30th June 2023

Thromboembolic disease

The physiological changes of pregnancy increase the risk of thromboembolic disease both antenatally and, significantly, for the first six weeks after delivery. Depending on risk factors, women may be offered LMWH from booking, 28/40, or from delivery for ten days or six weeks.

Acute management of VTE

Given the increased risk of VTE in pregnancy, any woman presenting with symptoms suggestive of VTE should be started on treatment dose LMWH and have urgent investigations. The treatment dose in pregnancy is approximately 1mg/kg BD or 1.5mg/kg OD. Before starting on anticoagulants, baseline FBC, U&E, LFTs and clotting are taken. D-dimer should not be performed as pre-test probability scores are not validated in pregnancy.

DVT: if DVT is suspected, a compression duplex ultrasound should be performed. If negative but suspicion is high, LMWH should be continued, and a further scan performed on days 3 and 7. If iliac vein thrombosis is suspected MRI may be used.

PE: Women with suspected PE should have a CXR and ECG. If they also have signs of a DVT, compression duplex ultrasound should be done; if this is positive, no further investigations are required. If the CXR is abnormal, a CTPA in preference to a V/Q scan should be carried out.

Life-threatening PE: IV unfractionated heparin, thrombolysis, thoracotomy and surgical embolectomy are all options for treatment. If stable, unfractionated heparin is first line. If there is evidence of significant haemodynamic compromise, thrombolysis should be offered.