At 12 weeks pregnant, you'll finally be able to see your little one for the first time – probably the first major event you look forward to when you're expecting. The 12-week ultrasound scan can actually happen anywhere between 11 and 13 weeks. At this stage, believe it or not, all your baby's limbs, organs, bones, and muscles will be fully-formed. However, you may be wondering what exactly happens at the scan. Read on to find out more.

What Happens at a 12 Weeks Ultrasound Scan?

During the scan, high-frequency sound waves are emitted from a hand-held device, known as a transducer, through the abdomen. When the waves come into contact with solid tissue, this is imaged on a screen to be interpreted by a sonographer.

To get a clear image, drink lots of water beforehand in order to lift up the uterus. In the procedure, the sonographer will squeeze some cold gel onto your abdomen and gently slide the transducer over the region.

At 12 weeks, the fetus's eye sockets, forehead, and a small button nose can all be seen on the scan. Your baby now has a definite human appearance.

The sonographer will talk through the procedure. He or she can show you the screen, or you may have your own separate screen. You can always ask your sonographer to tell you what they are examining at each point.

If they have any uncertainties, the sonographer may ask a colleague to examine the ultrasound scan. This can be unsettling, particularly if you thought everything was going ok, but the sonographer can tell you why they are doing this.

Here is a video of a typical 12-week ultrasound scan, so you know what to expect when viewing the screen: 

How Is Your Baby Developing at 12 Weeks?

Your baby will still be very small – about 6 cm long. However, he or she will be fully formed, with all the organs in place. The next phase is simply to grow, as well as practicing breathing and sucking movements. You'll probably have the 12 weeks pregnant ultrasound now, but the gender won't be obvious yet.

• Skeleton: At 12 weeks, the fetus's skeleton is formed from cartilage, but this will gradually harden into bone over the next few weeks. Newborn babies have a skeleton consisting of more than 300 pieces of bone and cartilage, but the bones fuse together during growth to become bigger and stronger, so the adult body has 206 separate bones.
• Intestines: Your baby's organs are also rapidly developing at 12 weeks gestation. The intestines, which were previously growing so quickly they protruded into the umbilical cord, are now regressing back into the abdomen and the kidneys are starting to excrete urine into your baby's bladder.
• Movement: Your baby will be moving about your womb a lot, although they are so small you won't feel anything. As they move, their wrists and elbows bend. The eyelids are still fused shut, but they have now moved from the side of the head to the final position at the front.
• Reflexes: This is also the week your little one starts practicing reflexes, including clenching the eye muscles, making sucking actions with the mouth, and bending fingers and toes. If you prod your belly, your baby will squirm, although you won't feel the movement just yet.

Why Do You Need a 12 Week Ultrasound?

This is the first chance to have your baby assessed for any developmental problems. If there are any issues detected, you'll need to see a fetal medicine consultant to confirm the findings, and assess how to proceed with the pregnancy. Early ultrasound allows parents to choose whether to continue with the pregnancy if any complications are detected. It's vital to take into account any clinical recommendations, as well as consider any religious, ethical, or personal beliefs you may have.

Here are some other reasons for an ultrasound:

• To confirm the pregnancy date. This is used to guess the due date.
• To see whether it is a multiple pregnancy.
• To assess for proper development of your baby. For example, the biparietal distance is calculated according to measurements of the fetus's skull, and is compared to those of other fetuses at similar gestation.
• To perform a risk assessment for Down syndrome by measuring the amount of fluid at the bottom of the fetus's neck. Ultrasound waves return echo-free measurements due to the space being translucent from the fluid.
• To detect your baby's heartbeat, which should be clearly heard at 12 weeks.
• To look at the fetus's size and placental development.
• To see if there are any physical abnormalities.
• To check for other issues by looking at your uterus, fallopian tubes, and general pelvic area.

Are There Any Disadvantages to an Ultrasound?

As long as it is conducted by a trained healthcare professional, the ultrasound scan is safe for both mother and baby. However, occasionally the scan shows a minor issue with the pregnancy. These problems normally get better by themselves, but can cause worry.

Remember, screening will always bring up some false positive and false negative results. For instance, the nuchal translucency scan, used to test for Down syndrome, has a 5% false positive rate; therefore one in twenty women who don't have a Down baby will be told incorrectly that their baby has a high risk of this condition.

Whether you have a scan is your choice and the sonographer will support you, whatever you decide. It is possible to have a dating scan without nuchal translucency screening. You can always change your mind the day you have the scan.

Now you know all about 12-week ultrasound!