The main aim of Baby Position Scan (or Presentation Scan) is to diagnose breech position or other abnormalities in the baby's position
Normally, a few weeks prior to birth, the baby will move into a delivery position where the head is positioned close to the birthing canal. However, about 3-4% of babies remain in a breech position. This is where the baby’s buttocks are positioned closest to the birthing canal, resembling a sitting position. Delivering a baby in breech position can be dangerous, but in roughly 50% of cases the position can be corrected by external cephalic version (ECV), which is a manual process performed by an obstetrician to turn the baby upside down in the womb allowing a head-first delivery. Alternatively, a caesarean section may be the safest option.
In most cases, an experienced midwife can recognise a breech position through an external manual examination of the baby, which is done by feeling for the baby’s orientation through the mother’s lower tummy. However, in some cases, the breech position remains unnoticed until active labour and/or rupture of membranes.
Thus, the main aim of our Baby Position Scan is to recognise an undiagnosed breech position.
Some of the other things we also look out for include:
- Monitoring the growth of the baby,
- Baby’s well-being (such as movements, amniotic fluid, and fetal Dopplers),
- The placenta.
What is the best time for a Baby Position Scan?
The best time for this scan is at 36 weeks of pregnancy.
By this time, if the baby’s head is not near the birthing canal, there is still time to discuss external cephalic version (ECV) or other delivery plans with your doctor or midwife.
Can we exclude any fetal anomalies using the Baby Position Scan?
The Baby Position Scan is less effective at detecting anomalies for the following reasons:
- The relatively big dimensions of the baby and the reduced amount of amniotic fluid by this stage of pregnancy severely hinder the resolution of the images and make it virtually impossible to perform a systematic examination of the baby,
- In the unfortunate event that a serious anomaly is detected, it would be too late to perform a full diagnostic work-up and proper counselling of the parents.
If you are worried about late manifesting fetal anomalies, which can develop after the anomaly scan performed at 18-20 weeks, we strongly recommend getting our Baby Development Scan at 32-34 weeks.
Is it possible to perform a 4D scan during Baby Position Scan?
Usually performing a 4D scan during a Baby Position scan is ineffective because:
- The resolution of the image is severely affected by the naturally reduced amount of amniotic fluid by this stage of pregnancy,
- By this stage the majority of babies are facing their mother’s backs in preparation for delivery, meaning we would not be able to produce a useful scan.