Obstetrical Scans
First Trimester Down Syndrome Screening
This is an ultrasound examination performed between 11 and 14 week’s gestation at
Carnegie Imaging. A measurement of the clear space in the tissue at the back of the baby’s neck is obtained. The presence or absence of the fetal nasal bone is also documented (absent nasal bone may be associated with an increased risk for chromosomal abnormalities). These results are combined with your age and a special blood test to determine if your
pregnancy is at increased risk for certain chromosomal abnormalities such as Down syndrome. This ultrasound can also detect some (not all) birth defects such as whether or not your baby is at an increased risk for heart abnormalities.
For more information refer to the links below:
Second Trimester Scans
Initial Anatomy: This ultrasound is most often performed between 14 and 16 weeks. Your baby’s anatomy is evaluated for possible birth defects. It is important to note that all birth defects cannot be identified while you are pregnant.
Follow-Up Anatomy: This ultrasound is most often performed between 20 and 22 weeks. Your baby’s anatomy is re-evaluated for possible birth defects due to the fact that some features of your baby’s anatomy can be better visualized at this point. Likewise, parts of the baby are still developing. It is important to note that all birth defects cannot be identified while you are pregnant.
Viability/Dating Scans
This is an ultrasound examination which is most often performed in the first trimester (prior to 14 weeks gestation). It determines if the pregnancy is growing properly within your uterus. It also checks to make sure your ovaries are healthy. A first trimester Viability/Dating ultrasound is the best time to establish your due date.
Growth Scans
A
growth ultrasound is performed to determine an estimated weight for your baby. This exam may be ordered if the doctor feels that your baby may be larger or smaller than expected or if you have a medical condition necessitating that the doctor keep track of the baby’s weight. It is important to note that this weight is an “estimate” and actual birth weight and estimated fetal weight can differ. For more information, view our
Growth Scan Page.
Biophysical Profiles (BPP)
This non-invasive and safe ultrasound examination is used to assess the health of your baby. Movement, tone, breathing efforts, and
amniotic fluid volume are checked to help determine how well your baby is doing in your uterus. The goal of this test is to prevent loss of pregnancy and detect a low oxygen supply early enough so that the baby can be delivered safely. This test may be obtained if you aren’t feeling your baby move as often as you did previously, if you or the baby has a medical condition necessitating such evaluation, you are older than 35 years old, you have a history of pregnancy complications or loss, or you have a certain medical condition such as lupus, diabetes, or high blood pressure. For more information, read:
Biophysical Profiles (BPP)
Cervical Length Studies
A cervical length ultrasound measures the length of your cervix. During pregnancy, the length of the cervix can shorten too quickly, increasing the risk of preterm labor. This may heighten your baby’s chances of developing health issues. You made need this test if you are having symptoms of preterm labor such as contractions or pressure or if you have a previous history of preterm labor and or preterm delivery.
Doppler Studies
Doppler studies are a special non-invasive ultrasound of the maternal, placental, or fetal vessels. During this test, sound waves are used to detect the movement of blood in vessels. The results are then shown on a computer screen in lines known as waveforms. It is utilized to determine if your pregnancy is at risk for problems or to determine the health of your baby in utero. These tests are only obtained if you or the baby has a condition necessitating them, such as
intrauterine growth restriction (IUGR), or when the baby is smaller than normal for the number of weeks of pregnancy.
Placental Check
Ultrasound may be used to identify the location of your placenta. This test is often performed at your 18-week ultrasound. Your doctor may order this test if you have a history of vaginal bleeding or if your placenta looks like it may be near your cervix.
Multiple Gestation Imaging
For the most part, the ultrasound examinations for patients with twins, triplets, and high-order multiples are the same as for patients who are pregnant with one baby. Nonetheless, patients with multiples often undergo more ultrasounds due to the fact that they may need to be monitored for signs and symptoms of
preterm labor and delivery as well as growth discordance among twins.
Fetal Echo
This is a special ultrasound of the baby’s heart that can be performed any time after 17-18 weeks gestation. This test may be needed if you have a family history of congenital heart defects or if it is difficult to visualize all of the parts of the heart at the time of routine anatomical screening. This test can take anywhere from 30 minutes to 2 hours to complete, depending on the findings.
3D Ultrasound
3D ultrasound may be utilized to better visualize certain anatomical parts of your baby. It is often performed at 24-32 weeks gestation. Likewise, it may be utilized if a birth defect is suspected.
Frequently Asked Questions
What is an OB ultrasound?
An obstetric (OB) ultrasound is an exam performed during pregnancy to ensure that your baby is growing and developing normally in the womb. It uses sound waves to create pictures of the baby, as well as the mother’s ovaries and uterus. This test is not harmful to the mother or baby and is the preferred method of monitoring pregnant women.
Is prenatal ultrasound safe?
Yes. There are no known risks associated with prenatal ultrasound. This procedure uses sound waves to create images, which are different than X-rays.
Can ultrasounds be wrong?
As with any test, there’s a possibility of error when it comes to a high-frequency ultrasound. These reasons can include factors like an incorrect gestation period, obesity or other health concerns, and technician error.
What does second-trimester ultrasound look for?
As a routine part of your second-trimester care, a high-frequency ultrasound will check your baby’s vital organs and growth to ensure everything is developing normally. It will also check fetal anatomy, the placenta, and amniotic fluid. This ultrasound can be performed transabdominally or transvaginally, based on your specific care needs.
Are ultrasound growth scans accurate?
Growth scans can be an important way to judge what kind of care you and your baby will need during labor and beyond. Although ultrasound technology has advanced greatly, there can still be factors that affect the accuracy of growth scans including obesity and technician error. In some cases, not all birth defects can be detected, and some abnormalities are too small to be seen.
When can an ultrasound determine the sex of my baby?
Yes, the gender of your baby can reliably be determined at 18-20 weeks gestation during an ultrasound. Be sure to let your sonographer know if you would like to know the sex of your baby, as some parents prefer to keep their child’s gender a secret until birth.
What is the difference between a topical and transvaginal ultrasound?
Topical ultrasounds are performed on the surface of the skin, while transvaginal ultrasounds are performed using a special probe that is inserted into the vaginal canal. The ultrasound technique that is used for you will depend on the reason for your ultrasound and how far along you are in your pregnancy.
When will I receive my ultrasound results?
Your healthcare provider may discuss your results directly following your ultrasound. However, in some cases, it may take a couple of days for your provider to review the ultrasound images and discuss their findings with you. If you have any questions or concerns regarding your ultrasound, please do not hesitate to reach out to our office.
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