Your appointments: 3rd ultrasound: what it reveals

This is your last "virtual" meeting with your future baby before the big meeting. This is an opportunity to make sure your growth continues normally, but also to prepare for delivery depending on your baby's position or weight.

3rd echo, the details

Called "biometric and morphological" ultrasound, it is performed between 32nd and 34th weeks of amenorrhea (counting from the first day of the last period), the 30th and 32nd week of your pregnancy.

At this stage of pregnancy, your future baby is already too big for the sonographer to see in its entirety. He will stop on the skull and femurs to take his measurements.

What is this 3rd echo for?

By measuring the abdominal perimeter and the diameter of the head, the practitioner will make sure that your baby's growth continues normally.

This third echo also allows the search for abnormalities of certain organs that develop later (urinary and digestive tract, heart, brain and spinal cord). The sonographer verifies, for example, that communications between the heart and the atria are normal or that the kidneys are functioning properly.

To detect large babies (more than 4 kg at birth) and smaller ones (less than 2.7 kg).

The sonographer also makes sure that your baby is moving well, that he swallows normally, which also means that he is breathing well.

During this ultrasound, the doctor checks the volume of the amniotic fluid (necessary for the fetal well-being), he notes the type of presentation (full seat or not, for example) and the localization of the placenta which could lead the team doctor to opt for a caesarean section.

Marie Auffret-Pericone with Dr. Ghada Hatem gynecologist-obstetrician, and Dr. Luc Gourand gynecologist-obstetrician and Raymond Gombergh, sonographer.

* Week of amenorrhea: counting from the first day of the last period.

What progress has your baby made this quarter? Click here.

All our ultrasound articles.