by Dr. Nor Ashikin Mokhtar
Remember in 2005 when Tom Cruise bought an ultrasound machine for his home, so that he could monitor his wife Katie Holmes’ unborn baby?
Medical experts in the US were alarmed and outraged that this could occur. The ultrasound examination is not a game, but a medical procedure that is performed by trained experts as an important part of prenatal checkups.
What exactly do doctors look for in an ultrasound? How will this information help expecting mothers? Are there any risks involved?
What is Ultrasound
Ultrasound is the technology of using high-frequency sound waves to create an image. These sound waves are directed at the foetus using the 'transducer', which is the gadget that is run gently over the stomach. The sound waves are then bounced back to produce a picture on the screen.
This 'picture' tells the proud parents-to-be whether their baby will be a boy or a girl, or whether there is more than one baby!
An ultrasound should routinely be done for all pregnancies during the first trimester. During this ultrasound, the doctor will look for a number of things, such as to confirm whether the pregnancy is in the uterus, the viability of the foetus (is the heart beating?), the number of foetuses and the size of the foetus to look for whether it corresponds to the period of the pregnancy.
The cervix, that is the mouth to the womb, the uterus, as well as the ovaries are also scanned for any abnormalities.
In the second trimester, the ultrasound is performed to look for any anatomic or structural abnormalities - where the placenta is implanted, and how the fluid around the baby looks. If any abnormalities are found, the doctor will continue to evaluate them in the third trimester. The final ultrasound will also be done to monitor the foetus’ growth and size.
The third trimester ultrasound is not done routinely, and only if there is a need to follow up on a significant problem found in the earlier ultrasound such as if the foetus is not growing as expected or there is concern regarding the well-being of the foetus.
An ultrasound can give important information about whether the baby has any abnormalities. Firstly, the obstetrician will look at whether the placenta is normal. For instance, is it implanted too low in the uterus, which might cause bleeding during pregnancy? Or is it implanted in a location that will interfere with a vaginal delivery?
The ultrasound will also show whether any organs, such as the kidneys or brain, are missing or not developing well. Structural abnormalities, such as a hole in the heart, abnormal spine formation and other congenital problems, may also be spotted.
The doctor will also use the ultrasound image to measure the bones and the size of the head, in order to check the growth of the foetus.
The ultrasound is also important for mothers who have problems before or during pregnancy, such as hypertension, diabetes or certain infections. If the mother has a high risk pregnancy, then tests such as chorioinic villous sampling can be done as early as 8 weeks onwards.
Other tests include amniocentesis, placental biopsy and umbilical cord sampling, all of which are used to analyse abnormalities in the baby’s chromosomes. Some of these tests can be invasive and relatively riskier than others, so you should discuss every option with your doctor before making a decision.
Of course, every parent-to-be will hope and pray that the ultrasound does not show any abnormalities in the first place. However, it is important to remember that the ultrasound is not a fool-proof test. It cannot pick up every single detail about the foetus, so there may be abnormalities that cannot be found in an ultrasound, or there may be instances where it is difficult to determine the sex of the baby.
Because an ultrasound uses sound waves, and not radiation, an ultrasound will not harm your unborn baby.
However, it is still unwise to overuse or abuse this technology. You cannot have an ultrasound done whenever you wish just because you feel like 'having a look' at the baby, or you want to see how much it weighs.
The ultrasound has to be used at the right time, for the right reasons. If a mother does not have any risk factors, further ultrasounds – other than the basic one or two – are not necessary.
It is also important that the ultrasound be performed by the appropriate expert - the foetal medicine specialists - when looking for foetal anomalies and in assessing high risk pregnancies so that they know what to look for. An untrained eye looking at the picture could miss some crucial information or problems with the baby.
More info on ULTRASOUND here.