MRCP revision battle 37.2: DVT/PE in pregnancy

It is one of those unfortunate situations: pregnancy makes DVT/PE more likely (increases risk around 6x), but the presence of a fetus also makes your preferred investigative tests more risky.


Risk is more increased if:

• >35 yrs
• higher parity
• raised BMI
• smoker
• sickle cell
• anaemic
• dehydration
• not blood group O

The consensus on management of ?PE in pregnancy seems to be:

• CXR in all cases
• compression doppler in all cases - if this shows DVT you can just treat without needing to investigate further

In terms of the next investigation if you clinically suspect PE but the doppler is normal there is a lack of consensus:

• CTPA delivers 10-30% less radiation to the fetus but
• V/Q scan causes less radiation to the maternal breast tissue

In general CTPA seems to 'win'



Note that d-dimer is usually 'normal' in the first trimester of pregnancy, rises in the second to third and then returns to baseline at 4-6 weeks post-partum.  However, it is generally not recommended as an investigation in pregnant women.



Treatment for DVT/PE in pregnancy is LMWH, continued for 6 months (with at least 6 weeks of anticoagulation post-partum)

For the really keen:

Patient plus article on DVT/PE in pregnancy

Next... MRCP revision battle 37.3...