3D Ultrasound in Pregnancy – Dr. Bhagyam Nagarajan, D.N.B, D.M.R.D

  1. IS 4 D ULTRASOUND BETTER THAN 3D ULTRASOUND?

In pregnancy, 4D and 3D ultrasound essentially mean the same thing which is a 3D image of the baby. 4D also includes a 4th dimension (time) so you can see the 3 D images of the baby moving in real time– it is a live video showing the baby as she is moving inside you.

When you are sent for a pregnancy 3D Scan -the Radiologist will always do both a 3D and a 4D scan irrespective of whether the requisition is for a 3D or 4D -and you will be able to see both 3D (still) and 4D (moving) images of your baby.  Sometimes you may be able to watch your baby smile or suck her thumb.

  1. WHAT HAPPENS DURING A 3 D SCAN-DO I NEED TO PREPARE DIFFERENTLY FOR IT? HOW LONG DOES IT LAST?

Preparation for a 3D scan is the same as for a routine scan –

Eating before the scan always helps as babies are generally more active after a meal and so better images may be obtained. A 3D Scan may take anywhere between 10-30 minutes. Sometimes if parts of the baby are not well seen due to the baby’s position. It is completely normal for you to be recalled for the same exam on the same or later date.

  1. IS A 3D SCAN AT ALL USEFUL OR IS IT JUST A MARKETING GIMMICK?

3D scan is useful to look for certain abnormalities in the baby. These include cleft lip, cleft palate, spine abnormalities and club foot. while a few of these may be picked up on a 2D ultrasound, many of these are diagnosed with more confidence and detail on a 3D scan. 3D scanning is also useful to look at the fetal heart in detail. A 3D scan is optional and your doctor will decide if it is required or not. Many obstetricians request a 3 D scan in the mid or late second trimester to make sure the pregnancy is proceeding smoothly.

  1. WHEN IS THE BEST TIME TO DO A 3D SCAN?

Any time before the 30th week is fine. The ideal time to do a general 3D Scan to see the baby well is between 24-30 weeks. During this time of the pregnancy, there is enough fluid around the baby plus the baby is also quite active and changes position often so you can see parts of the baby well.

Some doctors may request a 3D scan along with an anomaly scan earlier in the pregnancy sometimes between 16 to 24 weeks. This is to rule out any abnormalities in the baby.  Though the images may not be as good after 30 weeks, in most cases a good 3D scan is difficult because of the baby’s position and because the fluid decreases.