In clinically suspected DVT or PE, treatment with low-molecular-weight heparin (LMWH) should be commenced immediately until the diagnosis is excluded by objective testing, unless treatment is strongly contraindicated.

Compression duplex ultrasound should be undertaken where there is clinical suspicion of DVT.
If ultrasound is negative and there is a low level of clinical suspicion, anticoagulant treatment can be discontinued.

If ultrasound is negative and a high level of clinical suspicion exists, anticoagulant
treatment should be discontinued but the ultrasound should be repeated on days 3 and 7.

Intravenous unfractionated heparin is the preferred, initial treatment in massive PE with cardiovascular compromise.

According to NICE ( Intrapartum care for healthy
women and babies )

• Check blood pressure every 5 minutes for 15 minutes during
  establishment or after further boluses
• Check sensory block hourly
•  Continuous electronic fetal monitoring for 30 minutes during
  establishment or after boluses of 10 ml or more
• Intravenous access should be established prior to commencing regional analgesia.
• Do not administer routine preloading and maintenance fluid

Do not use pad tests in the routine assessment of women with urinary
incontinence.

- For pregnancies at more than 16 weeks of gestation the term low-lying placenta should be used when the placental edge is less than 20 mm from the internal os on transabdominal or transvaginal scanning (TVS).

• The term placenta praevia should be used when the placenta lies directly over the internal os.

The algorithm suggested by RCOG for low lying placenta can be accessed HERE 

In women with suspected PE who also have symptoms and signs of DVT, compression duplex ultrasound should be performed. If compression ultrasonography confirms the presence of DVT, no further investigation is necessary and treatment for VTE should continue.

Pregnant women with suspected PE who have symptoms and signs of DVT should have bilateral compression duplex ultrasound leg studies performed. A diagnosis of DVT may indirectly confirm a diagnosis of PE and since anticoagulant therapy is the same for both conditions, further investigation may not be necessary.

This would limit the radiation doses given to the mother and her fetus.

The algorithm suggested by the RCOG can be viewed HERE