Diabetics should remember that birth control pills alter a woman's hormonal levels. In this sense, high doses of hormones can have a negative impact on blood sugar levels, which can make it harder for them to control their diabetes.
Moreover, there is an increased risk for heart attack or stroke among women who use the pill, a risk that is higher in the case of diabetics. This applies to other types of hormonal contraception such as Depo-Provera, the contraceptive implant, the patch and the vaginal ring.
Intrauterine devices are neither indicated for diabetics because they increase the risk of developing infections in the uterus, a risk which is already higher among women with type 2 diabetes.
Female sterilization by means of tubal ligation is, outside of abstinence, perhaps the most secure method for diabetics, as it does not affect a woman's blood sugar levels. However, surgery is not without risk, and women should keep in mind that it is a permanent method of birth control, which in many cases cannot be reversed.