Today, most women find it hard to imagine a gynaecological examination or pregnancy monitoring without an ultrasound scan, yet the truth is that this “invention” has only existed since the mid-1950s.

In today’s article, we look at how ultrasound works, what types there are, what it examines, and whether its use poses any risk to mother and baby.

Uses of ultrasound in gynaecology, obstetrics and prenatal medicine

Ultrasound diagnostics can be widely used to assess the health of mother and foetus both before and during pregnancy.

Ultrasound can be used for:

  • Examining the uterus and ovaries, including checking for the presence and development of ovarian follicles to determine ovulation (folliculometry).
  • Confirming pregnancy — with the possibility of detecting it very early.
  • Determining whether the pregnancy is single or multiple.
  • Monitoring the growth and development of the baby in the womb, including all its vital organs and systems.
  • Checking the baby’s heart activity and muscle tone, as well as blood flow in the uterine arteries and other arterial and venous vessels.
  • Screening for congenital defects and anomalies.
  • Assisting with other prenatal tests, such as chorionic villus sampling or amniocentesis.
  • Detecting pregnancy complications, including ectopic pregnancy, molar pregnancy and miscarriage.

In addition to the classic ultrasound scan, the best clinics in Switzerland offer numerous other examinations that provide information about your baby’s health, for example organ screening, nuchal translucency measurement, Doppler sonography or 3D ultrasound.

Monitoring of pregnancy and childbirth in Switzerland is planned week by week.

First trimester (12–14 weeks)

The first-trimester scan between the 12th and 14th week of pregnancy serves to confirm that the pregnancy is progressing normally. In particular, the baby’s heartbeat and body shape are checked. At this point it will also become clear whether a multiple birth can be expected. Based on specific measurements, such as the crown–rump length, the due date is checked and finally determined. The first signs of a developmental abnormality can be recognised. An increased nuchal fold may indicate a chromosomal condition. Then, after consultation with the parents-to-be and only at their request and with their consent, further examinations are arranged.

Second trimester (20–23 weeks)

The second scan is carried out between the 20th and 23rd week of pregnancy.

Several measurements are taken (head and waist circumference, femur length) to assess the baby’s growth and compare them with the values from the first scan. By now the baby is so developed that all organs are formed and have reached a size that allows targeted ultrasound imaging. All vital organs can be shown clearly. This makes it possible, on the one hand, to detect developmental abnormalities directly (for example heart defects, kidney malformations, spina bifida and so on) and, on the other, to identify signs of childhood diseases. If there are signs at this stage that the baby has a condition, further diagnostic and therapeutic steps can be planned according to its severity — including, where necessary, while the baby is still in the womb.

Third trimester (30–32 weeks)

A third scan may be carried out in the 30th–32nd week of pregnancy. The baby’s development (weight), the baby’s position, the position of the placenta and the amount of amniotic fluid are checked again. All the organs have now grown even larger, and in some cases they can be seen more clearly. If any of the examinations reveals an abnormality, further examinations or monitoring methods may be initiated.

Can ultrasound harm the baby?

Ultrasound is a safe and painless examination, with no increased risk of miscarriage or of harming your baby. The sound waves used have a very high frequency, far beyond the range of human hearing; they will cause no harm to you or your baby, and your baby cannot hear them.