Pregnancy scans: what are they looking for?

Lying on the couch with cold gel on your tummy, watching a grey screen and trying to read the sonographer's face: scan days can hold excitement and nerves in the same breath. Here are the questions mums ask most, answered simply.

What is a pregnancy scan?

A pregnancy scan, or ultrasound, uses sound waves to create a picture of your baby, your womb and the placenta. It has been used in pregnancy for decades and is considered safe. A sonographer or doctor moves a small probe over your tummy. Early in pregnancy, a scan is sometimes done internally, through the vagina, because it gives a clearer view. It may feel a little uncomfortable but should not hurt. You can always ask them to pause.

Which scans will I be offered?

The exact schedule depends on where you live and your health, but many mums are offered two main scans.

The early or dating scan

Often done somewhere between about 10 and 14 weeks. It usually:

• Confirms that your baby has a heartbeat.
• Measures your baby to estimate how many weeks pregnant you are and give a due date.
• Shows whether you are expecting one baby or more.
• May be combined with screening for some conditions, if you choose it.

The mid-pregnancy or anomaly scan

Often done somewhere between about 18 and 21 weeks. It is a careful look at how your baby is developing, including:

• Your baby's head, spine, heart, tummy, kidneys and limbs.
• Your baby's growth.
• Where the placenta is lying.
• The amount of fluid around your baby.

This scan cannot find every condition, and most babies are found to be developing well. If something needs a closer look, you will be told and offered more support.

Extra scans

Some mums are offered more scans later in pregnancy, for example to check growth, the position of the placenta, or if you are expecting twins or have a health condition. An extra scan is a sign of careful care, not automatically a sign of trouble.

Is screening the same as a scan?

Not quite. Screening tests estimate the chance that a baby has a particular condition; they do not give a definite answer. Some screening uses a scan measurement together with a blood test. Screening is your choice. Your midwife or doctor should explain what is offered, what the results mean and what would happen next, so you can decide what feels right for your family. It is fine to take time, pray and talk it through before deciding.

How do I prepare?

• Check your letter: some early scans ask you to have a fairly full bladder, which helps the picture.
• Wear something easy, such as a top with trousers or a skirt, so your tummy is easy to reach.
• Ask whether you can bring someone with you, and whether children are allowed.
• If you would like a printed picture, ask beforehand whether there is a charge.
• Write down any questions, such as 'Can you show me the heartbeat?'

Why is the sonographer so quiet?

They are concentrating hard. Measuring a wriggling baby takes focus, and they often finish all their checks before saying much. A silent sonographer is usually just a busy one. If you feel anxious, it is perfectly fine to say, 'I'm nervous. Could you tell me what you're looking at?'

What if I am asked to come back?

This happens often. Babies lie in awkward positions, and a full view of everything is not always possible on the day. Being called back for another look is common and frequently turns out to be because the picture was simply unclear. If they want to look more closely at something specific, ask:

• What exactly are you checking?
• When will I know more?
• Who can I call with questions before then?

When scans bring hard news

Some readers have walked out of a scan room with news that changed everything. If that is you, or it becomes you, please know you are not alone and nothing you did caused it. Ask for a quiet room, take someone with you to any follow-up appointments, and lean on the specialist midwives and counsellors your hospital can offer. Grief and questions are both allowed.

Seen before you were born

The psalmist marvels at being formed by God, and says, “I am fearfully and wonderfully made: marvellous are thy works” (Psalm 139:14). Long before any screen showed your baby's shape, God knew every detail. The scan is a gift that lets you glimpse a little of what He already sees.

If you notice bleeding, pain or fewer movements in the days after a scan, do not wait for results letters. Call your midwife or maternity unit.

A prayer for scan day

Father, You see my baby more clearly than any screen ever could. Calm my racing heart as I lie on that couch. Guide the hands and eyes of those who scan me, and whatever we see today, hold us both close. Amen.