Pregnant women ostensibly suffer from blood clot in left-leg, say experts

Lead researcher, Wee-Shian Chan, MD, Women’s College Hospital said, “Anatomic distribution of deep vein thrombosis in pregnant women, and perhaps the pathophysiology of the condition, may indeed differ from that reported in the general population.”

Six studies reviewed
The research team at Women’s College Hospital evaluated 1,098 papers and eventually reviewed six studies with 124 pregnant women diagnosed with DVT.

For the study, the team did a synopsis of the subjects’ records relating to the side of the thrombosis, the anatomic circulation of the thrombosis and the involvement of each segment of veins during DVT diagnosis.

The subjects were divided into cohorts comprising three or more subjects in each group and were diagnosed using compression ultrasonography, MRI, CT or venography scans.

Compression ultrasonography is a comparatively insensitive method to venography, for diagnosing DVT of the calf and isolated iliac vein thrombosis--occurring in the pelvis bone.

Findings of the literature review
Analysis revealed that 84 of 96 patients (88 percent) reported involvement of the left leg, with 87 of 122 thrombosis (71 percent) limited to the proximal veins, without any involvement of the calf veins.

It was further revealed that out of these 87, 56 thrombosis (64 percent) were limited to the iliac or femoral or thigh vein.

Researchers also found over-weight mothers of over 35 years of age, with immobility prior to labor or an infection were at high risk of DVT during pregnancy.

“In addition to what was previously known--that left-sided deep vein thrombosis is more common in pregnancy--we also found that proximal deep vein thrombosis, restricted to the femoral or iliac veins, is also more common,” stated the researchers.

Explanation of the results
Researchers explained that the May-Thurner-like syndrome caused due to compression of the left iliac vein by the fetus--during crossing the right iliac artery increase the odds of iliofemoral deep vein thrombosis in late pregnancy.

However, they added, “Thrombosis occurs with equal frequency in all trimesters, so this hypothesis wouldn’t apply to deep vein thrombosis in early pregnancy.”

The study appears online in the Canadian Medical Association Journal.