How Do Ultrasounds Work?

How Do Ultrasounds Work?

If you are pregnant, chances are you will have at least one ultrasound before your baby is born. Around 70 percent of pregnant women in the US will have an ultrasound. In the UK, this number is higher because ultrasounds are carried out as routine procedures for all pregnant women.

Ultrasounds are used to determine the size of your baby, the estimated due date, and whether the baby’s organs are developing well. If your healthcare provider considers your pregnancy to be high-risk, you may be offered more frequent ultrasounds to monitor the health of your developing baby.

How do ultrasounds work?

Ultrasound is a medical technique for creating images using high frequency sound waves and echoes. An ultrasound during pregnancy is used to give the sonographer a look at how the baby is developing inside your womb, and this may help to detect any problems.

If your scan takes place early in the pregnancy, you may be asked to attend the appointment with a full bladder. Having a large drink and then refraining from visiting the toilet can be easier said than done during pregnancy, but it’s important to get a good image of the baby. Early in the pregnancy, your uterus sits close to your bladder. A full bladder will push your uterus out of your pelvis, and allow the sonographer to get a better view.

When you arrive at your appointment, you will be asked to lie down on the examination bed. The sonographer will apply a cold gel to your bump, and then use a hand-held transducer across your stomach. If you are very early in the pregnancy, overweight or have a deep pelvis, your ultrasound may be carried out vaginally. In this instance, a vaginal probe will be inserted into your vagina to get a clear image of your baby. This will not harm your baby, but may be slightly uncomfortable for you.

The transducer, whether internal or external, will transmit millions of high-frequency sound pulses into your bump each second. The sound waves travel into your body and hit a boundary between tissues (for example, between bone and soft tissue) until they are eventually echoed back to the transducer.

The time difference between sound pulse and echo, is collected by the machine and this information is used to calculate the distance between the various boundaries inside your body. The ultrasound machine then displays this information as a two-dimensional diagram on the screen. This diagram shows the distances and strengths of the echoes received by the transducer, or in layman’s terms, it shows an image of your baby.

Are you having an ultrasound scan to check the development of your baby?

Written by Fiona, proud owner of a toddler, @fiona_peacock

This information is not intended to replace the advice of a trained medical doctor. Health & Parenting Ltd disclaims any liability for the decisions you make based on this information, which is provided to you on a general information basis only and not as a substitute for personalized medical advice. All contents copyright © Health & Parenting Ltd 2017. All rights reserved.