Pregnancy losses in women with Type 1 or Type 2 diabetes in the UK: an investigation using primary care records

Aim This study aims to investigate pregnancy losses in women with Type 1 or Type 2 diabetes and compare this with the general population. Methods Pregnancies ending between 1993 and 2006 in those with Type 1 or Type 2 diabetes were identified on the General Practice Research Database. Pregnancy losses were identified from medical records and the cohort described by their characteristics and prescribing for diabetes. Results Of 2001 pregnancies identified in women with Type 1 diabetes, 678 ended in a pregnancy loss: 19.6% were spontaneous, 9.6% were induced and 4.3% were losses for unknown reasons. In women with Type 2 diabetes, there were 240 losses in 669 pregnancies: 21.1% were spontaneous, 10.3% induced and 4.0% were losses for unknown reasons. The proportion of spontaneous losses in women with diabetes was higher than in the general population (13.2%). Women with Type 1 diabetes treated with human and analogue insulins were 60% more likely to have a delivery than a loss (odds ratio 1.6, 95% CI 1.18–2.18) compared with human insulin treatment alone, although numbers were small. Conclusion We found that the proportions of spontaneous losses in women with Type 1 or Type 2 diabetes were similar at approximately 20%, which is higher than in the general population and also higher than previous studies have reported. While much emphasis has been placed on pre‐conception care for women with Type 1 diabetes, the same is now needed for those with Type 2 diabetes, given the similarity in outcomes and increasing prevalence of this condition. What's new? Proportions of pregnancies resulting in deliveries and losses in women with Type 2 diabetes were similar to those in women with Type 1 diabetes. Using primary care records we found higher overall proportions of losses than have previously been reported (Type 1 33.4%, Type 2 35.4%) and higher proportions of spontaneous losses (Type 1 19.6%, Type 2 21.1%) than in the general population (13.2%). Oral treatment of Type 2 diabetes in the 3 months before pregnancy start date or during the first trimester resulted in the highest proportion of spontaneous losses (25%).