What Is an Obstetric (Above 16 Weeks) Ultrasound?
As you enter your second trimester, is it routine to have another ultrasound to check in on your baby’s development. The scan normally occurs between the 18th and 22nd week of your pregnancy. Obstetric ultrasound is known as the anatomy scan, as your baby has been rapidly developing its essential organs and tissues. During this examination, the technician (sonographer) will focus on analyzing the vital organs and taking measurements to ensure the baby is healthy developing and properly. Since the sex organs of the baby have developed, you are able to find out the sex of the baby – if you would like to know. The obstetric ultrasound procedure will be very similar to the ultrasound taking during your first trimester and there is no risk posed with this diagnostic tool. The second semester ultrasound is very important for two reasons; first, it provides an update on the development of your baby; secondly, it is critical for diagnosing any abnormalities that need to addressed before your delivery date.
What Will Be Visualized and Looked at During the Obstetric Ultrasound?
Since this is an anatomy scan, there are multiple organs and tissues that need to be visualized by the sonographer; this is done in order to check for proper development and ensure no defects or abnormalities. Listed below are examples of what may be assessed during the ultrasound.
- Assessment of the shape and structure of the baby’s head, as well as any brain abnormalities
- Assessment of the baby’s face and identification of a cleft lip or palate defect
- Assessment of all four chambers of the heart to ensure size of the atria and ventricles, steady blood flow through the heart with proper valve opening and closing, and monitoring of the fetal heartbeat
- Alignment of the spine, to ensure normal spacing and curvature; assurance that the skin is covering the spine
- Assessment of the stomach, diaphragm and chest
- Assessment of the kidneys to ensure there are two and ensure that urine is passing through the bladder properly
- All limb extremities are checked, as well fingers and toes will be assessed
- Placenta position will be monitored in relevant distance to the cervix
What Measurements Are Taken During the Ultrasound?
There are multiple important measurements to be taken in the second trimester ultrasound. They include but not limited to:
- The baby’s head circumference and biparietal diameter
- Humerus length
- Femur length
- Abdominal circumference
- Binocular distance (measurement of distance between the eyes)
- The number of fetuses
- The volume of amniotic fluid that is present in the baby
- The length of the cervix
- The condition of the uterus