A Doppler scan measures the blood flow through the umbilical cord and around different parts of your baby’s body, such as his brain and heart. This helps to show whether he’s getting all the oxygen and nutrients he needs via the placenta.
Doppler ultrasound is used in pregnancy to study blood circulation in the baby, uterus and placenta. Your doctor may recommend a Doppler scan if you need extra care during your pregnancy or your baby is small for dates. The scan can look at whether the placenta is working normally and delivering enough oxygen and nutrients to your baby. Doppler scans should not be used before 24 weeks. But used properly, Doppler scans pose no risk to your baby in the second and third trimesters.