Every pregnant patient undergoes an ultrasound scan. Most of them also have a Doppler ultrasound scan. It is usually part of a routine examination during which the doctor assesses the vascular flows in the baby or in the uterine arteries of the expectant mother.
Doppler ultrasound in pregnancy – Thrombosis
Doppler ultrasound is used to assess vascular flow. It is considered a safe examination during pregnancy. Doctors order a Doppler ultrasound scan if they suspect a venous thrombosis, for example. This allows the flow of the mostly venous lower limbs to be checked. Doppler ultrasound is performed when leg swelling, varicose veins or sudden pain in the lower limbs occur. Similar symptoms may indicate an abnormal flow in the vessels. If thrombosis is diagnosed during pregnancy, anticoagulant treatment with heparins must be administered. Therefore, a doctor should be consulted if symptoms similar to those described above occur.
Doppler ultrasound during pregnancy – blood flow in the baby
Doppler ultrasound is used during pregnancy to assess the vascular flow in the baby. The gynaecologist assesses the flow in the middle cerebral artery, the umbilical artery and the venous line. Abnormal flow values and velocities in the middle cerebral artery can indicate, among other things, anaemia in the baby or centralisation of the circulation. Doppler ultrasound is particularly useful for monitoring the well-being of a foetus suffering from growth restriction, for example.
Doppler ultrasound in pregnancy – first trimester
Doppler ultrasound is also used in the first trimester examination. Among other things, it is used to assess the heart and the number of ventricles, the left ventricular outflow tract or the projection of the vessels coming from the heart. In this way, the doctor can assess the normal structure of the foetal cardiovascular system or detect abnormalities and refer the patient for a detailed echo of the baby’s heart.
In addition, the combined test carried out in the first trimester must assess the flow in the uterine arteries of the pregnant woman. This is because they are one of the elements used to assess the risk of pre-eclampsia in the expectant mother.
However, it is currently not advisable to use Doppler ultrasound in pregnancies under the 10th week. The so-called M-mode technique is then used to “hear” the heartbeat.