Is my bump (or belly) too small or too big?

The RCOG says the size of your bump, called the symphysis fundal height, is measured from 24 weeks at each appointment and plotted on a chart. The NHS schedule lists bump checks at 25 and 31 weeks in a first pregnancy, and at 28, 34, 36, 38, 40 and 41 weeks.

If growth slows or your baby may be small, you’ll be offered an extra ultrasound scan, often called a growth scan. A baby is called small, or small for gestational age, if their estimated weight is below the 10th centile, meaning the lowest 10 in every 100.

The RCOG says many small babies have no health issues. If your baby is small, it says birth is advised by 39 to 40 weeks at the latest.

The pages we read don’t set out what happens if a bump measures large, so ask your midwife or doctor. Gestational diabetes is one known reason for a larger baby.

You can contact your maternity team at any time if you’re worried. Whatever your bump looks like, call immediately if your baby’s movements have reduced or changed. The RCOG says to go straight to hospital if movements are reduced in a small baby.

The RCOG lists risk factors including being 40 or over, a BMI below 18.5, smoking, more than 200 mg of caffeine a day, high blood pressure, diabetes and a previous small baby. If you’re at higher risk, you may be advised to take 150 mg of aspirin from 12 to 36 weeks. Don’t start it yourself.