An ultrasound scan (sonogram) transmits high-frequency sound waves through your womb (uterus). The sound waves bounce off your baby and are translated by a computer into an image on a screen, showing your baby's position and movements.
Your first scan is carried out at around 8-14 weeks and will give you the first glimpse of your baby. The main purpose of this scan is to check that your baby is growing and developing normally, and to work out the estimated date of delivery (EDD).
Finding out your baby's sex
The second scan is carried out at around 18-21 weeks, and its main purpose is to check for any structural abnormalities (anomalies) in the baby. If you want to find out the sex of your baby, you can usually do so during this scan.
If you want to know your baby's sex, you should ask the sonographer (the person who carries out the scan) at the start of the scan, so they know that they need to check.
You should be aware that it's not possible for the sonographer to be 100% certain about your baby's sex. For example, if your baby is lying in an awkward position, it may be difficult or impossible to tell whether your baby is male or female.
Some hospitals have a policy of not telling patients the sex of their baby. If your hospital does not routinely inform parents about their baby's sex, you may be able to pay privately for a scan to find out. Speak to your sonographer or midwife to find out more.
See the pregnancy and baby guide to find out how your baby is growing and developing, and for advice on how to keep healthy throughout every stage of your pregnancy.
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