Your 12-week scan (around 11 to 13 weeks) confirms your baby's heartbeat, screens for chromosomal conditions and locks in your due date, while the 20-week scan (around 18 to 22 weeks) is a detailed, head-to-toe anatomy check that can also reveal your baby's sex.
Few moments in pregnancy feel as big as seeing your baby on the screen for the first time. Your 12-week and 20-week scans are the two milestones most parents count down to, and it's completely natural to wonder how they differ and what we're actually looking at.
At Athena Women's Clinic in Bentley, we understand exactly how much you want to know what's happening. This simple guide walks you through what our sonographers look for during your pregnancy ultrasounds in Perth, so you can walk in feeling calm and prepared.
| At a glance | 12-week scan | 20-week scan |
|---|---|---|
| Also known as | Nuchal Translucency (NT) scan | Morphology (anatomy) scan |
| Usual timing | 11 to 13 weeks | 18 to 22 weeks |
| Main focus | Heartbeat, chromosomal screening, early anatomy and your due date | Detailed head-to-toe anatomy, growth, fluid and placenta position |
| Bladder prep | Very full — two large glasses of water | Moderately full — one glass of water |
Your 12-Week Scan: What Are We Looking For?
This scan usually happens between 11 and 13 weeks, and you may hear it called the Nuchal Translucency (NT) scan. For most parents it brings enormous reassurance: the very first thing we do is confirm your baby's heartbeat, and then we look closely at their early physical development.
Here's what our sonographers focus on at this early stage:
- Chromosomal screening: We gently measure the fluid at the back of your baby's neck, which helps us assess the risk of conditions like Down syndrome.
- Early anatomy: We check the brain, limbs and abdominal wall.
- Placenta and due date: We locate the developing placenta and confirm your official due date using precise measurements.
Your 20-Week Anatomy Scan: The Detailed Check
We usually carry out this detailed scan between 18 and 22 weeks — you might know it as the "morphology scan." It's a comprehensive, head-to-toe check, and because your baby has grown so much by now, we can see even the tiny details very clearly.
So what are our sonographers examining this time?
- Detailed anatomy: We carefully examine the heart chambers, brain structures, kidneys and spine.
- Growth and fluid: We measure your baby's head, abdomen and thigh bone, and check the exact volume of amniotic fluid around them.
- Placenta position: We check that the placenta sits safely away from your cervix, keeping a clear path for delivery.
- Gender reveal: Would you like to know the sex of your baby? Our sonographers can usually tell you at this stage — just let us know your preference before we begin.
How to Prepare for Your Pregnancy Scans
A little preparation goes a long way, and it changes slightly between the two appointments — mainly when it comes to your bladder.
- For the 12-week scan: You'll need a very full bladder, so drink two large glasses of water an hour before your appointment and don't empty your bladder beforehand. The water gently lifts your uterus for a perfect view.
- For the 20-week scan: Your baby takes up much more space by now, so you only need a moderately full bladder — just one glass of water before you arrive.
Wear comfortable two-piece clothing to both appointments — we simply need easy access to your tummy.
Athena Women's Clinic works alongside our sister clinics. For regenerative skin, hair & body treatments see Athena Wellness; for pregnancy & pelvic imaging see Athena Women's Ultrasound.
