2 minute read

Bump Measurements

This issue, the sisters discuss the size of your burgeoning bump.

Everyone seems obsessed by your bump when you’re pregnant. It always strikes us as baffling that no one would normally dare to comment on the size of your tummy but as soon as you’re pregnant, complete strangers feel the urge to comment on how big or small they deem your belly.

For some women though there’s no discernible bump for quite some time. Even at the 20-week scan, a few people worry that there should be a bump. We always advise women not to worry about the lack of a bump – you’ll have one soon enough. And in the same way that all of our bodies are different shapes and sizes when we’re not pregnant, our bumps are a host of different sizes when we’re pregnant.

Your midwife or doctor will start measuring your bump from around 28 weeks. It’s a rudimentary check performed with a tape measure, from the top of your uterus to your pubic bone, that’s done every time you see your midwife. Broadly speaking, the size in cm should correlate with the amount of weeks pregnant you are. It’s more about the trajectory though – some bumps just measure slightly smaller and some are slightly bigger. As long as the measurements are continuing along the same trajectory, there’s usually no cause for concern.

It’s worth remembering that this measurement is a bit subjective – different midwives can get different readings because of the way they’re measuring and because it’s using a simple tape measure, it’s not very accurate. Often you’ll get a more accurate reading if the measurement is done by the same person every time.

If there are any worries about the size of your bump, they would refer you for a scan and keep a closer eye on you. If your bump is measuring big, one of the risks is that you have gestational diabetes so they’d do a glucose tolerance test to check. They might also be concerned that you’re having an especially large baby, although a big bump doesn’t always mean a big baby. Remember there’s a lot of other stuff making up the bump other than the baby – there’s a sizeable placenta and plenty of amniotic fluid. If you’re a shorter person, your bump is likely to look larger by comparison than it might on a tall person.

If your bump is measuring small, it doesn’t necessarily mean that your baby is small. If you’re tall and have a long body, there’s more space within your body for your bump to hide, so your bump might look smaller from the outside. However if there are concerns that your baby is too small, your midwife will probably request a scan and for you to see an obstetrician to check that all is OK. The worry is that the placenta might not be functioning as well as it should and this could impact your baby’s growth. If, after scans and seeing an obstetrician, there were still concerns, they might suggest inducing labour early.

Seeing the number of pregnant women every week we do on The Bump Class, we know how much people worry about the size of their bump and how other people’s comments make them worry (even if their midwife has reassured them that nothing’s wrong). Our advice is to trust that you’re being well looked after.