In most cases, warfarin can be started on the same day as heparin. Warfarin and heparin should overlap for at least 5 days or until the INR value is within therapeutic range for two consecutive days before heparin is discontinued. Therapeutic heparin can be achieved by subcutaneous injections twice daily. Heparin should be stopped at the first sign of labour. Secondary prevention in the post-partum period can be achieved with warfarin or SC heparin and is recommended for at least 6 weeks after delivery.
Women can breast feed while being treated with warfarin therapy.
The management of pregnant women who have previously had a DVT or PE is controversial. Adverse Effects Bleeding is the most common adverse effect of heparin. If major bleeding occurs, discontinue heparin. With less critical bleeding, doses should be adjusted and underlying causes investigated. Osteoporosis is a serious, but less common side-effect associated with prolonged use of high doses of heparin.