YEARS Algorithm appears to be possible viable clinical decision tool to rule out PE in pregnant patients . MDCalc link.
utilizes d dimer test and presence of three YEARS criteria: clinical signs of DVT, hemoptysis, PE as most likely diagnosis
clinical sign of DVT with positive US LE, initiate anticoagulant treatment
clinical sign of DVT with negative US LE, into algorithm
No YEARS criteria with d dimer <1000, PE ruled out
No YEARS criteria with d dimer >1000, CTA
1-3 YEARS criteria with d dimer <500, PE ruled out
1-3 YEARS criteria with d dimer >500 , CTA
utilizes d dimer test and presence of three YEARS criteria: clinical signs of DVT, hemoptysis, PE as most likely diagnosis
clinical sign of DVT with positive US LE, initiate anticoagulant treatment
clinical sign of DVT with negative US LE, into algorithm
No YEARS criteria with d dimer <1000, PE ruled out
No YEARS criteria with d dimer >1000, CTA
1-3 YEARS criteria with d dimer <500, PE ruled out
1-3 YEARS criteria with d dimer >500 , CTA
Begin with bilateral lower extremity duplex scan
if positive→treat empirically for PE
if negative→CTA
CTA and V/Q scans yield approximately 0.025 rad and 0.040 rad respectively to the fetus
>5 rads is considered teratogenic
However, 20-100 times more radiation is delivered to maternal breast tissue with CT, increasing the risk of breast cancer
Up to 17% of pregnant patients have isolated pelvic DVT(not found with ultrasound)
if positive→treat empirically for PE
if negative→CTA
CTA and V/Q scans yield approximately 0.025 rad and 0.040 rad respectively to the fetus
>5 rads is considered teratogenic
However, 20-100 times more radiation is delivered to maternal breast tissue with CT, increasing the risk of breast cancer
CTA and V/Q scans yield approximately 0.025 rad and 0.040 rad respectively to the fetus
>5 rads is considered teratogenic
However, 20-100 times more radiation is delivered to maternal breast tissue with CT, increasing the risk of breast cancer
D-dimer is not recommended for excluding PE (weak recommendation, very-low-quality evidence).
If signs and symptoms of deep venous thrombosis (DVT), first perform bilateral venous compression ultrasound (CUS) of lower extremities, followed by anticoagulation treatment if positive and by further testing if negative (weak recommendation, very-low-quality evidence).
If no signs and symptoms of DVT,<unk>  vascular imaging should be used over bilateral lower extremity ultrasounds(weak recommendation, very-low-quality evidence).
D-Dimer MAY BE used with following limits with very poor evidence
1st trimester: <750 ng/mL (+50% increase from normal lab threshold)
2nd trimester: <1000 ng/mL (+100% from normal)
3rd trimester: <1250 ng/mL (+150% from normal)
YEARS Algorithm
3-month incidence of VTE of pregnant patients without CTPA was 0.43%
Pregnancy-adapted YEARS algorithm recommends initiation of anticoagulation in positive US compression of symptomatic leg should there be signs of DVT
Pregnancy-adapted YEARS algorithm <unk><unk>  was safely ruled out by the pregnancy-adapted YEARS diagnostic algorithm across all trimesters of pregnancy. CT<unk>  angiography was avoided in 32 to 65% of patients"
efficiency of algorithm highest during first trimester and lowest during third
1st trimester: <750 ng/mL (+50% increase from normal lab threshold)
2nd trimester: <1000 ng/mL (+100% from normal)
3rd trimester: <1250 ng/mL (+150% from normal)
3-month incidence of VTE of pregnant patients without CTPA was 0.43%
Pregnancy-adapted YEARS algorithm recommends initiation of anticoagulation in positive US compression of symptomatic leg should there be signs of DVT
Pregnancy-adapted YEARS algorithm <unk><unk>  was safely ruled out by the pregnancy-adapted YEARS diagnostic algorithm across all trimesters of pregnancy. CT<unk>  angiography was avoided in 32 to 65% of patients"
efficiency of algorithm highest during first trimester and lowest during third
efficiency of algorithm highest during first trimester and lowest during third
Pulmonary embolism in pregnancy
Acute coronary syndromes 
Cardiac arrest in pregnancy
STEMI
Comorbid diseases in pregnancy
Non-STEMI
Abdominal pain in pregnancy
Unstable angina