FAQ – Ultrasound in pregnancy

Should I come to the examination with a full or an empty bladder?

In general it is not necessary to come with an empty bladder to the ultrasound examinations during pregnancy, because the urinary bladder’s content does not affect the examination. However, the ultrasound examination during the 12th – 13th week in the first trimester forms an exception to this rule. In this case the most ideal situation in most cases is to have a half-full bladder. How well the ultrasound exam allows the doctor to see depends on numerous factors though, such as the form of the uterus, the position of the placenta and the fetus, possibly existing uterine fibroids, abdominal wall thickness, potential scars on the abdominal wall due to previous surgery, etc. Thus, sometimes it becomes clear only during the examination, if a full or empty bladder provides a better view. Considering the fact that it is much faster to empty the bladder than to fill it up, we recommend you to come to the examination with a half-full baldder.

When can the gender of the fetus be established?

The earliest point in pregnancy when the fetus’ gender can be established with a relatively high certainty is the 15th – 16th week. Sometimes definite signs can be seen during the first semester ultrasound examination, but in such cases it happens very often that reality differs from what it looked like on the ultrasound picture…

Can ultrasounds harm the baby?

According to our current knowledge the answer is a definite NO. There are numerous international studies that focused on this question, but none of them proved that ultrasound had any negative effect on the developing fetus, even in the case of examinations lasting several hours and done every day.

Can the fetus hear the ultrasound?

The commonly stated range of human hearing is 20 Hz to 20 kHz, hence fetuses can also only hear sounds within this range. The ultrasound machine emits sounds between 3 and 7 MHz, having a frequency that is about thousand times higher than what humans can hear. The fetus can thus not hear it either.

Does the pressure exerted on the abdominal wall during examination disturb the fetus?

The fetus is floating in amniotic fluid, and fluids cannot be pressed, therefore no uncomfortable physical pressure is exerted on the fetus.

Can the first trimester combined examination exclude the Down syndrome and other chromosome disorders?

NO, it cannot. The result of this examination only proves a low risk of the occurrence of these diseases. Chromosome abnormalities can only be proved or excluded by a chromosome / genetic test, such as the amniotic fluid analysis or the chorionic villus sampling. Practically, similarly certain test results can be attained for some disorders by doing non-invasive pre-natal testing, which however do not bear any risks of miscarriage.

If the genetic ultrasound does not show any abnormalities, can you say establish that the fetus is definitely healthy?

NO. Unfortunately there are some disorders, which cannot be detected during an ultrasound examination, nor now, nor in the future. In general one can say that more than 90% of serious disorders can be screened during the development of the fetus inside the uterus, but this can differ with regard to each respective organ.