Validation of Ultrasound in Predicting a Low Lying Placenta Throughout Pregnancy

Study Outcome Measurement and Ascertainment:

Data will be collected from data in EPIC and UTMB electronic medical records. This
information will include:

1. Maternal demographic data, medical, family, personal, social and surgical history

2. Maternal pre-pregnancy weight and height

3. Maternal weight at time of delivery

4. Maternal weight on post-operative day 1

5. Gestational age at delivery, infant gender, birth weight, placental weight, delivery
method, and complications through 6 weeks postpartum.

Venous hemodynamics will be obtained using venous duplex ultrasound. 1. Peak, mean, and
minimum flow velocities and diameter will be obtained. Calculations of venous velocity
amplitude, cross-sectional area, and shear stress will be made from the data collected.

Study Procedures:

This is a prospective study using duplex ultrasound techniques to characterize venous flow
in obese and non-obese pregnant patients. Women will be consented to participate and then
separated into a study group of obese women (BMI >/= 30) and a control group of non-obese
women (BMI <30). These women will be admitted to Labor and Delivery for management of
pregnancy. The Doppler US will then be performed by trained staff on the lower extremity.
The flow data described above will be measured and compared between the two groups.
Additional measurements will be collected during hospitalization.

Criteria for Inclusion of Subjects:

-Age >/= 18 years of age, planned delivery at John Sealy Hospital (JSH)

Criteria for Exclusion of Subjects:

- <18 years of age

- Personal history of VTE, regardless of etiology

- Development of VTE during this pregnancy -History of thrombophilia, bleeding disorder
marked varicosities, history of recurrent stillbirth, intrauterine growth restriction

- Any indication for emergency delivery

- Known major fetal abnormality or genetic syndrome

Sources of Research Material:

The sources of data to be used include maternal medical records from EPIC as well as the
data obtained from the venous ultrasound.

Recruitment Methods and Consenting Process:

The subjects will be pregnant women who plan a delivery at JSH. Subjects will be consented
by study personnel. Patients will not receive any monetary gain. They will understand that
this is voluntary and will not affect their care.

Potential Risks:

The Doppler velocimetry is the modality that has been used in pregnancy to assess for the
presence of DVT, thus, the safety has been assessed and widely studied. This poses minimum
risk to the mother or to the fetus.

Subject Safety and Data Monitoring:

This study does not place subjects at risk of their safety. This modality is well studied to
be safe in pregnancy.

Data monitoring will be performed only by study personnel. Data may be assessed prior to the
study being completed to assess to see if statistical analysis reveals any difference and if
the study can be stopped early.

Procedures to Maintain Confidentiality:

Data will only be viewed by study personnel. The data will then be de-identified and a study
number will be assigned to each patient. The patient's identity will then be secured on an
UTMB encrypted laptop device and a hard copy stored in the locked file cabinet in the locked
office of the investigator.

Potential Benefits:

There are no benefits to subjects participating in the study. By gathering the information
of duplex velocimetry in both the obese and non-obese population we can determine if there
is a change in the velocimetry in this at risk population.

Inclusion Criteria:

- Age >/= 18 years of age, planned delivery at John Sealy Hospital (JSH)

Exclusion Criteria:

- <18 years of age

- Personal history of VTE, regardless of etiology

- Development of VTE during this pregnancy -History of thrombophilia, bleeding disorder
marked varicosities, history of recurrent stillbirth, intrauterine growth restriction

- Any indication for emergency delivery

- Known major fetal abnormality or genetic syndrome