Scans During Pregnancy: Complete Ultrasound Timeline

The first time you see your baby during pregnancy can feel unforgettable. It is also normal to feel worried. Many parents ask, "Is my baby growing well?", "Why do I need another scan?", or "Will everything be okay?"

That is why scans during pregnancy matter. These scans are also called prenatal scans or antenatal scans. They help your doctor check your baby’s growth, estimate your due date, look at the placenta, and spot concerns early.

Some scans are routine. Others are advised only when your pregnancy needs closer follow-up. If you need more scans, it does not always mean something is wrong. It often means your doctor wants a better view of your baby’s health.

Pregnancy Scan Timeline

Here is a quick look at the common types of scanning during pregnancy:

First Trimester Scans (Up to 13 Weeks)

Scans during first trimester pregnancy help confirm the pregnancy, give a more accurate due date, and check that your baby is growing as expected.

First Scan During Pregnancy (6 to 8 Weeks)

The first scan during pregnancy, also called the viability scan, is usually done between 6 and 8 weeks. It confirms the pregnancy and checks that it is developing in the usual way.

During this scan, the doctor checks that the pregnancy is inside the uterus. They look for your baby’s heartbeat, measure the crown-rump length (CRL) to estimate the due date, and see if you are carrying one baby or twins. In some cases, the scan may also show early problems, such as an ectopic pregnancy.

Some parents worry if the heartbeat is not seen during this scan. This does not always mean there is a problem. Sometimes the pregnancy is earlier than expected, so your doctor may repeat the scan after one or two weeks. If a transvaginal ultrasound is needed, it is considered safe for you and your baby.

12th Week Scan During Pregnancy (11 to 13+6 Weeks)

The 12th week scan during pregnancy is also called the dating scan or nuchal translucency (NT) scan. It is usually done between 11 weeks and 13 weeks 6 days. This scan helps confirm how far along you are, gives a more accurate due date, and can screen for some chromosomal conditions when combined with a blood test.

During the scan, the doctor measures your baby’s crown-rump length (CRL) and nuchal translucency (NT). They also check the nasal bone, heartbeat, placenta, and early growth of the brain, limbs, and abdominal wall.

A higher NT measurement can sound scary, but this scan is only a screening test. It is not a diagnosis. If the result shows a higher chance of a condition, your doctor may advise more tests. For many parents, this is also the first time they see their baby moving in the womb.

Wondering what other tests may be advised in early pregnancy? Explore our guide on Which Pregnancy Tests Are Necessary? Complete Guide to understand the purpose of common prenatal tests.

Second Trimester Scan (14 to 27 Weeks)

Scans during second trimester pregnancy give a closer look at your baby’s body. They can also help find conditions that may need extra follow-up or care.

Anomaly Scan (18 to 22 Weeks)

The anomaly scan, also called the TIFFA scan or Level II scan, is done between 18 and 22 weeks of pregnancy. It is a detailed ultrasound that checks your baby’s body parts and looks for structural problems.

During the scan, the doctor checks the baby’s brain, heart, spine, face, kidneys, stomach, bladder, limbs, placenta, umbilical cord, cervix, and amniotic fluid. They also measure growth using biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL).

Many parents feel nervous because the sonographer may stay quiet during the scan. This is normal. They need to focus while taking careful measurements. Your doctor usually explains the findings after the scan. This test can find many birth defects, but it cannot find every possible problem.

As your pregnancy moves forward, your baby’s movements become another important sign of wellbeing. Learn more in Reduced Baby Movements During Pregnancy: When Should You Worry?

Third Trimester Scans (28 Weeks Until Birth)

Scans during third trimester pregnancy focus on fetal growth monitoring, your baby’s wellbeing, and planning for a safe delivery.

Growth Scan During Pregnancy (28 to 32 Weeks)

The growth scan during pregnancy, also called the baby growth scan, is usually done between 28 and 32 weeks. It helps your doctor check whether your baby is growing well and whether the placenta is working properly.

During this scan, the doctor records measurements such as head circumference (HC), abdominal circumference (AC), femur length (FL), and estimated fetal weight (EFW). They also check the amniotic fluid index (AFI), placenta position, your baby’s movements, and your baby’s position.

If your doctor wants closer follow-up because of your baby’s growth, you may also have a Nonstress Test (NST) to check your baby’s wellbeing.

Doppler Ultrasound

A Doppler ultrasound is a more specialised scan. It is usually done after 28 weeks if your doctor needs to watch your baby’s blood flow more closely. Unlike a routine ultrasound, it checks how well blood moves between the placenta, umbilical cord, and your baby. This helps doctors see whether your baby is getting enough oxygen and nutrients.

During the scan, the doctor measures blood flow in the umbilical artery, middle cerebral artery (MCA), uterine arteries, and sometimes the ductus venosus. This scan is often advised if your baby seems smaller than expected, if you have high blood pressure or preeclampsia, gestational diabetes, or if there are concerns about how the placenta is working. Many parents worry when a Doppler scan is advised, but it is often done as a precaution.

Final Pregnancy Scan

The final pregnancy scan is usually done between 36 and 38 weeks, though not everyone needs it. This scan helps your doctor see whether your baby is ready for delivery and whether there are any concerns that could affect your birth plan.

During the scan, the doctor checks your baby’s position (head-down or breech), estimates fetal weight, measures the amniotic fluid index (AFI), looks at the placenta, and checks your baby’s overall wellbeing.

Towards the end of pregnancy, your doctor may also watch your baby’s movements and heart rate if there are concerns about fetal wellbeing.

Why Do Some Women Need More Scans?

A common question is, "My friend had only three scans, but I’ve had five. Is something wrong?"

Usually, no.

Doctors advise scans based on your own pregnancy. You may need more antenatal scans if you have gestational diabetes, high blood pressure, twins, an IVF pregnancy, reduced fetal movements, or concerns about your baby’s growth.

High-risk pregnancies often need extra follow-up, including ultrasound scans, NSTs, and Doppler studies. Learn Why Continuous Monitoring Is Important in High-Risk Pregnancy.

Are Pregnancy Scans Safe?

Yes. Ultrasounds use sound waves, not radiation. That makes them safe for mother and baby when trained healthcare professionals perform them.

For many years, fetal ultrasounds have been an important part of pregnancy care. They help doctors track development and spot concerns early. If you are ever unsure why a scan has been advised, ask your doctor. They can explain it clearly.

Conclusion

Every ultrasound during pregnancy has a purpose. Whether you are having your first pregnancy scan or a growth scan, each one gives useful information about your baby’s development.

Try not to compare your pregnancy with someone else’s. Some women need only routine ultrasounds. Others need closer follow-up. Both can be normal. Go to your appointments and follow your doctor’s advice. Each scan helps your care team support a healthy pregnancy.

Frequently Asked Questions

1. How many scans will be done during pregnancy?

Low-risk pregnancies usually include three or four scans. High-risk pregnancies may need more.

2. When is the first scan in pregnancy carried out?

The first scan is usually done between 6 and 8 weeks. It confirms the pregnancy, checks the heartbeat, and helps estimate the due date.

3. What is the function of the growth scan in pregnancy?

It checks your baby’s growth and estimated weight. It also looks at the placenta and amniotic fluid.

4. Can pregnancy scans pick all problems?

No. Pregnancy scans can find many problems, but not all of them.