A uterine artery Doppler scan is a specialized pregnancy ultrasound that measures the blood flow in the arteries supplying your womb (uterus). These arteries are responsible for delivering blood to the placenta, which in turn feeds your baby.
This scan is typically performed during your first or second trimester (usually at 11–14 weeks or 20–24 weeks) to assess if your body is adapting well to the pregnancy. It is used as a screening tool to identify if you have an increased risk of developing high blood pressure during pregnancy (pre-eclampsia) or if your baby is at risk of restricted growth.
Common Indications for a Uterine Artery Doppler Scan
- Screening for the risk of pre-eclampsia (pregnancy-induced high blood pressure).
- Identifying risk for fetal growth restriction (babies growing smaller than expected).
- Monitoring pregnancies in women with pre-existing medical conditions like chronic hypertension, kidney disease, or diabetes.
- Checking risk factors in women who had pre-eclampsia or growth-restricted babies in a previous pregnancy.
What exactly does a uterine artery Doppler scan show?
The scan measures the resistance to blood flow in the maternal uterine arteries. In early pregnancy, these arteries should widen to allow a high volume of blood to flow easily. High resistance to blood flow indicates that the womb's blood supply is not adapting fully, which increases the risk of pre-eclampsia.
How should I prepare for a uterine artery Doppler scan?
No special preparation is needed. You do not need to fast. Depending on how far along your pregnancy is, you may be asked to have a partially full bladder for scans done in the first trimester.
Do I need to stop taking medication?
No. Continue taking all your medications. If you are taking low-dose aspirin or other medications to prevent pre-eclampsia, take them as prescribed and tell the scan team.
What happens when I arrive for my scan?
You will lie down on the scan couch in a private room. You will expose your lower abdomen, near your hip bones, where the uterine arteries are located.
How is the procedure performed?
Gel is applied to your lower abdomen. The radiographer will place the probe near the lower left and right sides of your abdomen, close to your groin. They will locate the main uterine arteries and switch to Doppler mode. You will hear the rhythmic, whooshing sounds of your own blood flow. The machine will capture waves on the screen to measure the resistance.
How long does a uterine artery Doppler scan take?
The scan takes about 10 to 15 minutes. It is usually performed at the same time as a routine pregnancy scan.
Is there any discomfort?
You may feel some pressure as the radiographer presses the probe near your hip bones to locate the arteries. This is generally not painful.
Are there risks?
No. Uterine Doppler uses safe sound waves and has no radiation risks to you or your baby.
Can children have this scan?
This scan is for pregnant patients.
Can I have this scan if I am pregnant?
Yes. This scan is performed during pregnancy as a screening tool.
When will I get my results?
The machine calculates the blood flow resistance immediately. A report will be sent to your referring doctor or handed to you within a few hours.
What if the scan finds something?
An abnormal result does not mean you will definitely develop pre-eclampsia. It simply means you have a higher risk. Your obstetrician will review the result and may prescribe preventative medications like low-dose aspirin, or arrange for more frequent blood pressure checks and growth scans.
What are the important limitations?
Ultrasound does not use ionising radiation, but a useful result still depends on the clinical question, the operator, the equipment, patient anatomy, and whether the target can be reached by sound waves. Gas, bone, body habitus, pain, movement, and a limited acoustic window can hide disease. A normal scan does not automatically exclude the suspected condition; persistent or worsening symptoms need clinical reassessment and sometimes repeat ultrasound, CT, MRI, laboratory tests, or another specialist test.
Ultrasound should be used for a medical purpose, with output and examination time kept as low as reasonably achievable—especially in pregnancy and with Doppler. Internal scans and procedures require explanation, consent, privacy, and a chaperone according to patient preference and local policy.
Questions to ask your care team
- What exact question should this ultrasound answer, and could anything important remain unseen?
- Is this a screening, diagnostic, surveillance, or procedure-guidance examination, and will the result change care?
- What preparation is required, and should I continue all medicines unless my own clinician gives different instructions?
- When will I receive the signed report, who will explain it, and what symptoms should prompt urgent assessment rather than waiting?
Sources and further reading
- RadiologyInfo.org: Obstetric ultrasound
- AIUM: Prudent clinical use and safety of diagnostic ultrasound
Conclusion
A uterine artery Doppler scan is a safe, proactive screening test that helps your healthcare team protect both you and your baby during pregnancy. No special preparation is needed, so you can go about your day normally after the scan.