, although mostly modifiable, factors for the start of pregnancy. Good diabetes care for women of childbearing age should include taking into consideration a possible pregnancy.