St. Luke’s Maternal Fetal Medicine

Ultrasound

We know that having an ultrasound is an exciting part of a pregnancy. Because we want your ultrasound to be a pleasant experience, we have prepared this brochure to answer common questions about second trimester ultrasound. If you have further questions, please talk to your health care provider or contact our office.

What is the purpose of a second trimester ultrasound?
Most babies are born healthy, but about 3% of babies are born with birth defects. No test can detect all birth defects, but a thorough ultrasound in the second trimester can identify several different kinds of birth defects, including many (but not all) birth defects of the heart, digestive system, brain and spinal cord.

Ultrasound can also tell if the fetus is growing normally, if the placenta is in the correct position and if there is the right amount of amniotic fluid.

Most people having a second trimester ultrasound will get the good news that, as far as we can tell, the fetus is growing and developing normally.

What happens if a birth defect is detected on ultrasound?
Occasionally, the ultrasound detects a birth defect. If this happens, our staff will answer questions, and in many cases give you written information on the condition. We will discuss this information with your health care provider and together we will plan appropriate follow up.

Are the results of the ultrasound always straightforward?
No. As the quality of ultrasound improves, we see the fetus in more detail than ever before. We are now frequently able to see relatively minor differences in the fetus. We call these differences “soft findings.” Examples of soft findings are bright spots in the heart or intestines, extra fluid in the brain or kidneys or bones that are shorter than average. Soft findings are not birth defects. Most babies with these findings are totally healthy and normal. But research tells us that babies with these soft findings are slightly more likely to have birth defects or genetic conditions, such as Down syndrome or cystic fibrosis. When we see a soft finding, we look for other evidence that the baby has a birth defect. This may mean doing more ultrasounds, testing the mother’s blood or reviewing family history information. Often this additional information reassures everyone that a serious birth defect is unlikely. If the additional information is not reassuring, then the family may be offered further testing such as amniocentesis.

Does an ultrasound ever need to be repeated?
Yes. Sometimes we will not be able to see everything that we need to see for a complete exam. If this happens, we will make arrangements to complete the exam later (either that day or on another day).

How accurate is the ultrasound for determining the fetus’ sex?
How accurate the ultrasound is for determining sex depends on the age and position of the fetus. With good views, ultrasound is correct
80-90% of the time.

What should I do to prepare for my ultrasound?
You will probably be more comfortable wearing a two piece outfit. Although your bladder does not have to be full, it may be helpful if you do not empty your bladder for about half an hour before your appointment.

Otherwise you do not have to do anything different before or after your appointment.

How long should I expect my appointment to take?
Appointments usually take 30 to 60 minutes.

Can my family come with me to my appointment?
A few family members or friends are welcome. We know how exciting the ultrasound appoint-ment can be and we want you to be able to share the experience with your loved ones. But in order to give you the most accurate ultrasound possible, the person performing the ultrasound needs to be able to concentrate. So we may ask you to limit the number of people you bring into the ultrasound room, minimize conversation, and avoid other distractions. Because of the length of the appointment, young children often become restless and so we encourage you to make other arrangements for their care.

Can I have pictures of the ultrasound?
We will provide you with “snapshots” of the fetus from the ultrasound. However, we are not able to videotape ultrasound exams.

Who will be performing my ultrasound?
A physician with specialty training in fetal medicine or an ARDMS certified technologist will perform the ultrasound. If the ultrasound is performed by a certified technologist, a physician also reviews the results.

Will someone talk to me about the results of my ultrasound during my appointment?
Yes, basic information will be provided to you during the ultrasound. In addition, you will have a chance to speak with one of the physicians about your ultrasound at the end of the appointment. Copies of the report from your ultrasound will be sent to your health care provider.

What if I still have questions?
If you have more questions about this test, please discuss them with your health care provider. You may also contact us at
St. Luke’s Maternal Fetal Medicine
333 N. First Street, Suite 150
Boise, Idaho 83702
phone: (208) 381-3088