< 14 weeks
OB First Trimester (6 weeks to 14 weeks Pregnant)
Having an early OB Ultrasound is one way your physician can establish your due date if there is a question of when you might have conceived.
If you do have an ultrasound early in your pregnancy, please remember you have to be at least 6 weeks pregnant in order to see the baby’s heartbeat.
Ultrasound is a sensitive modality but the baby does need to grow big enough to accurately measure and see the heartbeat and usually this is around 6 weeks gestation. After 6 weeks pregnant, a fetal heartbeat should reliably be seen on Ultrasound.
An Early OB ultrasound is performed to not only establish a due date but determine the viability of the early pregnancy. Sometimes patients are having bleeding problems, are unsure when they might have conceived or are at risk for miscarriage.
Once a fetal heartbeat is seen on Ultrasound, the likelihood of a patient miscarrying is typically less than 10%. However, there are lots of factors that can affect a woman’s pregnancy and subsequent health of the baby.
Some of the anatomical structures that we can see in an early OB pregnancy depend on how far along you are at the time you receive the early OB ultrasound.
Patients that are 6 to 10 weeks pregnant: The baby is often referred to as a “fetal pole”. The fetus can be measured in its entire length from head to rump.
Because the limbs are not formed yet, the most accurate way to determine the gestational age of the baby is to measure the crown rump length. Early in this age range the baby’s movements are not well seen on ultrasound. However, as the baby advances to the 10 week mark and beyond, small fetal movements become more visible on ultrasound. Usually it is the trunk of the baby you can see moving. A fetal heartbeat is visible during this timeframe as well.
Patients that are 11 to 14 weeks pregnant: It is quite amazing the changes the baby has in just a few weeks. Fetuses that are in these gestational ages start to look more defined with an obvious head, limb buds or arms/legs etc. The fetal heartbeat is more obvious and fetal movement is more visible.
The baby can be measured in its entire length up to 13-14 weeks pregnant. A crown rump length is a measurement that gives your physician the gestational age of the baby by measuring the top of the baby’s head to the rump of the baby. The limbs (arms or legs) are not included in this measurement.
Some of the things the sonographer will be looking for is fetal movement, fetal heart tones, the fluid around the baby, placenta formation etc.
OB < 14 weeks Pregnant
This type of Diagnostic ultrasound requires a physician or provider order prior to performing exam.
ALL patients needing early Obstetric ultrasounds need to have a full bladder when they arrive for their ultrasound appointment.
The best way to achieve a full bladder is to drink 32 ounces of any kind of fluid and finish that fluid 1 (one) hour prior to your appointment time.
For example: If you have a 2:00 pm Ultrasound appointment, please have 32 ounces of fluid finished by 1:00 pm. This allows the fluid you drank to get to your bladder for your 2 pm appointment. Remember don’t go to the bathroom until after your Ultrasound has started.
10 weeks Pregnant or Less:
Your Ultrasound exam will typically require an Endovaginal approach in addition to the full bladder technique. In order to have a transvaginal ultrasound, you will be asked to empty your bladder. After using the restroom, you will be asked to undress from the waist down, lay on an exam bed possibly in stirrups with a sheet that ensures privacy.
An endovaginal ultrasound is a technique where the Sonographer holds an Ultrasound probe that is inserted into the vagina. The patient is often asked to insert the probe or offer assistance to ensure patient comfort. Transvaginal Ultrasound is the best way to evaluate an early pregnancy because it usually the only way we can visualize a small fetus with a heartbeat.
11 Weeks Pregnant to 14 Weeks Pregnant:
Babies are usually big enough to see transabdominally (through the top of mom’s belly). The full bladder helps to visualize the uterus and provide a great window into the pregnancy.
Sometimes a transvaginal ultrasound is necessary if the uterus is tilted, but typically ultrasounds in this gestational age range are done externally.
All of the images from your ultrasound will then be sent to a Radiologist (interpreting physician) for a report to be generated for your referring physician. You will receive the results of your Ultrasound from your referring physician or the provider who ordered this ultrasound to be performed. Please refer back to the physician's office who sent you to obtain results of your ultrasound exams.