Methods for administering subcutaneous heparin during pregnancy

There is no evidence from randomised controlled trials to evaluate the best method of administering subcutaneous heparin to pregnant women.

Pregnant women have an increased risk of venous thromboembolism (VTE) when compared with non-pregnant women because of changes in blood clotting. VTE includes deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT is a clot in the deep veins of the leg blocking blood flow; parts of the clot may break away and be carried in the blood to the lungs, to form a PE. DVT is potentially, and PE is definitely, life-threatening for both mother and baby. Pregnant women with a history of VTE, antithrombin deficiency, or other risk factors for VTE are at an even greater risk and need heparin for prevention of VTE (prophylaxis). Although receiving subcutaneous heparin (either unfractionated heparin (UFH) or low molecular weight heparin (LMWH)) is the main option in the prevention of VTE during pregnancy, the management of thromboprophylaxis in pregnant women has mostly relied on the evidence from non-pregnant participants. Methods of receiving heparin subcutaneously include giving an injection at regular intervals, or using an indwelling catheter and an infusion pump. Women's satisfaction with receiving subcutaneous heparin is highly important as thromboprophylaxis in pregnancy involves a cost burden, inconvenience, and side effects as a result of a longer duration. Some women  may not self-administer heparin and must rely on others to give them their injections otherwise they stop using the heparin, thus exposing themselves to an increased risk of VTE. However, this review found no randomised controlled trials to show which methods of receiving subcutaneous heparin are effective and safe for pregnant women.

Authors' conclusions: 

There is no evidence from randomised controlled trials to evaluate the effectiveness and safety of different methods of administering subcutaneous heparin (UFH or LMWH) to pregnant women.

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Background: 

Pregnant women with a history of venous thromboembolism (VTE), antithrombin deficiency, or other risk factors for VTE, need heparin (unfractionated heparin (UFH) or low-molecular weight heparin (LMWH)) prophylaxis, mainly through administering subcutaneously. Several methods of administering heparin (UFH or LMWH) subcutaneously have been introduced to prevent adverse pregnant outcomes. The effectiveness and safety of different methods administering subcutaneous heparin (UFH or LMWH) during pregnancy have not been systematically evaluated.

Objectives: 

To compare the effectiveness and safety of different methods of administering subcutaneous heparin (UFH or LMWH) to pregnant women.

Search strategy: 

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2013) and reference lists of retrieved studies.

Selection criteria: 

All randomised controlled trials (individual and cluster) comparing the effectiveness and safety of different methods of administering subcutaneous heparin (UFH or LMWH) during pregnancy. Studies reported only as abstracts were eligible for inclusion and would have been placed in studies awaiting assessment, pending the full publication of their results. Quasi-randomised studies and cross-over trials were not eligible for inclusion..

Methods of administering subcutaneous heparin include intermittent injections versus indwelling catheters or programmable (auto) external infusion pumps, or any other devices to facilitate the subcutaneous administration of heparin (UFH or LMWH) during pregnancy.

Data collection and analysis: 

If eligible trials had been identified, trial quality would have been assessed and data extracted, unblinded by review authors independently.

Main results: 

No trials met the inclusion criteria for the review.