The average risk of venous thromboembolism (VTE) in long haul travellers is approximately 2.8 per 1000 travellers, which is increased in the presence of other VTE risk factors. In pregnant long-haul travellers, little is known in terms of the absolute risk of VTE in these women and, therefore, there is limited consensus on appropriate thromboprophylaxis in this setting.

This review will provide guidance to allow practitioners to safely minimize the risk of travel-related VTE in pregnant women. The suggestions provided are based on limited data, extrapolated risk estimates of VTE in pregnant travellers and recommendations from published guidelines.

We found that the absolute VTE risk per flight appears to be <1% for the average pregnant or postpartum traveller. In pregnant travellers with a prior history of VTE, a potent thrombophilia or strong antepartum risk factors (e.g. combination of obesity and immobility), the risk of VTE with travel appears to be >1%. Postpartum, the risk of VTE with travel may be >1% for women with thrombophilias (particularly in those with a family history) and other transient risk factors and in women with a prior VTE.

Based on our findings, we recommend simple measures be taken by all pregnant travellers, such as frequent ambulation, hydration and calf exercises. In those at an intermediate risk, we suggest a consideration of 20-30 mmHg compression stockings. In the highest risk group, we suggest careful consideration for low-molecular-weight heparin thromboprophylaxis. If there are specific concerns, we advise consultation with a thrombosis expert at the nearest local centre.

Venous thromboembolism (VTE), referring to both deep vein thrombosis and pulmonary embolism, is a leading cause of death in the developed world during pregnancy. This increased risk is attributed to the Virchow triad, inherited thrombophilias, along with other standard risk factors, and continues for up to 6 to 12 weeks postpartum. During the peripartum period, women should be risk stratified and preventive measures should be initiated based on their risk. Diagnostic tests and treatment strategies commonly used in VTE differ in pregnancy. An understanding of these differences is imperative to diagnose with confidence and to treat appropriately.

Pulmonary contrast enhanced magnetic resonance angiography (CE-MRA) is useful for the primary diagnosis of pulmonary embolism (PE). Many sites have chosen not to use CE-MRA as a first line of diagnostic tool for PE because of the speed and higher efficacy of computerized tomographic angiography (CTA). In this review, we discuss the strengths and weaknesses of CE-MRA and the appropriate imaging scenarios for the primary diagnosis of PE derived from our unique multi-institutional experience in this area. The optimal patient for this test has a low to intermediate suspicion for PE based on clinical decision rules. Patients in extremis are not candidates for this test. Younger women (< 35 years of age) and patients with iodinated contrast allergies are best served by using this modality We discuss the history of the use of this test, recent technical innovations, artifacts, direct and indirect findings for PE, ancillary findings, and the effectiveness (patient outcomes) of CE-MRA for the exclusion of PE. Current outcomes data shows that CE-MRA and NM V/Q scans are effective alternative tests to CTA for the primary diagnosis of PE.