Second-Trimester Ultrasound: What You Need to Know

Once you get to your second trimester of pregnancy, you’ll likely be over most of your morning sickness and will be feeling a lot better. Your checkups will change a little and will include an ultrasound at some point, which can also be exciting. Having an ultrasound during pregnancy is common and can tell both the doctor and the mother that things are progressing normally. Before that first ultrasound, however, there are some things that you should know.

Preparing for the Ultrasound

The second trimester covers week 13 to week 28. Second-trimester ultrasounds are usually conducted in weeks 18 to 20, although it depends on the individual circumstances of the pregnancy. Many women have an ultrasound to confirm the pregnancy in the first trimester, and the second-trimester ultrasound is usually done to test for fetal abnormalities.

Keep in mind that this second-trimester scan is not able to diagnose everything because just like other medical tests, it has its limitations. In the second trimester, ultrasounds are usually used to check for things such as the condition of the placenta, fetal anatomy, and how much amniotic fluid there is. While it can tell if there’s extra fluid on the brain, called hydrocephalus, even small heart defects may be hard to find.

As a general rule, you do not need to prepare for an ultrasound. Your doctor may, however, ask you to drink a lot of water beforehand so the bladder is full, making it easier for them to view what’s on the screen. Ultrasounds are not uncomfortable or painful; in fact, they are usually enjoyable events. Even though the technician is looking for specific things, you can just relax and enjoy looking at pictures of your baby.

Is an Ultrasound Safe?

While all medical procedures come with some risks, a fetal ultrasound conducted by a licensed sonogram technician is extremely safe. Unlike X-rays, ultrasounds do not use radiation so the procedure is a lot safer than most people realize. Nevertheless, if you have any questions or concerns about the procedure you should consult with your doctor. Ultrasounds have been used in pregnant women for decades so they’ve been around for a while.

To be sure, ultrasounds have come a long way since their younger days and now include both 3D and even 4D capability. The pictures are often so clear that many people feel like they’re looking at the real thing. These days, you can easily get photographs of the images on the screen and many doctors are now doing that even for non-medical reasons. While organizations such as the March of Dimes discourage that, many parents and doctors are agreeing to it anyway.

Things to Know About Ultrasounds

The more you know about ultrasounds, the better you’ll feel about having one done. It’s best to ask your doctor questions beforehand so you can make an informed decision, and keep in mind that if the ultrasound is done for medical reasons, insurance will usually pay for it. The procedure itself is painless, although you may feel extra full if you’re asked to drink a lot of water beforehand. There may also be some slight pressure if the tech has to press down on your belly.

In general, ultrasounds take around 30 minutes to complete, although it might take slightly longer. The ultrasound technicians are well-trained and know exactly what they’re looking for, and they never take long to complete the procedure. Once the ultrasound is complete, the doctor will go over the results with you and answer any questions you may have at that point.

In your second trimester, it may be suggested that you have some additional testing done, and this might include:

• Triple screen test. This is a blood test that tests for three things: A hormone produced by the baby called AFP, a type of estrogen called estriol, and a hormone produced by the placenta called hCG.
• This is considered an invasive procedure but gives you reliable information on the child’s DNA. A small sample of the amniotic fluid is taken and the baby’s DNA is analyzed to check for any abnormalities.
• One-hour glucose test. This test is to check for gestational diabetes, which is a type of diabetes that some women get while pregnant. Usually, the diabetes goes away after you give birth.
• Cell-free fetal DNA test. This is a relatively new test that checks for chromosomal disorders. It is a screening and not a diagnostic test, but it is a good place to start especially for women over the age of 35.

Conclusion

The ultrasound you get during the second trimester of pregnancy is nothing to fear or panic over because it is painless. It usually takes around 30 minutes to complete and is mostly used to check the amniotic fluid, placenta, and fetal anatomy. There is no preparation required for an ultrasound and it makes a very good screening tool.