The benefits of 4D ultrasound

Ultrasound is used a lot in gynaecology. 4D ultrasounds are able to show the baby with complete accuracy and in real time, and at any gestational age, giving it an advantage over 3D ultrasound, which only produces a faint imagery as an output. 4D ultrasound, in addition to being in real time (24 images per second), is represented in a sepia colour, so that the face, hands, feet and even the entire bone structure in volume can be seen.

At the moment 4D ultrasound is only used to show prospective parents their baby during pregnancy, and is not used for diagnosis in obstetrics, except for when there may be visible issues with the face and limbs. The best time to perform a 4D ultrasound is between week 26 and week 32, with weeks 27, 28 and 29 being the ideal time to watch videos in detail.

For diagnosis of possible complications, the traditional 2D ultrasound is the best method. The ideal is to make a 4D echo in prenatal diagnosis and then make a 2D echo to evaluate the baby in its entirety: check for a late malformation not observed at 20 weeks; calculate weight and assess if the foetus is too "fat or “thin”; check if placenta is functioning well and there is sufficient amniotic fluid; and check the Doppler flows in the umbilical, cerebral, uterine, and other arteries.

4D ultrasound is a comforting experience for the mother because she has seen her baby in full vision and an expert in prenatal diagnosis has made a complete exploration of her baby.

Does 4D ultrasound present any risks?

People often ask if ultrasounds can harm a baby. The answer is that it is a simple, innocuous technique that does not produce pain. It is, therefore, a safe practice for both the pregnant mother and the baby, since the latter does not receive the theoretical heat produced by the ultrasound. State-of-the-art ultrasound probes are designed to have no microwave effect on the foetus.

The frequency of ultrasound can be variable, from weekly to quarterly. In 80% of cases, routine 2D ultrasound per trimester of pregnancy is sufficient, and there are no reasons to perform more, except for those couples who wish to perform a 4D echo between weeks 26 to 32. In these cases, the social security does not cover it, so they must be done privately.

How is 4D ultrasound performed?

Ultrasound can be performed vaginally or abdominally. Vaginal 4D ultrasound is the favourite method of most sonographers in the first weeks of gestation and to measure the cervix in those cases suspected at being at risk of miscarriage or threat of preterm labour, because it provides a clearer image of the abdominal pathway. The abdominal route is the one most routinely used.