Ultrasound During Pregnancy: Why, When, and How?

Today we are with Dr. Sandhya Dhankhar, and we will be discussing the importance of ultrasound during pregnancy.

Why do we have an ultrasound during pregnancy? Or  Is ultrasound necessary in pregnancy?

Ultrasound gives a window to look at the fetus, and rather it is just the only window through which we can see it.

What does an ultrasound detect? Or अल्ट्रासाउंड में क्या क्या पता चलता है?

Ultrasound tells about the location of the fetus, how many fetuses are there, single, twins. It tells about the growth of the fetus, so there are many abnormalities that can be detected by ultrasound.

Why is it mandatory to have so many ultrasounds during pregnancy?

Many patients asked why so many ultrasounds now and how many times ultrasound is safe during pregnancy. Previously there were not so many ultrasounds done. Nowadays, everybody is cautious to have a good baby or a normal baby and not so many babies are there, everybody wants to have one or two or want a perfect baby, so to detect at every step like the fetus is growing well, or there are any abnormalities whether the fetus is growing so there are types of scanning during pregnancy at different timings. Different types of ultrasound in pregnancy are done to detect the growth and normality of the pregnancy.

Whether the ultrasound is safe or is it harmful?

Ultrasound is completely safe, and it is a myth that it is unsafe for the baby. And an ultrasound can be done on alternate days every week. So it is completely safe in pregnancy.

Which month should a pregnant lady start getting an ultrasound? Or When do you have your first pregnancy scan?

Different ultrasounds are done at different periods of gestation. Like in early pregnancy, we look for the number of fetuses. Where exactly is the pregnancy, whether it is in the uterus or outside the uterus, which we call ectopic pregnancy? 

So we need to locate the pregnancy, where it exactly is, whether it is a viable pregnancy. You can see the heartbeat of the fetus at six weeks, i.e., one and a half months.  And then, we do an ultrasound known as an anti scan in the third month of the pregnancy, around 12 weeks. Different ultrasounds are done at different timings to detect different things.

How many ultrasounds should be done in total?

There should be six ultrasounds in nine months but if there are any problems then you can have more scans. 

What are the important scans that should be done?

Firstly, in early pregnancy, to detect the viability and the number and the location of the pregnancy.  Then anti-scan at  12 weeks and level II scan or anomaly scan at fifth month, around eighteen to twenty weeks. And growth scans around twenty-eight weeks, thirty-two weeks, thirty-six weeks.

These are the main, important scans.

Can we detect all types of abnormalities during the ultrasound?

Usually, structural abnormalities can be detected very easily. However, there are a few things that cannot be detected by ultrasounds. So you have to be cautious in picking up the markers which tell you that this can be an abnormal baby, although it looks normal. 

Nothing can be 100% in medicine, so there is always a sensitivity of each test. Ultrasound also has a sensitivity of approximately 90 to 95%.

Why is a blood test done during pregnancy? Or which blood test is done for pregnancy?

Different blood tests are done during pregnancy. A few blood tests like :

1. Hemoglobin
2. Blood sugar

These are for detecting any abnormalities in the mother itself. During pregnancy, there are a lot of changes in the mother’s body, so viral markers lead to a lot of infections. There are two particular tests. This is one dual test that is done at around 11 weeks or 12 weeks. And second is the quadruplet test, which is done around the fourth month onwards till 20 weeks. Timing is from 16 to 20 weeks, and these two tests are done to detect the abnormalities in the fetus. We take the mother’s blood to detect the abnormalities in the fetus. These are two important things that are done along with ultrasound. 

If done under the specific guidelines under specific parameters, these things got a better sensitivity. So it is better to do it under labs that are fetal medicine certified. Those who know the importance of each and every marker, those who know the importance of each and every measurement. So they take pains to do a scan in a proper way.

Thank you so much!