WASHINGTON – Women with a history of gestational diabetes can use any contraceptive method safely, and those with uncomplicated pregestational diabetes can also consider all methods, said Anne Burke, MD, director of the family planning division at Johns Hopkins University, Baltimore.
“The real cautions, and some red lights,” apply to those with vascular sequelae, diabetes of 20 years’ duration or more, and patients with other vascular disease in addition to diabetes, she said at the biennial meeting of the Diabetes in Pregnancy Study Group of North America.
“The contraception options for women with diabetes aren’t necessarily terribly limited compared to the options for other women,” Dr. Burke said. “And the big take home is that, across the board, .”
The U.S. Medical Eligibility Criteria for Contraceptive Use issued by the Centers for Disease Control and Prevention assign a 1-4 rating for each method for women with certain characteristics or medical conditions. Category 1 indicates no restrictions, and category 2 means that the advantages generally outweigh theoretical or proven risks. Category 3 indicates that such risks usually outweigh the advantages, and category 4 means there is an unacceptable risk.
Robert Boston/Washington University
The assignment to category 2 instead of category 1 can reflect either limitations in the overall amount of data available or the lack of strong randomized studies “whereas the data [otherwise] seem to support safety,” Dr. Burke said. “And sometimes, it relates to most studies saying one thing and another being a little inconsistent.”
Uncomplicated pregestational diabetes
This is important to understand because all the methods for women with uncomplicated pregestational diabetes (no evidence of vascular disease or end-organ damage) are classified as category 2, except for the copper IUD and emergency contraception, which are in category 1. The document distinguishes between insulin-dependent and non–insulin-dependent diabetes, but the recommendations do not differ between the two categories, she said.
Progestin-only contraceptives appear to have little effect on short- or long-term diabetes control, hemostatic markers, or the lipid profile in women with uncomplicated diabetes. Combined hormonal contraception appears to have no effect on long-term diabetes control or progression to retinopathy; there may be changes in the lipid profile and hemostatic markers, but “mostly within normal values, and in some cases, in a favorable direction,” said Dr. Burke of the department of gynecology and obstetrics at the university.
GDM history
In women who have had gestational diabetes, all methods are in category 1 of the Medical Eligibility Criteria (MEC). While “there have been a couple of question marks” with progestin-only contraceptives and the later development of diabetes, “it seems that there’s really not an increased risk,” she said. Nor does there seem to be an increased risk of developing later diabetes with combined hormonal contraception.
In general, the data backing the MEC come from a limited number of studies, and “few that are rigorously done,” she said. “So the recommendations reflect consensus [that is] based on the best available information.”
Severe or long-standing disease
Data are especially limited for women with more severe and/or long-standing disease, as these women have been excluded from studies. There is enough knowledge, however, to make the hypoestrogenic effects of the depot medroxyprogesterone acetate (DMPA) injectable (Depo-Provera) concerning. “It has a pretty hefty dose of a particular type of progestin that significantly suppresses the hypothalamic-pituitary-ovarian axis – more than other progestin-only methods,” she said. “And we may see some unfavorable lipid changes and changes in carbohydrate metabolism.”
The effects of the DMPA injectable, which is in category 3 for these women, may persist for several months – or longer – after discontinuation, Dr. Burke said. The levonorgestrel IUD, on the other hand, has little effect on diabetes control, hemostatic markers, or lipids; it is in category 2 for these women.
A recently published database analysis found that diabetic users of the DMPA injectable had a hazard ratio for venous thromboembolism of 4.6, compared with IUD users, Dr. Burke said. The study included patients with type 1 and type 2 diabetes (Diabetes Care 2017;40:233-8).
Combined hormonal contraception is assigned to categories 3 and 4 for women with complicated or long-standing diabetes, in part because of thrombosis risk, which “as we know, is slightly elevated even for healthy women,” Dr. Burke said. “There are still quite a few methods that are safe to use without reservation, so here is where we start to move away from combined hormonal methods.”
In addition to the Medical Eligibility Criteria, the CDC has another document, the U.S. Selected Practice Recommendations for Contraceptive Use, also last updated in 2016, which offers “helpful” advice on precontraception tests to perform, timing after pregnancy for starting contraceptive methods, and other issues, Dr. Burke said.
Dr. Burke reported receiving research funding from Bayer, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and Ibis Reproductive Health.