Monitoring your baby’s heartbeat: CTG and Doppler

If your baby needs checking, you may be offered a CTG. Here’s what it is, why it’s used, and why you shouldn’t rely on a home heartbeat monitor.

What is a CTG?

A CTG, or cardiotocograph, is a recording of your baby’s heartbeat. A St George’s hospital trust page describes it as a continuous electronic recording that usually uses two discs on your tummy: one picks up your baby’s heart rate using ultrasound, and the other detects contractions. It can last between 20 minutes and several hours, depending on why it’s needed.

When might you have one in pregnancy?

The trust says a CTG may be recommended if you come in with a complication, and examples include your waters breaking, tummy pain if you are under 37 weeks, vaginal bleeding and reduced movements. For that trust, this applies over 26 weeks of pregnancy, and the threshold may differ in other areas. If your baby is moving less, call straight away.

If your baby’s movements slow down, stop or change, call your midwife or maternity unit straight away, day or night. Don’t wait until the next day, and don’t use a home Doppler to check the heartbeat, because it isn’t reliable.

Listening to your baby in labour

In a low-risk labour, the trust describes intermittent auscultation, which is listening with a handheld Doppler or Pinard stethoscope at set times, as the recommended way to listen at 37 to 41 weeks and 6 days. It says continuous CTG monitoring is recommended if you have an induction of labour or an epidural. Without any known risk factors, the trust notes a CTG may lead to more interventions than intermittent listening. This is one to talk through with your midwife in your birth plan, and the trust’s guidance may differ from your own.

Home heartbeat monitors and apps

The NHS is clear: do not use a home Doppler (heartbeat listening kit) to try to check your baby’s heartbeat yourself. It says this is not a reliable way to check your baby’s health, and that even if you hear a heartbeat, it does not mean your baby is well. Midwives do use a handheld Doppler or Pinard stethoscope in clinic and labour. This is different from a home heartbeat kit you buy yourself. If something feels different, call your midwife or maternity unit instead.

What if a CTG looks different from expected?

A CTG reading can look different for many reasons. The St George’s page doesn’t explain specific readings, so ask your midwife or doctor what they are seeing and what the plan is. You’re allowed to ask questions at any point.

Questions people ask

Is a CTG painful?

It shouldn’t hurt. Two discs sit on your tummy, held by bands. Tell your midwife if you are uncomfortable.

Can I move around during a CTG?

It depends on the equipment. The trust page says a wireless monitor is available but isn’t in every room, so ask your team.

Is a home Doppler safe to use?

The NHS says not to use one to check your baby’s heartbeat, because it isn’t a reliable way to check your baby’s health.

How do I know if my baby’s movements are normal?

You know your baby’s pattern best. See your baby’s first movements, and call straight away if their movements change.