An ultrasound is a test that uses high-frequency sound waves to show images of the baby, amniotic sac, placenta and uterus. The doctor will use gel that works as a conductor for the sound waves. Those waves are recorded and transformed as images of your baby. It gives you an idea about your baby’s health and wellness.
There are different types of ultrasound:
Transvaginal ultrasound, mainly used during the first stages of pregnancy.
Standard ultrasound used during pregnancy showing the fetal development.
Doppler ultrasound measures how well blood is flowing in your baby’s body.
3D ultrasound gives 3D images of the fetus.
4D ultrasound records the baby’s movements.
Fetal echocardiography ultrasound gives more details of your baby’s heart.
The average number of ultrasound during pregnancy is three:
The First trimester ultrasound is done to confirm pregnancy, heartbeat and to know the gestational age.
The Second trimester ultrasound is done to measure the fetus limbs, confirm that the placenta is healthy, amniotic fluid is normal, and to detect any birth defect and malformation. You may also know the gender of the baby at this stage.
The Third trimester ultrasound identifies the placenta location, quantity of the amniotic fluid, fetal movements, baby's position and expected weight.
Ultrasounds are not harmful and do not have any side effects on you or the baby. Usually the test takes 20mn only and you are required to keep your bladder full especially during early stages of pregnancy. It gives an overall idea of the fetus well being and can detect most possible problems.