Fetal Anomaly Scan Singapore: 20-Week Ultrasound & Baby Check

Imagine you're lying on that examination table, gel on your belly, watching your baby's heart beat on the screen for the first time. Those feelings of excitement mixed with nerves? That's exactly what makes your 20-week anomaly scan such a big deal.

If you're feeling anxious about this appointment, you're not alone. Most parents swing between excitement to see their baby and worry about what the scan might find. This isn't just another appointment to tick off your list. It's your chance to properly meet your little one and hopefully get some reassuring news about how they're growing.

What exactly is a fetal anomaly scan?

Your anomaly scan is basically your baby's first proper health check-up. It happens around 20 weeks (smack in the middle of your second trimester), and doctors sometimes call it a level 2 ultrasound scan or mid-pregnancy scan.

Think of it as the detailed version of your regular ultrasound scans. While your earlier scans focused on dating and basic checks, this one goes deep into your baby's development. During the scan, your doctor will look closely at your baby’s organs, bones, and growth to see how everything is developing. They’ll also check the placenta, amniotic fluid, and umbilical cord to make sure your little one has a safe and healthy space to grow.

What does your sonographer actually look for?

The anomaly scan is thorough. Your sonographer will check your baby from head to toe during this scan.

• Brain development:

  • Your sonographer checks your baby's brain size, the fluid-filled spaces called ventricles, and how the cerebellum is forming. This gives them great insight into your baby's neurological development.

• Facial features:

  • They look carefully at your baby's eyes, nose, and lip formation. This helps spot conditions like cleft lip early in pregnancy.

• Heart function:

  • This is probably the most important part of the whole scan. The sonographer examines the heart chambers, valves, and blood flow patterns to catch any potential heart issues.

• Abdominal Organs:

  • The scan reviews your baby's stomach, kidney, bladder, and liver development. Seeing these organs form properly is incredibly reassuring for parents.

• Spine development:

  • Your sonographer makes sure your baby's spine is closed and aligned properly. This rules out conditions of neural tube defects such as spina bifida (when the spine doesn't close properly during development).

• Arms and legs:

  • They carefully check bone length, symmetry, and those tiny fingers and toes. The sonographer watches for normal development and movement patterns.

• Placental position:

  • The location of your placenta gets checked because it affects your delivery options. If you have placenta praevia, this affects how your birth will be planned.

• Amniotic fluid levels:

  • Your sonographer looks for the perfect balance - not too much fluid, not too little. Abnormal levels might need some extra monitoring throughout your pregnancy.

• Umbilical cord check:

  • The cord should have three vessels: two arteries and one vein. Your sonographer makes sure everything's connected properly for optimal nutrition flow.

• Cervical length:

  • Sometimes your sonographer will measure your cervix. A shorter cervix can signal a higher risk of preterm labour (labour starting before 37 weeks), so your team can plan extra support if needed.

Feeling a mix of excitement and nerves is completely normal. If you’d like, you can take a moment to jot down any questions or concerns to bring to your appointment. It can help you feel more prepared and connected to your baby during the scan.

Why is the 20-week ultrasound scan done?

Twenty weeks is the sweet spot for this detailed scan, and here's why it works so well:

• Early detection of issues:

  • The scan can catch problems like heart issues, spina bifida, or kidney problems early. This gives you time to plan and get specialist help if needed.

• Growth monitoring:

  • Your doctor makes sure your baby's growing well. Larger babies might signal gestational diabetes, which needs extra attention.

• Planning your care:

  • If anything comes up, your team can plan ahead for the best outcomes. This might mean arranging birth at a specialist centre or discussing a caesarean section if that's the safest option.

At 20 weeks, your baby's organs are developed enough to see clearly, but there's still time to plan if anything needs attention.

How does a 20-week ultrasound scan work?

The scan uses high-frequency sound waves to create real-time images of your baby. After applying some gel to your belly, a small device called a transducer is placed on your abdomen to capture the images.

The sound waves bounce off your baby's body and return to the machine, which turns them into the pictures you see on the screen. There's no radiation involved, so it's very safe for both you and your baby.

What to expect during the scan?

Your appointment will take anywhere from 20 to 45 minutes, though it might run longer if your baby is wriggling around or positioned in a tricky spot.

• Before you start:

  • When you arrive for your ultrasound scan, you'll lie back comfortably on the examination table. The table can tilt if you need some pressure taken off your back as your belly grows.

• During the scan:

  • The sonographer will apply gel to your belly (it feels cool at first), then gently move the transducer around to get clear images..

  • If your baby is positioned in a way that makes it hard to get good measurements, the sonographer might ask you to move around a little or change positions to help get clearer views.

• Meeting your baby:

  • You'll watch your baby on the monitor while the sonographer points out different body parts as they check everything.

Do you need to prepare beforehand?

The good news is that you don't need to prepare much for your anomaly scan. There's no fasting required, so you can eat normally before your appointment. Just wear loose, comfortable clothes that give easy access to your belly. Consider bringing your partner for moral support. That's honestly the most important thing you can do to prepare.

What do the results of a 20-week ultrasound tell you?

Your obstetric ultrasound report covers everything important about your baby's development and your pregnancy environment.

• Growth measurements:

  • The report includes your baby's head, belly, and thigh bone measurements to estimate current weight and track development.

• Anatomy assessment:

  • You'll get a detailed review of how your baby's organs and bone structure are developing.

• Your pregnancy environment:

  • The report covers placental position and amniotic fluid levels, plus notes any visible differences from typical development.

If anything looks a little different, your doctor may suggest another scan or test, mainly to take a closer look and to make sure you and your baby get the right care.

What conditions can the scan detect?

Your fetal anomaly scan can spot many structural conditions, though detection rates vary:

• Brain and spine issues:

  • Neural tube defects like spina bifida and anencephaly are usually very clear on scans, giving you definitive information early.

• Heart conditions:

  • The scan checks cardiac chambers, valves, and major vessels thoroughly. If anything complex is suspected, you'll get referred for specialist heart scans.

• Facial differences:

  • Cleft lip and sometimes cleft palate can often be seen clearly. Additional imaging is available if you need more detailed information.

• Limb development:

  • The scan can detect missing or shortened arms and legs, extra digits, and checks movement and bone development patterns.

• Abdominal wall problems

  • Conditions like gastroschisis, where organs develop outside the tummy, are usually very clear to see on scans.

• Kidney and bladder issues

  • The scan checks that your baby's urinary system is present and functioning normally. Sometimes enlarged or absent kidneys show up, which means you'll need extra monitoring.

• Chromosomal abnormalities

  • Physical markers might suggest conditions like Down syndrome, but you'll need genetic blood tests for a definitive diagnosis since scans can't confirm genetics.

Most scans show normal development. Finding something early means your doctor can plan the safest care for you and your baby.

Will you need further tests or ultrasounds?

Depending on your results, you might be offered additional testing to get more detailed information about your baby's condition.

• Specialist appointments: 

  • You might get referred to foetal medicine units for detailed follow-up care, including maternal foetal medicine consultations.

• Heart-specific scans: 

  • A foetal echocardiogram provides specialised cardiac evaluation if heart issues are suspected.

• Genetic testing: 

  • Blood tests, amniocentesis, or chorionic villus sampling can provide definitive genetic diagnosis when needed.

• Follow-up monitoring: 

  • You might need growth scan appointments later in pregnancy or repeat ultrasound scans if your baby was being uncooperative.

Sometimes you need repeat scans just because of the baby's position, not because anything's wrong.

Is the fetal anomaly scan safe?

Yes, it’s completely safe for both you and your baby. Ultrasound scans use sound waves, not radiation, and have no known harmful effects on you or your baby. They’re a routine part of pregnancy care worldwide. 

It's completely non-invasive and safe for both you and your baby throughout pregnancy.

FAQ

Is the fetal anomaly scan mandatory?

It's your choice, but it's strongly recommended. The information helps plan the best care if anything needs attention.

Which week is best for an anomaly scan?

Between 18-22 weeks, with 20 weeks being ideal. Your baby's organs are clear enough to see properly.

Does a normal anomaly scan mean everything is perfect?

A normal scan is very reassuring, but no test can guarantee everything. It catches most major issues though.

What should I do if I feel anxious before the scan?

It's totally normal to feel nervous. Bring someone with you, practice some breathing, or chat with your midwife about your worries.

What if my baby isn’t in the right position during the scan?

This happens frequently. You might need to move around, take a walk, or come back another day for clearer pictures.

What if the scan shows something unusual?

If anything's spotted, you'll get extra scans or tests for more information. Your care team will explain everything and support you through it. This scan is about giving you information and peace of mind. Most babies get the all-clear, and even if something comes up, early detection means better planning for you and your little one.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice based on your unique situations, please consult a specialist at Thomson Medical. Request an appointment with Thomson Medical today.