ಗರ್ಭಾವಸ್ಥೆಯ ಸ್ಕ್ಯಾನ್ಗಳು
Doppler Scan (Fetal Doppler Ultrasound)
Checks blood flow to your baby through the umbilical cord and brain
ಇದು ಯಾವ ಸ್ಕ್ಯಾನ್?
A Doppler scan is a specialised ultrasound that measures the speed and pattern of blood flow in specific blood vessels — most importantly the umbilical artery (blood flowing from the placenta to the baby), the Middle Cerebral Artery (MCA — blood flow to the baby's brain), and the Ductus Venosus (DV — blood flow through the baby's liver). It uses the Doppler effect: the change in sound wave frequency as blood moves toward or away from the probe. The results are displayed as waveforms on a screen and analysed for resistance and flow patterns.
ಇದನ್ನು ಏಕೆ ಮಾಡುತ್ತಾರೆ?
Doppler is not a routine scan — it is ordered when there is a concern about placental function or fetal wellbeing, typically when the baby has been identified as small (SGA/FGR), when the mother has gestational diabetes or hypertension, when there are reduced fetal movements, or when the previous growth scan raised a concern. The key measurement is the Umbilical Artery Pulsatility Index (PI) — high resistance in the UA indicates the placenta is not working well. The Cerebroplacental Ratio (CPR = MCA PI / UA PI) detects 'brain-sparing': when a compromised baby diverts blood preferentially to the brain.
ಏನನ್ನು ನಿರೀಕ್ಷಿಸಬಹುದು
A Doppler scan is usually done as part of or alongside a growth scan. It involves the same abdominal probe. The sonographer places the cursor over specific vessels and the machine automatically calculates the flow indices. It adds about 15–20 minutes to the scan. No special preparation is needed. The scan is completely safe.
ಸಾಮಾನ್ಯ ಫಲಿತಾಂಶಗಳು
- ✓ Umbilical artery (UA): normal pulsatility index (PI) for gestational age — positive forward flow throughout the cardiac cycle
- ✓ Cerebroplacental ratio (CPR) > 1.0 — normal (placenta not restricting flow)
- ✓ Middle cerebral artery (MCA): normal PI for gestation
- ✓ Ductus venosus (DV): positive a-wave (normal waveform)
- ✓ End-diastolic flow present in the umbilical artery
ಯಾವಾಗ ಕಳವಳ ಪಡಬೇಕು
- Absent end-diastolic flow (AEDF) in umbilical artery — severe placental insufficiency; urgent review needed
- Reversed end-diastolic flow (REDF) in umbilical artery — critical; high risk of stillbirth; often prompts delivery
- CPR < 1.0 — brain-sparing detected; indicates the baby is diverting blood to protect the brain; close monitoring needed
- Abnormal ductus venosus waveform (absent or reversed a-wave) — severe fetal compromise; delivery planning required
- Raised MCA PI with low UA PI — may indicate anaemia in the baby
ಪದೇ ಪದೇ ಕೇಳಲಾಗುವ ಪ್ರಶ್ನೆಗಳು
What is the difference between a regular growth scan and a Doppler scan?
A regular growth scan measures the baby's size and amniotic fluid using standard B-mode ultrasound. A Doppler scan adds assessment of blood flow patterns in specific vessels. They are often done together: the sonographer measures the baby first, then adds the Doppler assessment of umbilical and brain blood flow. Doppler requires specific equipment and training.
Why has my doctor ordered a Doppler scan?
Common reasons include: baby measuring small on growth scan, gestational diabetes with poor control, high blood pressure or pre-eclampsia, reduced fetal movements, history of previous pregnancy with growth restriction, or twin pregnancy. Doppler helps your doctor decide whether the baby is coping well in the womb and whether delivery should be expedited.
What happens if my Doppler results are abnormal?
The response depends on how abnormal and at what gestation. Mildly abnormal Dopplers (raised PI) may mean more frequent monitoring. Absent or reversed end-diastolic flow — especially late in pregnancy — often means the baby needs to be delivered. Your doctor will explain the findings and the plan. Doppler results are never interpreted in isolation — they are combined with growth measurements, liquor volume, CTG, and clinical assessment.
Is a fetal Doppler scan the same as the home Doppler device?
No. Home Doppler devices are handheld devices that let you listen to the baby's heartbeat. They cannot measure blood flow indices. The Doppler scan done at a hospital uses specialised diagnostic ultrasound equipment to calculate PI and RI values in specific vessels — a completely different and much more complex assessment.
If the Doppler is normal, does it mean my baby is definitely safe?
A normal Doppler is very reassuring and indicates that placental blood flow is adequate at the time of the scan. However, Dopplers are repeated at intervals because the situation can change, especially in pregnancies with growth restriction or hypertension. Your doctor will advise how frequently to repeat the scan based on your condition.