Your Baby Bump: How Do You Measure Up?

by Joshua Calton-Weekes |

Bumps come in all shapes and sizes. But that doesn’t stop you panicking – especially if you’re told you’re small for dates.

Bumps can be pretty tricky to get your head around. For the first time you can remember, you’re happy to see your belly get bigger. That said, you’ve probably never put so much attention on the exact size and dimensions of your abdomen either. And never before have you wanted your belly to be big enough.

How is your bump measured?

In early pregnancy it’s a bit of a ‘has it popped yet?’ scenario most days. But once you reach 16 weeks, chances are your bump will be beginning to form. Laying on the couch in the midwife’s office while she presses and prods your bump is all for a good cause as it helps to assess the size and position of your baby.

‘The size of the baby is measured by physical examination of your uterine size and growth at your antenatal appointments,’ explains Teresa Walsh, midwife at The Portland Hospital, London. ‘The size of the uterus is measured from the fundus (top) to the pubic bone. Ultrasound scans are also used to assess fetal growth.’

What does it mean if your bump is measuring small for dates?

The biggest concern if your unborn baby is measuring small for your dates is whether he is developing how he should be.

The risk, although slight, is that the smaller than expected bump for your dates could be a sign of a problem with your placenta, such as that would need immediate investigation and treatment.

Your bump is measured is against an average, so often if your bump size doesn’t match this it isn’t cause for concern and could be as simple as your baby will have a growth spurt in the coming weeks and catch up. It can also mean that all those stomach crunches you have done over the years have paid off and you have really strong abdominal muscles that mean you carry your baby slightly different to the average woman.

What if the midwife says your baby is too small for dates?

If there is a chance the size of your baby may be related to your placenta not working correctly, or any other concerns, your midwife will refer you for further examination. The most likely next stage would be an ultrasound. This is a good way to better date your pregnancy and to try and identify the cause of your bump being smaller than expected.

What causes your baby to be too small for your dates?

There’s no one reason to explain what causes your baby to be small for your dates but factors can include an issue with your placenta (as mentioned above), or that your dates of your pregnancy aren’t quite right, or could even be related to lifestyle choices including smoking and drinking alcohol in your pregnancy.

‘Smoking and drinking alcohol during pregnancy are common causes for small babies. On some occasions it can be genetic or it could be a sign of your placenta not working efficiently’, says Teresa.

Does it mean your baby will be born small?

Some babies will catch up and be born at an average weight but this isn’t always the case.

‘Some babies will remain small for their dates but be healthy through the pregnancy and be born small. Other babies can need to be born early and will have support after their birth to gain more weight,’ says Teresa.

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