Does the size of my bump matter?

For centuries, people have made guesses about a baby’s gender based on a pregnant woman's bump. They might say it’s a boy or a girl based on how it looks or sits.

The truth is that you can’t really tell much about the baby just from your bump. But that doesn’t mean it’s not important. Dr Donée van Rooyen, a gynaecologist and obstetrician at Mediclinic Cape Town, says that if you don’t have access to scans, your growing bump is the best way for your doctor to see how your pregnancy is progressing.

“The increasing size of your uterus lets us know how the baby is growing: the area from the base of your pubic bone to the top of your bump correlates more or less to how far along you are in your pregnancy, in terms of weeks,” she explains.

Your bump usually becomes visible around halfway through your second trimester, when it starts growing quickly (any bump before then is just pregnancy bloating). But if it doesn’t show up as expected, there are a few reasons why.

Dr Van Rooyen says genetics plays a role – if your mother carried a big bump, you might too. Your height also matters: taller women often have smaller bumps because their bodies are longer, so pregnancy weight is more spread out.

Shorter women, on the other hand, tend to carry more weight around their midsection, making the bump appear bigger. If you’ve been pregnant before, your muscles have already stretched, so your bump may be bigger. If you exercise regularly and have a strong core, your muscles will stretch later, making your bump smaller. Lastly, your baby’s position in the womb can also affect how big or small your bump looks.

The upshot is that there is no “right” or “wrong” way to carry. That said, Dr Van Rooyen warns that if your belly is much larger than usual, it could mean there’s more fluid around the baby than normal. This could be a sign of diabetes, as the extra fluid (from the placenta and baby’s urine) might happen if the baby is urinating a lot. It could also be linked to Down syndrome, where the extra fluid is caused by the baby having trouble swallowing. Your doctor will let you know if more tests are needed.

If you notice a sudden change in the size of your bump, let your doctor know right away. A sudden increase in size could mean the placenta has torn away from the uterus, while a decrease might mean your water has broken.

Otherwise, rest assured that your doctor is regularly checking on your baby’s health. Your bump – whether it’s high, low, small, or large – is more a matter of comfort than a sign of how well your baby is doing.