The Big Ultrasound: What You'll Learn About Baby This Week

Your baby is developing rapidly at 18 weeks, and the anomaly scan helps you see these changes clearly. During the scan, the sonographer looks at your baby’s organs, limbs, and overall growth. You can observe movements, and sometimes even spot little details like their fingers, toes, or facial features. It’s a useful step to check that everything is on track at this stage.

Pregatips.com
You’re 18 weeks pregnant, and this is an important stage as you get closer to the halfway mark of your pregnancy! One of the big moments this week is the detailed foetal anomaly scan. This ultrasound lets you get a closer look at your baby and how they’re growing.
You might be curious to see how active they are, or maybe you just want some reassurance that everything’s going well. It’s also a good time to ask any questions you have and get a better idea of what’s happening with your pregnancy right now.

What Is the Anomaly Scan?

The anomaly scan is a special ultrasound that checks your baby’s physical development in detail. It’s usually done around 18 to 22 weeks because this is when your baby’s organs and body parts are developed enough to be seen clearly on the ultrasound.

The scan uses sound waves to create 2D, 3D, or even 4D images of your baby, showing how they’re growing and if there are any structural concerns. It’s a safe procedure with no harmful rays involved, just sound waves to capture those precious pictures.

What Does the Anomaly Scan Check For?

During the anomaly scan, the sonographer will carefully examine your baby’s body to make sure everything is developing properly. They’ll take measurements and look at specific organs and body parts to check for any abnormalities.

This is what they focus on:

Head and Brain

They check the size and shape of the skull and look at brain structures like the ventricles and cerebellum. This helps spot issues like fluid buildup (hydrocephalus) or neural tube problems such as spina bifida.

Face

The eyes, nose, and lips are examined to detect conditions like cleft lip or palate. The nasal bone is also looked at as it can be a marker for chromosomal conditions.

Spine

The vertebrae are checked for proper alignment and closure to rule out spina bifida or other spinal issues.

Heart

The four chambers of the heart, blood vessels, and heart rhythm are closely studied to detect congenital heart defects.

Abdomen

The stomach, kidneys, and bladder are checked for proper placement and function. They also look for defects like gastroschisis, where organs develop outside the body.

Limbs

The arms, legs, hands, and feet are measured and checked for movement. Conditions like clubfoot or missing limbs can be spotted.

Thorax and Lungs

The lungs are examined for symmetry, and the diaphragm is checked for proper movement.

Umbilical Cord and Placenta

The cord is checked for the number of blood vessels and its insertion point. The placenta’s position is also checked to make sure it’s not covering the cervix (placenta previa).

Amniotic Fluid

The amount of fluid around your baby is measured to ensure it’s at a healthy level, not too much (polyhydramnios) or too little (oligohydramnios).

Overall Growth

Measurements like head circumference and femur length are taken to confirm your baby is growing well for their gestational age.

What Happens During the Anomaly Scan?

The anomaly scan usually takes around 45 minutes and is done by a trained sonographer. You’ll lie back on the exam table while they put a special gel on your belly so the device slides smoothly. As they move it around, you’ll see images of your baby on the screen.

You might see them drawing lines on the screen to measure your baby’s limbs, head, or belly. If your baby isn’t in a good position, the sonographer might ask you to move a bit or drink something sweet to encourage movement.

Your Body at 18 Weeks of Pregnancy

Your body is changing fast to keep up with your growing baby. This is what you might notice:
  • Your belly is growing and sits just below your belly button. Everyone’s bump is different, so don’t worry if yours looks small or big.
  • You might feel some backaches as your body adjusts. Try a warm bath or putting your feet up to feel better.
  • Appetite and food cravings may increase.
  • Heartburn, leg cramps, swelling in your feet or ankles, dizziness, and extra discharge are all pretty common.
  • Move slowly when standing up to avoid feeling lightheaded.

Your Baby at 18 Weeks of Pregnancy

Your baby is also getting bigger and more active. This is what you can expect at 18 weeks:
  • Your baby is about 14 cm long and weighs around 190 grams.
  • Fingerprints are forming, and little facial features are starting to look more defined.
  • Your baby’s senses are growing, and they can hear your heartbeat and voice.
  • You might start feeling tiny kicks and movements, this is called quickening.
  • Their lungs, digestive system, and skeleton are developing, and hair and nails are starting to appear.
The 18-week anomaly scan is an important step in your pregnancy. It can confirm that major organs and structures are forming well and show how active your baby has become. This scan offers reassurance as you witness your baby’s progress up close!

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FAQs on The Big Ultrasound: What You'll Learn About Baby This Week

  1. What is the next scan after an anomaly scan?
    The next routine scan is usually the growth scan around 28 to 32 weeks to check the baby’s size, position, and amniotic fluid levels.
  2. What is the difference between foetal echo and anomaly scan?
    A foetal echocardiogram (foetal echo) focuses specifically on the baby’s heart to check for structural or functional issues. An anomaly scan looks at the overall growth and development of all major organs and body parts.
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