Predict pre‑eclampsia and IUGR
Elevated uterine artery PI and/or diastolic notching at 20‑24 weeks are strongly associated with the later development of pre‑eclampsia and fetal growth restriction – with odds ratios of 5‑10 in high‑risk women.
The uterine arteries are the main blood vessels supplying the uterus and placenta. Doppler assessment of the uterine arteries evaluates the resistance to blood flow – a key indicator of placental perfusion. Abnormal uterine artery Doppler findings in the second trimester are strongly associated with the development of pre‑eclampsia, fetal growth restriction (IUGR), and placental abruption.
Uterine artery Doppler is typically performed between 20 and 24 weeks, although it can be done earlier (e.g., in the first trimester in high‑risk populations). It has a high negative predictive value – a normal scan provides strong reassurance that the pregnancy is unlikely to be affected by these complications. An abnormal scan allows for increased surveillance, prophylactic aspirin, and timely intervention.
At Amytri, our uterine artery Doppler examinations are performed by a consultant radiologist with advanced training in fetal medicine. We use high‑resolution ultrasound and colour Doppler to visualise the uterine arteries, obtain reliable waveforms, and identify any diastolic notching – a hallmark of increased resistance. Our reports are integrated with other risk factors to guide your obstetrician in tailoring your pregnancy care.
Uterine artery Doppler is a window into the placenta's future – identifying women at risk before clinical signs appear, enabling prevention and early intervention.
Elevated uterine artery PI and/or diastolic notching at 20‑24 weeks are strongly associated with the later development of pre‑eclampsia and fetal growth restriction – with odds ratios of 5‑10 in high‑risk women.
Women with abnormal uterine artery Doppler are candidates for low‑dose aspirin prophylaxis, which reduces the risk of pre‑eclampsia by about 60‑80% when started early and taken consistently.
If uterine artery Doppler is abnormal, we can plan more frequent blood pressure checks, urine protein testing, and fetal growth scans – enabling early detection and treatment of complications.
We evaluate both uterine arteries, using a standardised protocol to ensure reliable and reproducible measurements.
We measure the PI in each uterine artery. A PI above the 95th percentile for gestational age indicates increased resistance and is a marker of impaired placentation.
RI is another measure of resistance. An elevated RI also suggests increased resistance, though PI is more commonly used in clinical practice for uterine artery assessment.
We assess the presence or absence of a diastolic notch – a sharp downward deflection in the waveform. Bilateral notching (present in both arteries) is a strong predictor of pre‑eclampsia and IUGR, especially when combined with elevated PI.
We note whether abnormalities are present in one or both uterine arteries. Bilateral abnormalities carry a higher risk than unilateral.
We calculate the mean of the left and right uterine artery PIs – this provides a single, more stable measure that is often used in risk prediction algorithms.
We combine uterine artery Doppler findings with maternal risk factors (age, BMI, blood pressure, prior pre‑eclampsia) and biomarkers (PAPP‑A, PlGF, sFlt‑1) to provide a comprehensive risk profile.
Your obstetrician refers you for uterine artery Doppler – often as part of routine second‑trimester screening (20‑24 weeks), or earlier if you have risk factors for pre‑eclampsia or IUGR.
We identify both uterine arteries using colour Doppler, where they cross the external iliac arteries. We obtain spectral waveforms, measure PI, and check for notching.
We compare PI values to gestational age‑specific reference ranges. A mean PI ≤95th percentile with no notching is normal. Elevated PI or bilateral notching indicates increased risk.
We provide a detailed Doppler report and discuss the findings with you and your obstetrician. Depending on the result, we may recommend aspirin, serial BP monitoring, growth scans, or referral to a specialist.
It is often offered as a routine screening test in the second trimester, but is especially important for women with risk factors.
Nulliparity is a risk factor for pre‑eclampsia – uterine artery Doppler screening is recommended in many guidelines.
If you have a history of placental complications, uterine artery Doppler can identify recurrence risk and guide prophylaxis.
These conditions increase the risk of pre‑eclampsia and IUGR – uterine artery Doppler helps stratify risk.
Twin and triplet pregnancies are at higher risk of pre‑eclampsia – uterine artery Doppler is recommended for risk assessment.
Low PAPP‑A or PlGF in the first trimester is associated with placental dysfunction – uterine artery Doppler complements this risk assessment.
Advanced maternal age increases the risk of pre‑eclampsia and IUGR – screening is recommended.
Uterine artery Doppler requires standardised technique and careful interpretation. Our consultant radiologist has extensive experience in maternal‑fetal Doppler, ensuring accurate and reproducible measurements that guide your clinical care.
Uterine artery Doppler is a simple but important test – having your partner with you provides support and shared understanding.
We encourage partners to attend the Doppler examination. We explain the waveforms and what they indicate, and answer any questions. If the results are abnormal, we discuss them sensitively and provide a clear plan for management – including aspirin, monitoring, and delivery planning.
It is a specialised ultrasound that measures blood flow in the uterine arteries, which supply blood to the uterus and placenta. It is used to predict the risk of pre‑eclampsia and fetal growth restriction.
Yes. It uses standard diagnostic ultrasound with no known harmful effects. The thermal index is kept within safe limits, and it is widely used in obstetric care.
Normal results (low PI, no notching) indicate good placental perfusion and a low risk of pre‑eclampsia/IUGR. Abnormal results (elevated PI or bilateral notching) indicate impaired perfusion – increasing the risk of these complications and prompting preventive measures.
The optimal timing is 20‑24 weeks for second‑trimester screening. In some high‑risk populations, it may be performed in the first trimester (11‑14 weeks) as part of an integrated risk assessment.
Yes, typically a referral from your obstetrician is required. They will indicate the indication and whether additional tests (e.g., biomarkers) are needed.
We will discuss the findings with you and your obstetrician. Recommendations may include low‑dose aspirin prophylaxis, more frequent blood pressure monitoring, serial fetal growth scans, and, in some cases, referral to a specialist in maternal‑fetal medicine.
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