After initial admission of the patients for Cesarean Section, Vaginal Delivery or any
other antepartum hospitalization, patients undergo extensive counseling regarding various
aspects of the Duplex Ultrasonography procedure and the purpose of the study for
screening of the venous thrombosis in asymptomatic patients. Patients electing to proceed
will have written informed consent obtained and their baseline demographic and medical
characteristics recorded. 48-72 hours after Cesarean Section, 24-48 hours after vaginal
delivery and 48 to 72 hours after antepartum hospitalization, participants also undergo a
bilateral lower extremity Venous Ultrasonographic examination which is the standard
diagnostic procedure for detecting the VTE of the lower limbs. The latter group will be
re-scanned 14-21 days and, when feasible, 45 days after admission.
The compression ultrasound study will be performed by post-doctoral research fellows, who
will be formally trained for lower extremity ultrasound, under direct supervision.
Diagnostic Criteria and Interpretation · The gray scale compression sonographic findings
of acute DVT are based on direct visualization of the thrombus and lack of venous
compressibility. Altered luminal echogenicity and alterations in flow characteristics are
secondary signs. · Visualization of thrombus is variable, depending on the extent, age,
and echogenicity (ranging from anechoic to complex) of the clot. · in case of thrombosis,
Each Doppler image should demonstrate spontaneous and phasic flow. · Loss of phasic
variation suggests proximal obstruction (intrinsic or extrinsic). · Prominent pulsations
can be due to right sided heart failure and may be a manifestation of tricuspid valve
regurgitation. Normal - Vein is totally compressible. Duplex Doppler reveals spontaneous
phasic waveform Acute DVT - Vein is non compressible, but deformable and smooth. Vein is
generally distended, with or without luminal echoes. The thrombus can be free floating.
Spectral Doppler may be normal, continuous, or not present
If no DVT is seen on ultrasonography, then participants will be followed up clinically
throughout the remainder of their hospitalization without further intervention.
Participants with a DVT in the deep venous circulation will be referred to radiology for
confirmation and if positive for DVT the patient will be offered treatment per current
clinical guidelines for symptomatic DVT. This was the approach taken in most similar
studies involving detection of DVT in asymptomatic non-pregnant women.
If a VTE is seen in the superficial veins of the lower extremity, another lower extremity
venous Ultrasonographic evaluation will be scheduled 48 hours later. If a persistent
superficial VTE is seen, the patient will be referred for evaluation and therapy per
current clinical guidelines.
Ultrasound procedure data and all the information related to the findings of this study
like the reports, ultrasound pictures or demographic informations will be stored in the
subject's medical records which will be created specifically for this study.
All the imaging will be reviewed blindly by one sonographer and one radiologist for image
quality. If the image is not qualified and patient is still at hospital will redo the
Doppler ultrasound. if the patient is discharged will exclude that patient from the
study.
We will also collect demographic data and other clinical information of the patient such
as maternal age, prenatal records, ultrasounds reports at different gestational age,
consultations, maternal past medical history, maternal past obstetrical history,
medications receive during pregnancy, gestational age at the time of procedure, first
manifestation of the DVT, treatments, process of these conditions, outcome, gestational
age at birth, fetal anomalies, early neonatal outcome.
