What is the effect of anticoagulation (anti-coagulant therapy) on fertility?

From the Guidelines

Anticoagulation therapy generally does not have a direct negative effect on fertility in either men or women. Common anticoagulants like warfarin, heparin, low molecular weight heparins (such as enoxaparin), and direct oral anticoagulants (DOACs) like apixaban, rivaroxaban, and dabigatran do not appear to impair the ability to conceive 1. However, anticoagulation management becomes important when planning pregnancy. For women requiring long-term anticoagulation who are trying to conceive, low molecular weight heparin is typically preferred over warfarin, as warfarin crosses the placenta and can cause birth defects, particularly when used between weeks 6-12 of pregnancy.

Some key points to consider:

• DOACs are not recommended during pregnancy due to limited safety data 1.
• Men taking anticoagulants do not need to modify their therapy when trying to conceive, as these medications do not affect sperm production or quality.
• The underlying condition requiring anticoagulation (such as antiphospholipid syndrome or thrombophilia) may sometimes impact fertility more than the anticoagulant medication itself, as noted in guidelines for antithrombotic therapy in pregnant women 1.
• Patients on anticoagulation who are planning pregnancy should consult with both their hematologist and reproductive specialist to develop an appropriate management plan that balances thrombotic risk with pregnancy safety. It's also worth noting that animal studies with apixaban do not indicate reproductive toxicity, although the use of apixaban in pregnancy is generally recommended against 1.

From the FDA Drug Label

Dabigatran has been shown to decrease the number of implantations when male and female rats were treated at a dosage of 70 mg/kg (about 2.6 to 3. 0 times the human exposure at MRHD of 300 mg/day based on area under the curve [AUC] comparisons) prior to mating and up to implantation (gestation Day 6). Females of reproductive potential requiring anticoagulation should discuss pregnancy planning with their physician The risk of clinically significant uterine bleeding, potentially requiring gynecological surgical interventions, identified with oral anticoagulants including dabigatran etexilate capsules should be assessed in females of reproductive potential and those with abnormal uterine bleeding. Ovarian (corpus luteum) hemorrhage developed in a number of women of reproductive age receiving short- or long-term anticoagulant therapy.

The effect of anticoagulation on fertility is not well established. Animal studies suggest that dabigatran may decrease the number of implantations 2. In humans, the risk of uterine bleeding and other complications should be assessed in females of reproductive potential 2. Additionally, ovarian hemorrhage has been reported in women receiving anticoagulant therapy 3. However, the direct impact of anticoagulation on fertility is not clearly stated in the provided drug labels. Key points to consider:

• Animal studies suggest a potential decrease in implantations
• Risk of uterine bleeding and other complications in females of reproductive potential
• Ovarian hemorrhage has been reported in women receiving anticoagulant therapy It is essential to discuss pregnancy planning with a physician for females of reproductive potential requiring anticoagulation 2.

From the Research

Effect of Anticoagulation on Fertility

• The use of anticoagulants in pregnancy is a complex issue, with women being prone to thromboembolism during pregnancy and at the same time being at risk of bleeding, especially during delivery 4.
• Anticoagulant therapy is used to prevent and treat various pregnancy complications such as thrombotic events, preeclampsia, and pregnancy loss 4, 5.
• Studies have shown that the use of low molecular weight heparins, such as enoxaparin, can be effective in preventing pregnancy loss in women with inherited and acquired thrombophilia 6, 7.
• Enoxaparin has been found to be safe and effective in preventing pregnancy loss, with a significant reduction in pregnancy loss rates compared to untreated controls 6, 7.
• The safety and efficacy of enoxaparin in pregnancy have been evaluated in several studies, with findings suggesting that it is associated with significantly lower complications than aspirin 7.
• Anticoagulant therapy during pregnancy requires careful consideration of the risks and benefits, with the goal of balancing therapeutic benefit versus maternal and fetal risks 5, 8.

Indications for Anticoagulation Therapy

• Anticoagulant therapy is indicated for the treatment of acute thrombotic events and prophylaxis for those at increased risk of thrombotic events 5.
• The use of antiplatelets and anticoagulants during pregnancy is supported by current guidelines, with selective use of aspirin, heparin, and warfarin in pregnant women 8.
• The decision to treat with antiplatelets and anticoagulants during pregnancy requires thoughtful discussion between patient and provider, taking into account the therapeutic benefit versus maternal and fetal risks 8.

Safety and Efficacy of Anticoagulation Therapy

• The safety and efficacy of anticoagulant therapy during pregnancy have been evaluated in several studies, with findings suggesting that it is effective in preventing pregnancy loss and reducing the risk of thrombotic events 6, 7, 5.
• However, anticoagulant therapy during pregnancy is not without risks, with potential side effects including bleeding, thrombocytopenia, and teratogenicity 7, 5.
• The use of enoxaparin during pregnancy has been found to be associated with significantly lower complications than aspirin, with rare reports of thromboembolic events, thrombocytopenia, and congenital malformations 7.