Multiple gestations (carrying twins, triplets, or more) are unique experiences of pregnancy that come with similarly distinct needs and considerations for both the mother and baby. Your journey will look different from other pregnancies, from check-ups with your OB/Gyn to delivery.
These differences, of course, start with the ultrasound—whether 3D or 4D ultrasounds, mothers with multiple gestations tend to need them done more often. Frequency is increased because constant monitoring is required to observe each baby’s growth inside your womb, among other things.
Today, we’ll discuss what to expect during your ultrasounds for twins and multiple gestations so you can better understand how your pregnancy should progress.
Ultrasounds for Twins and Multiple Gestations
The frequency of ultrasounds for regular pregnancies is significantly lesser than for multiple gestations. For a regular pregnancy, a mother will only need a minimum of three ultrasounds, which can increase depending on specific cases or upon the mother’s request.
Mothers with twins or multiple gestations, on the other hand, may need weekly ultrasound appointments, which are often more comprehensive as visualization of each infant is necessary. These sessions will also cover check-ins to see if each fetus is receiving adequate nutrients and oxygen and assess the overall health of the pregnancy.
Each ultrasound focuses on a few specific areas depending on the pregnancy’s trimester.
The Initial Ultrasound
Purpose: To establish baseline health and initial risks.
What You’ll See: Two or more fetuses developing in your womb.
The initial or first ultrasound establishes the baseline of health we’re working with. During this appointment, we’ll check for multiple fetuses and count how many little ones are growing inside you. Once these are documented, we assess other aspects of your pregnancy, such as:
- Gestational age. This measurement determines how far along your pregnancy is by assessing fetal size and development markers. This part of the assessment allows us to ensure accurate timelines for growth milestones and check-ups.
- Chorionicity. This assessment determines whether your babies have their own placenta or are sharing one. This is essential information, as sharing a placenta (monochorionic pregnancy) can increase the risk of specific conditions, like twin-to-twin transfusion syndrome (TTTS), where blood flow between fetuses becomes imbalanced.
- Amnionicity. Here, we check if each baby has its own amniotic sac or if all babies are in a singular one. When each fetus has a separate sac, there is generally a lower risk of complications compared to situations where fetuses share an amniotic sac (monoamniotic pregnancy), which increases the risk of cord entanglement.
- Initial health indicators. Finally, this ultrasound screens for early signs of fetal health, including heart rate, size consistency, and any visible structural development. This helps identify potential complications early, ensuring appropriate monitoring and intervention strategies are in place.
Second Trimester Ultrasounds
Purpose: Done bi-weekly to monitor detailed anatomy, growth patterns, and development to ensure each baby grows and develops healthily.
What You’ll See: Detailed views of each baby’s body parts, including measurements of the head, abdomen, and limbs.
During the second trimester, weekly ultrasounds provide critical insights into each baby’s growth and development. These scans involve:
- Detailed anatomy scans. Weekly ultrasounds allow for comprehensive assessments of each baby’s body, helping us detect any developmental anomalies early. This includes monitoring the formation of each baby’s limbs, spine, and other anatomical features to ensure they are developing as expected.
- Growth measurements. We measure each baby’s head, abdomen, and femur to track individual growth patterns. This is particularly essential in multiple pregnancies, where differences in size or development could indicate issues such as growth restrictions or imbalances, signaling a need for closer observation or additional interventions.
- Organ development. Each scan also assesses internal organ development to confirm that vital structures are forming properly. Any discrepancies can indicate underlying conditions needing additional monitoring or specific care approaches.
Third Trimester Ultrasounds
Purpose: To assess fetal positioning, growth, and overall health as delivery approaches.
What You’ll See: Close-up views of each baby’s position in the uterus and assessments of their readiness for birth.
In the third trimester, weekly ultrasounds focus on critical aspects to ensure the babies are prepared for a safe delivery. These ultrasounds include:
- Position assessment. Each baby’s position within the uterus is monitored closely, as this helps determine the safest delivery method. Whether the babies are head-down, breech, or in another position, knowing this information is essential for delivery planning.
- Timing of delivery. Since many multiple pregnancies are delivered before full term, third-trimester ultrasounds guide decisions about the optimal time for delivery. The goal is to balance the benefits of additional development with any risks associated with continuing the pregnancy.
- Ongoing monitoring. Each baby’s size and growth trajectory are tracked to ensure they are progressing as expected. Consistent monitoring helps detect growth restrictions or imbalances that could impact their health at birth.
- Amniotic fluid and placental health. Fluid levels around each baby and placental function are assessed to confirm both are receiving adequate oxygen and nutrients. Abnormal fluid levels or signs of placental deterioration could prompt adjustments in care or timing of delivery.
Final Thoughts: Vigilant Monitoring in Multiple Pregnancies
For expectant parents of twins or multiples, weekly ultrasounds are a crucial part of ensuring a healthy pregnancy. Regular monitoring helps healthcare providers track fetal growth, assess amniotic fluid levels, and maintain placental health, all of which play a role in reducing complications. Understanding what to expect during these weekly appointments can help parents feel more prepared and confident about the health and development of their babies.
Weekly ultrasounds are a vital component of effective care in twin and multiple pregnancies, ensuring that every step is taken to support a safe and successful delivery. Consulting with an experienced OB-GYN provides further guidance and a personalized monitoring plan tailored to your pregnancy’s needs.
If you have questions about weekly ultrasound monitoring for twins or multiples, contact Roswell Ob/Gyn to learn how we can support your journey to a healthy birth.
