Ultrasound In Pregnancy – It is a must today …
Is Ultrasound safe in pregnancy ?
Ultrasound is not just safe but also essential for proper antenatal monitoring. Ultrasound doesnot use any harmful radiation. The strength of the ultrasound beam used in routine Ultrasound B scan has not shown any harmful effects to the fetus (baby) in any trimester.
When and how many times should an ultrasound be done ?
In my opinion atleast three scans are essential in pregnancy. The first being performed around two weeks after the missed period i.e. at 6 weeks. The purpose of this scan is to confirm presence of intrauterine pregnancy and the presence of cardiac activity. Also uterine pathology such as fibroids and adnexal lesions can be detected at this stage. The second scan should be performed at 16-18 weeks to rule out congenital fetal anomalies and asses fetal growth. The third essential scan should be performed at around 32 weeks. The purpose of this scan is to evaluate fetal growth.
But I had to undergo more than three scans in pregnancy …..
Additional scans maybe required if clinically indicated. For example if the first scan does not confirm presence of cardiac activity an additional scan is required at a later date. This maybe because of discrepancy in dates or an abnormal pregnancy. Also bleeding per vaginum anytime during pregnancy may warrant an additional scan. A scan maybe done after 37 weeks if cord around neck is suspected. At all stages the attending obstetrician is the best person to decide whether a scan is needed or not.
Is a transvaginal ultrasound scan essential ?
Transvaginal ultrasound has a higher resolution so it gives a better picture. It may be essential in some cases in first trimester where the trans-abdominal scan is inconclusive. This can occur in obese patients or in cases where the uterus is retroverted (tilted backwards).
Is a transvaginal ultrasound scan harmful /painful ?
No. Transvaginal ultrasound does cause some discomfort but is not painful, nor is it harmful to the patient or the fetus. In fact it allows earlier confirmation of pregnancy than a trans-abdominal scan.
Should an X-ray or CT Scan be done in pregnancy ?
It should be avoided as far as possible as both can be harmful to the fetus especially in the first trimester. If at all an imaging study is required consider doing an MRI instead if possible.
What is 3D / 4D Ultrasound ?
The routine scan is a 2D scan. With technological advancement it is now possible to use the 2D image data to produce a 3D ( three dimensional) picture of the fetus. This is more like a photograph of the fetus. 3D images in real time gives us a 4D scan. This is more like a video of the fetus. Apart from cosmetic value these techniques allow better evaluation of certain anomalies. However, they are not essential in all cases.
Note : Pre-Natal Sex determination by ultrasound is illegal in India.