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PubMed This is a summary of 11 peer-reviewed journal articles Updated
Hematology · Antithrombin Deficiency

What is Safe Birth Control for Antithrombin Deficiency?

At a Glance

Women with antithrombin deficiency should avoid estrogen-containing birth control due to a high risk of blood clots. Safe, highly effective alternatives include the non-hormonal copper IUD, barrier methods, and progestin-only options like hormonal IUDs, the implant, and the mini-pill.

In this answer

4 sections

01

Non-Hormonal Contraception

02

Progestin-Only Hormonal Methods

03

Managing Periods and Blood Thinners

04

Building Your Care Team

If you have antithrombin deficiency, you already know that your condition significantly increases your risk of developing blood clots (venous thromboembolism) [1][2]. Because estrogen further increases this risk, combination (estrogen-containing) birth control pills, patches, and rings are generally unsafe and should be avoided [3][4].

However, you still have several highly effective, safe options for preventing pregnancy. Both non-hormonal methods and progestin-only contraceptives are considered safe alternatives because they do not carry the blood clot risks associated with estrogen [5][4].

Non-Hormonal Contraception

Since they contain no hormones at all, non-hormonal methods carry zero risk of causing hormone-related blood clots [4]. They are often considered the absolute safest choices for women with severe hereditary thrombophilias [1][3].

  • The Copper IUD (Paragard): This is a highly effective, long-acting device inserted into the uterus. It provides years of pregnancy prevention without any hormones.
  • Barrier Methods: Condoms, diaphragms, and cervical caps are completely safe, though they are less effective at preventing pregnancy than IUDs or implants.

Progestin-Only Hormonal Methods

Unlike estrogen, the hormone progestin does not significantly increase your risk of blood clots [5][4]. For this reason, progestin-only methods are widely recommended as first-line hormonal options for women with antithrombin deficiency [6].

  • Hormonal IUDs (e.g., Mirena, Kyleena, Liletta): These levonorgestrel intrauterine systems release a small amount of progestin directly into the uterus. They are highly effective at preventing pregnancy.
  • The Contraceptive Implant (Nexplanon): A small rod placed under the skin of your arm that releases progestin. It is one of the most effective methods of birth control available.
  • The “Mini-Pill” (Progestin-Only Pill): A daily pill that contains only progestin, making it a safer oral option than combination pills [5][4].
  • The Birth Control Shot (Depo-Provera): While this is also a progestin-only method, its specific hormone dose may carry a slightly different risk profile than other progestin methods. You should explicitly discuss its safety with your hematologist before choosing this option [7].

A Note on Emergency Contraception

If you rely on barrier methods and experience a failure (like a broken condom), you may wonder if emergency contraception is safe. Because standard emergency contraceptive pills like Plan B are progestin-only (levonorgestrel), they are generally considered safe for women who cannot take estrogen [5].

Managing Periods and Blood Thinners

When choosing between these safe options, it is important to think about your menstrual bleeding, especially if you take prescription blood thinners (anticoagulants) for your antithrombin deficiency.

Contraceptive Method Hormone Type Expected Impact on Menstrual Bleeding
Copper IUD (Paragard) None Often causes heavier, longer periods [8].
Hormonal IUD (Mirena) Progestin-only Frequently reduces menstrual bleeding and cramping [9][10].
  • Heavy Bleeding Risk: Blood thinners can make your periods heavier. Because the copper IUD is also known to sometimes cause heavier or longer periods, combining a copper IUD with blood thinners might result in uncomfortably heavy bleeding for some women [8].
  • Lighter Periods: Hormonal IUDs like Mirena are frequently associated with a significant reduction in menstrual bleeding [9][10]. If minimizing blood loss is a priority for you, a hormonal IUD might be a better choice [8].

Building Your Care Team

Choosing the right birth control is not a decision you should make with just one doctor. Multidisciplinary management—meaning a coordinated approach between your doctors—is essential for women with congenital antithrombin deficiency [1][11].

Before starting any new contraceptive method, you should have a combined consultation involving both:

  1. Your Hematologist: To evaluate your current, personalized risk for blood clots and manage any blood-thinning medications [11].
  2. Your OB/GYN: To discuss the practical aspects of insertion, side effects, and pregnancy prevention.

Together, they can help you select the method that best balances your need for effective birth control, your period preferences, and your safety.

Common questions in this guide

Can I take standard birth control pills if I have antithrombin deficiency?
No, combination birth control pills that contain estrogen are generally unsafe. Estrogen significantly increases your already elevated risk of developing abnormal blood clots.
Are IUDs safe for women with antithrombin deficiency?
Yes, both the non-hormonal copper IUD and progestin-only hormonal IUDs are considered safe, highly-effective options. Hormonal IUDs may also help reduce heavy menstrual bleeding, which is especially helpful if you take blood thinners.
Is the morning-after pill safe if I have a history of blood clots?
Yes, standard emergency contraception pills like Plan B contain only progestin. Because they do not contain estrogen, they are generally considered safe for women who are at a high risk of developing blood clots.
How do blood thinners affect my birth control choices?
Blood thinners can cause heavier menstrual bleeding. Because the copper IUD can also increase period flow, women on blood thinners may prefer a hormonal IUD, which is frequently associated with lighter periods and less cramping.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on my personal history and antithrombin levels, is there any reason I should avoid a progestin-only method?
  2. 2.If I am currently taking blood thinners, how might a copper IUD versus a hormonal IUD affect my periods?
  3. 3.If I choose an IUD or implant, do I need to pause my blood thinners before the insertion procedure?
  4. 4.How do you and my hematologist plan to coordinate my care and monitor my health while I am on this contraceptive?
  5. 5.Is progestin-only emergency contraception (like Plan B) safe for me to use in the event of a barrier method failure?

Questions For You

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References

References (11)
  1. 1

    Management of antithrombin deficiency: an update for clinicians.

    Bravo-Pérez C, Vicente V, Corral J

    Expert review of hematology 2019; (12(6)):397-405 doi:10.1080/17474086.2019.1611424.

    PMID: 31116611
  2. 2

    Prevalence and Outcomes of Thrombophilia in Patients with Acute Pulmonary Embolism.

    Obaid M, El-Menyar A, Asim M, Al-Thani H

    Vascular health and risk management 2020; (16()):75-85 doi:10.2147/VHRM.S241649.

    PMID: 32214817
  3. 3

    Primary and secondary thrombophiliа: pathogenesis, clinical presentation, approaches to thrombotic complications prevention and treatment.

    Bereziuk OM, Mazur JV, Berko GK, et al.

    Wiadomosci lekarskie (Warsaw, Poland : 1960) 2019; (72(5 cz 1)):908-913.

    PMID: 31175794
  4. 4

    Birth Control Pills and Thrombotic Risks: Differences of Contraception Methods with and without Estrogen.

    Rott H

    Hamostaseologie 2019; (39(1)):42-48 doi:10.1055/s-0039-1677806.

    PMID: 30669160
  5. 5

    Progestin-only contraception is first line for sickle cell disease: a comment on "Hormonal therapies in females with blood disorders: thrombophilia, thrombosis, hemoglobinopathies, and anemias."

    Pecker LH, Burke A, Streiff MB, et al.

    Research and practice in thrombosis and haemostasis 2023; (7(6)):102183 doi:10.1016/j.rpth.2023.102183.

    PMID: 37711908
  6. 6

    Estrogen, progestin, and beyond: thrombotic risk and contraceptive choices.

    Skeith L, Bates SM

    Hematology. American Society of Hematology. Education Program 2024; (2024(1)):644-651 doi:10.1182/hematology.2024000591.

    PMID: 39644023
  7. 7

    Guidance for the evaluation and treatment of hereditary and acquired thrombophilia.

    Stevens SM, Woller SC, Bauer KA, et al.

    Journal of thrombosis and thrombolysis 2016; (41(1)):154-64 doi:10.1007/s11239-015-1316-1.

    PMID: 26780744
  8. 8

    Effects of a levonorgestrel intrauterine system versus a copper intrauterine device on menstrual changes and uterine artery Doppler.

    Rezk M, Elshamy E, Shaheen AE, et al.

    International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics 2019; (145(1)):18-22 doi:10.1002/ijgo.12778.

    PMID: 30706471
  9. 9

    Effectiveness of Levonorgestrel Releasing Intrauterine System in Perimenopausal Women with Heavy Menstrual Bleeding: A Prospective Study at a Teaching Hospital in India.

    Nidhi , Kumari A, Tirkey S, Prakash J

    Journal of menopausal medicine 2022; (28(3)):128-135 doi:10.6118/jmm.22025.

    PMID: 36647276
  10. 10

    Bleeding pattern difference between levonorgestrel intrauterine system and copper intrauterine devices inserted immediately post-abortion: a multicenter, prospective, observational cohort study in Chinese women.

    Chen X, Li Q, Wang X, et al.

    Current medical research and opinion 2018; (34(5)):873-880 doi:10.1080/03007995.2017.1421919.

    PMID: 29298525
  11. 11

    Genetic and clinical characterization of two families with severe venous thromboembolism due to nonsense mutations in the SERPINC1 gene.

    Wei X, Chen W, Zhang J, Mao J

    Thrombosis journal 2025; (23(1)):118 doi:10.1186/s12959-025-00803-y.

    PMID: 41366676

This page provides educational information about birth control options for antithrombin deficiency. Always consult your hematologist and OB/GYN to determine the safest contraceptive method for your specific health needs.

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