Ultrasounds During Pregnancy: Are They Dangerous?

Ultrasounds allow us to know the fetus's state during pregnancy. But many mothers wonder if ultrasounds can be dangerous for our developing babies.
Ultrasounds During Pregnancy: Are They Dangerous?

Last update: 03 September, 2018

Every pregnant woman yearns to know how her baby is doing, and ultrasounds are necessary to find that out. They allow us to observe the condition the fetus is in and discover any possible anomalies. However, there are some who claim that ultrasounds during pregnancy are dangerous for the unborn baby.

Given these doubts, it’s always good for expectant women to speak with their doctors and ask them to explain the real implication of ultrasounds.

What are ultrasounds and what are they for?

Ultrasounds consist of images created by waves that are transmitted from the abdomen or through the vagina. These waves bounce off the uterus and the placenta in order to produce the image.

Ultrasounds can last between 15 and 20 minutes. They are used to confirm that the baby is alive and also measure the amount of amniotic liquid present. They are also useful in detecting multiple births and checking for any alterations in the umbilical cord .

These images provide details regarding fetal growth and weight, the position of the uterus, and placenta previa. But what’s most important is that they help to detect any possible problems that can lead to premature birth.

Ultrasounds During Pregnancy: Are They Dangerous?

Why do some say that ultrasounds during pregnancy are dangerous?

There’s a myth that claims that it’s dangerous to have ultrasounds during pregnancy. Those who make this claim state that the functioning of the ultrasound waves can increase tissue temperatures.

However, this technique is harmless and very simple. It presents no danger at all to the fetus, nor to the mother, given that they don’t use ionizing radiations, as do X-rays. In fact, ultrasound images reveal no alterations or sudden movements of the fetus.

Pregnant women should not get carried away, however, but rather only turn to this study as recommended by their doctors .

How many ultrasounds do doctors recommend?

Although many say that ultrasounds are dangerous, it’s completely normal for doctors to order ultrasounds during pregnancy. They present no risk whatsoever for pregnant women and their babies.

Normally, doctors recommend 3 ultrasounds – 1 each trimester. The first usually takes place between weeks 11 and 14, the second between weeks 18 and 22, and the last between weeks 32 and 36.

In the case of high risk pregnancies, given the risk of miscarriage, hypertension, diabetes or other complications, doctors may recommend additional ultrasounds. In some cases, doctors may even recommend ultrasounds up to every other week.

Should women have ultrasounds done with a full bladder?

The answer depends on whether or not the mother is going to have an abdominal ultrasound during the first weeks of gestation. In this case, doctors may recommend drinking several glasses of water beforehand to obtain better images.

However, in the case of a transvaginal ultrasound, drinking water is not necessary. After 12 weeks of gestation, drinking water for abdominal ultrasounds is also unnecessary because there is sufficient amniotic liquid to produce decent images.

Types of ultrasounds during pregnancy

There are various types of ultrasounds that allow parents and medical professionals to visualize the developing fetus.

2D ultrasounds

As mentioned above, pregnancies usually involve three ultrasounds:

  • Weeks 11-14. The first ultrasound provides information about the number of fetuses and how far along the pregnancy is. It also detects possible early anomalies, as well as the existence of fibroids and cysts in the mother.
  • Weeks 18-20. Besides revealing the baby’s position and measurements, ultrasounds at this point can verify the baby’s anatomy. Doctors can observe the baby’s head, spinal column, heart and extremities.
  • Weeks 32-36. During the third trimester, ultrasounds once again show the baby’s position and also measure the amount of amniotic liquid present. Furthermore, they can detect anomalies that show up later, such as renal obstructions and hydrocephalus.

3D ultrasounds

These images allow you to see your child’s face, body and internal structures more precisely. They also help confirm any anomalies previously detected during a 2D ultrasound.

Ultrasounds During Pregnancy: Are They Dangerous?

4D ultrasounds

This advanced technology detects skin problems and malformations like cleft lip. These ultrasounds also display the baby’s movements in real time and reveal the baby’s face in clear detail. This means parents can have a clear idea of their baby’s physical features.

In conclusion, you can rest assured that the claim that ultrasounds during pregnancy are dangerous is a myth. If you’re pregnant, don’t be afraid to have all the ultrasounds that your doctor recommends.


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This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.