Ultrasounds are a cornerstone of modern obstetric care, providing you and OB-GYNs with vital insights into your reproductive health. During pregnancy, it’s first used to confirm the presence of and capture the first images of your developing baby. But its use doesn’t end there.
Throughout your pregnancy, you will need to have several ultrasounds. This consistent visualization helps us monitor how your baby is developing until your due date. Below, we’ll detail the series of ultrasound tests you must have during pregnancy and why.
Typical Ultrasound Schedule During Pregnancy
On average, a low-risk pregnancy involves two to three ultrasounds, which are primarily used to monitor your baby’s development and ensure that the pregnancy progresses smoothly. Each ultrasound serves a specific purpose, depending on the trimester. We discuss these below.
First Trimester Ultrasound — Between 7 and 13 Weeks
The first-trimester ultrasound confirms the pregnancy and determines your baby’s gestational age. During the scan, we’ll check for your baby’s heartbeat, assess where your baby is growing, and verify if you are carrying twins or triplets (multiple pregnancies).
These assessments are critical to mapping out the prenatal care you’ll receive until the baby is delivered. Detecting multiple pregnancies or any anomalies in your baby’s heartbeat, for instance, will necessitate specialized interventions.
In such cases, you will be referred to a high-risk pregnancy OB-GYN for more specialized care and attention that will help ensure your and your baby’s safety and health.
Second Trimester Ultrasound — Between 18 and 22 Weeks
The second-trimester ultrasound is often referred to as the anatomy scan, as it is usually done when the baby has developed much of the vital organs that continue to support its growth. Specifically, we will check for the following and help ensure that you and your baby receive the appropriate care based on the findings.
- Spinal development and limb formation: The ultrasound helps check for abnormalities in the baby’s spine, such as spina bifida, in which the spinal cord doesn’t develop properly. Additionally, we’ll check for any discrepancies in limb length or missing bones that might indicate genetic conditions.
- Placenta’s position: Ultrasound is used to check the placenta and determine whether it is positioned normally or covers the cervix — a condition called placenta previa. Identifying and addressing this early is critical to minimize risks of complications, such as bleeding during delivery.
- Amniotic fluid levels: Amniotic fluid plays a vital role in protecting and cushioning your baby in the womb. It also supports the development of your baby’s lungs and digestive system. An ultrasound measures the amount of amniotic fluid to ensure it is within the normal range.
Third Trimester Ultrasound — Between 28 and 40 Weeks
An ultrasound in the third trimester aims to evaluate your baby’s size, position, and overall well-being before the delivery. If you are a low-risk pregnancy, these ultrasounds will primarily check to see if your baby is in an ideal position for the delivery.
Specifically, we’ll watch out for positions like:
- Cephalic Position: This is the ideal delivery position, where your baby is head-down with the chin tucked into the chest and the back of the head presenting first. The baby is aligned with the birth canal, allowing a smooth and natural delivery. If the baby is in this position, your OB-GYN will typically order the delivery as you prefer.
- Breech Position: In the breech position, the baby is positioned bottom-first instead of head-first, possibly complicating the delivery process. If the baby is in breech, vaginal delivery can be risky because the head is delivered last.
To address a breech position, healthcare providers may attempt an external cephalic version (ECV) to manually turn the baby to a head-down position before labor begins. If ECV does not correct the position, a cesarean delivery may be recommended.
- Transverse Lie: In a transverse lie, the baby lies horizontally across the uterus, making vaginal delivery impossible. If a baby remains in a transverse lie as the due date approaches, a cesarean delivery is usually planned to deliver the baby safely. Healthcare providers may also try to reposition the baby using an ECV.
- Oblique Lie: An oblique lie occurs when the baby is positioned diagonally in the uterus, with the head or buttocks pointing towards one of the mother’s hips. This position is unstable and can change to transverse or longitudinal during labor. Like the transverse lie, an oblique lie prevents a safe vaginal delivery because the baby is not aligned with the birth canal.
- Face and Brow Presentation: Face presentation occurs when the baby’s head is extended backward so that the face, rather than the top of the head, presents first. In brow presentation, the baby’s head is slightly extended, with the forehead aimed at the birth canal.
Both positions can make delivery challenging due to the larger diameter of the presenting part compared to the pelvis, increasing the risk of prolonged labor and trauma to the baby.
Cases When You Might Need Additional Ultrasounds
High-risk pregnancies or if monitoring reveals any issues in fetal development, you may need additional ultrasounds to maintain constant monitoring of the baby. These additional scans are necessary for informing healthcare providers about the appropriate care we need to administer to help see you through a safe and healthy delivery.
In high-risk pregnancies, for instance, frequent ultrasounds help healthcare providers keep a close eye on your baby’s development and quickly address any potential issues. For example, if you have gestational diabetes or high blood pressure, you might have additional scans to monitor your baby’s growth and ensure the condition is managed effectively.
Later on, when interventions are successful, you can expect the ultrasounds to become less frequent, significantly if your and your baby’s health normalizes before the delivery date.
Final Thoughts
Ultrasounds are an integral part of prenatal care, providing crucial information about your and your baby’s health and development. By monitoring your pregnancy through regular ultrasounds, healthcare providers can ensure that any potential issues are identified and addressed early, helping to ensure a safe and healthy pregnancy and delivery.
Sticking to the recommended ultrasound schedule is essential for tracking your baby’s growth and development and provides peace of mind for expectant parents. By attending each scheduled scan, you can stay informed about your pregnancy’s progress and make the best decisions for you and your baby’s health.
If you have questions about your ultrasound schedule or want more information about the services offered at Roswell Ob/Gyn, please contact our clinic. Our experienced team is here to support you throughout your pregnancy and provide the care and information you need.
