Patterns of contraception in UK women with Type 1 diabetes mellitus: a GP database study

Abstract

Aim: To establish the patterns of contraceptive prescribing for women aged 15-49 with Type 1 diabetes mellitus (DM) and compare them with the patterns in women without diabetes.

Methods: This was a cross-sectional study using a UK primary care database.

Results: Nine hundred and thirty-eight women with a diagnosis of Type 1 DM were identified. A comparison group of women aged 15-49 without diabetes (n = 10000) were randomly selected from the database. Twenty-five per cent of the women with diabetes and 32% without diabetes were prescribed a hormonal contraceptive in 1994. Women with Type 1 DM were more likely to be prescribed a combined oral contraceptive than a progestogen only pill (POP) but were 2.12 (95% CI 1.65-2.72) times more likely to be prescribed a POP than women without diabetes and were less likely to be prescribed a combined pill - odds ratio 0.53 (95% CI 0.44-0.64). The pregnancy rate in women with Type 1 DM over the age of 25 years was lower than for women without diabetes. Women under 25 years with Type 1 DM seemed more likely to record a pregnancy.

Conclusions: Differences between women with Type 1 DM and those without diabetes highlight the variation in the way that GPs and patients evaluate the risks and benefits when deciding on contraception.

PIP: This cross-sectional study using a UK primary care database establishes the patterns of contraceptive prescribing for women aged 15-49 with Type 1 diabetes mellitus (DM) and compares them with the patterns in women without DM. A total of 938 Type 1 DM women were identified and a comparison group of women without diabetes (n = 10,000) were randomly selected from the database. Statistical analysis showed that 25% of the Type 1 DM women and 32% of those without diabetes were prescribed a hormonal contraceptive in 1994. Type 1 DM women were more likely to be prescribed a combined oral contraceptive than a progestogen-only pill (POP). However, they were 2.12 (95% CI, 1.65-2.72) times more likely to be prescribed a POP and less likely to be prescribed a combined pill (odds ratio, 0.53; 95% CI, 1.65-0.64) compared to women without diabetes. In addition, the pregnancy rates in Type 1 DM women over the age of 25 years were lower than in women without diabetes. This finding suggests that Type 1 DM women under age 25 appear more likely to record a pregnancy. In conclusion, differences between Type 1 DM women and those without diabetes highlight the variation in the way that general practitioners and patients evaluate the risks and benefits when deciding on contraception.