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What to expect at your 20-week pregnancy scan

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Can you believe it? You’re halfway through your pregnancy. You’re passed the morning sickness and exhaustion phase and now get to enjoy little kicks, flutters, and hiccups occurring in your belly. 

It really is one of the best stages of pregnancy. Your belly is showing nicely, your skin and hair are radiant, and you can still sleep comfortably. 

It’s now time for your 20-week ultrasound. It’s an important prenatal screening as your baby is big enough for healthcare providers to detect any anomalies. But it’s also a chance for you to see your developing baby in 3D and learn their sex (if you can’t wait). 

At this appointment, a trained technician or sonographer will use high-frequency sound waves to take various measurements of your baby. They’re checking to ensure your little one is developing as expected. Learn more about ultrasounds here.

It’s normal to feel nervous. Will your baby have ten fingers and ten toes? What if you learn there’s something wrong? To help put your mind at ease, we’ve included everything you need to know to prepare for your scan.

How many months pregnant are you at 20 weeks?

At 20 weeks, you are five months into your pregnancy, roughly halfway. By now, your baby measures 16 cm and is the size of a cantaloupe. Their eyebrows have formed, and their bones are beginning to harden. 

What is the 20-week anatomy scan looking for?

During the 20-week ultrasound, the sonographer or neonatal specialist is looking for major abnormalities or birth defects such as: 

  • down syndrome
  • congenital heart defects
  • spina bifida
  • cleft lip or cleft palate
  • diaphragmatic hernia
  • anencephaly
  • gastroschisis 
  • exomphalos
  • lethal skeletal dysplasia

During the 3D ultrasound, the sonographer will closely examine the four chambers of your baby’s heart to ensure they’re developing properly. They will listen for abnormal rhythms. 

They will analyse the placenta to ensure you’re not at risk of experiencing placenta previa. The sonographer will check the umbilical cord to make sure blood flow is good, and they’ll also measure how much amniotic fluid surrounds your baby. Too little is an early sign of disease. 

They will also examine the kidneys and check to see if there is fluid in the bladder. 

Should the sonographer identify potential medical issues, your healthcare team has enough time to plan a course of action.

How long does the 20-week scan take?

The scan is completely painless and can take between 30 and 45 minutes, depending on how cooperative your little one is.

Can my partner come with me to the scan?

Absolutely. Whether you bring a friend, family member, or partner to the scan is up to you. But it’s worth having support in case the sonographer detects an anomaly.

Can the scan harm my baby?

The 20-week scan is perfectly safe for you and your unborn child. While we recommend that all expectant moms book a 20-week prenatal scan, know that you might receive difficult news. 

If your baby has a terminal or life-threatening medical condition, you will need to make tough decisions. For example, your doctor may want to run further tests, which can result in a miscarriage. Having someone there to support you is vital.

How common is bad news at a 20-week scan? 

Your 20-week ultrasound is a nerve-wracking time. This scan takes an in-depth look at your baby’s organs to ensure they’re developing as expected.

If your little one has a health condition, we should be able to pick it up. That said, some birth defects or anomalies won’t be detected during the anatomy scan. 

If the sonographer is concerned, they will book a follow-up scan and consult with your attending obstetrician. If your unborn baby has a serious birth defect, your healthcare team will enlist the help of a therapist or counsellor.

What should you expect at the 20-week ultrasound appointment? 

Before the scan

Medical appointments always run over, so give yourself time. Plan to arrive early so you can fill in any forms and get your blood taken. Try not to empty your bladder before the appointment. 

When the fetologist is ready to see you, you’ll then be ushered into the sonographer’s rooms, where they’ll explain what’s going to happen and what they’re looking for. 

If you don’t want to know the sex of your baby, tell the sonographer before the scan begins so they can tell you to look away when examining that area.

During the scan

The rooms are dimly lit so you can see the monitors. The sonographer will ask you to lie down on the bed and lift your shirt. They’ll tuck a paper towel into the waistband of your pants and under your shirt so you don’t get any of the ultrasonic gel on your clothes. 

The cool gel is then applied to your abdomen before placing a handheld probe on your belly. A grainy black-and-white image will appear on the ultrasound screen. The sonographer will explain to you exactly what they’re looking at (and what they’re looking for) during the scan.

They’ll freeze the frame to take pictures and measurements of the different parts of your foetus. Expect to see them draw lines to measure the length of your unborn baby’s limbs and the circumference of its head. 

This helps them to get an accurate gestational age of your baby. 

The sonographer needs to concentrate while examining your baby, so don’t panic if they’re not chatty during the scan. They will share their findings once they’ve completed their scans.

After the scan

Once the scan is complete, the gel will be cleaned off your belly, and you’ll be sent home with a few pictures to enjoy and share with friends and family.

When will I know the results of my scan?

Your results will be ready by the end of the scan providing further tests are not required. The sonographer or fetologist will brief you on their findings. 

Reading the scan: What does a baby girl vs boy look like?

If you want to know the sex of your baby, look for three white lines for a baby girl and a protrusion from a round sack for a boy. To be 100% sure, just ask your obstetrician or the sonographer to show you.

Here are some features that can be easily identified from the scans.

20 week fetal scan heart chmabers
Image 1: 4 Chambers
20 week fetal scan Abdominal circumference
Image 2: Abdominal circumference measurement
20 week fetal scan nasal bone
Image 3: Nasal bone
20 week fetal scan 5 fingers
Image 4: 5 fingers

Book your 20-week appointment

Once you’re through the first trimester, it’s best to book your 20-week ultrasound, as it can be tough to get an appointment last minute. It’s an exciting and nerve-wracking time. If you’re worried, please share your concerns with your obstetrician. They’ll help to set your mind at ease. 

ERAD has radiology departments across Namibia. Speak to your gynaecologist beforehand and book your 20-week pregnancy ultrasound at ERAD.

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