Baby measuring big for dates - what it really means

All it means is that doctors may want to monitor you and your baby more closely, and see if you need any tests.

How can they tell my baby's measuring big?

Your baby's size is checked by your midwife measuring your bump (called 'fundal height') during a check-up.

If they think you're measuring large for your dates, you'll likely be asked to go for what's known as a wellbeing or growth scan - or they may suggest some tests.

What the experts say about babies measuring big

Our resident GP, Dr Philippa Kaye (read more about Philippa on her dedicated website), tells us you may be checked for gestational diabetes if your baby's measuring large, as this could be a possible reason why.

(We know a few of our mums have had a couple of other blood tests to check various things, like thyroid function, after being told their baby's measuring big.)

There's NO need to be alarmed if you need these tests. They're just precautionary, to check there's nothing underlying going on.

Professor Basky Thilganathan, a Consultant Obstetrician and spokesperson for the RCOG, seems to agree, and stresses to us: "Most women who have a small baby or a large baby are having a healthy small baby or large baby."

He adds: "Bigger babies are very unlikely to have placental dysfunction. I think the major concern with bigger babies is: could it potentially lead to difficulties at birth?"

Yep, we're sure that thought's crossed your mind. Oh my gosh, is my baby going to be massive? Will I struggle to give birth, or even need a C-section?

Expert midwife/doula duo Beccy Hands and Alexis Stickland advise any woman who's found out her baby's measuring large not to worry.

"Your birth team will be keeping an eye on you," they note, "and if there are any concerns about babies’ size and the safety of a vaginal delivery, this will always be discussed and all birthing options will be presented to you – with you and the baby’s safety at the heart of all decisions."

Professor Basky also reassures us that there is no one 'big baby size' that's known to cause problems with a vaginal delivery or that definitely requires a C-section - because every pregnant woman's circumstances are different.

He also reckons the NHS is running a study at the mo to look at exactly this. (Of course, when that study is done - we'll update you here.)

"On the whole, the vast majority will have a perfectly healthy, straightforward pregnancy," Basky stresses again.

"These wellbeing scans are being done to reassure us that despite whatever risk factors [women] have, that their baby’s health is all going to be well.

"It’s a way for us to screen out, or pick up on, the few babies that may have a problem."

Anyway, just because you're 'measuring big', doesn't necessarily mean you'll go on to have a big baby!

It's well known that there's a margin of error (thought to be about 15%) between the measurements taken from midwives' fundal height checks and growth scans, and a baby's actual birth weight.

Dr Philippa also notes that if you're expecting twins or multiples, your bump will be a bit bigger - and therefore fundal height measurements won't be exact.

Women in our MadeForMums Community share their experiences of babies measuring big

MadeForMums Community member Anneka says, "At my 20 week scan he was off the charts, and I always measured around 3-4 weeks ahead of dates.

"In my case, it was just one of those things. They didn't induce me or discuss a C-section and I ended up going 5 days over and going into labour naturally.

"He was 10lb at birth so they were correct."

"I had this with my 2nd pregnancy," adds Linzi. "I was told that she would be well over 10lb.

"I was worried throughout my pregnancy as I wanted a natural birth and they kept on about a C-section. I was measuring weeks in front.

"She was born naturally the day before she was due and weighed in at 6lb 10oz so they are not always bang-on."

What MadeForMums says

We totally empathise with the fact that being told your baby's measuring big can cause lots of worry and panic.

However, any tests are just a precaution. If you do end up needing to discuss an induction or C-section, your docs will talk you through everything.

At the end of the day, it's better to know that your baby's being monitored closely, just to be safe. Try your best not to overly worry - we know it's tricky, but hang in there ?

Images: Stock image via Getty Images

Read more:

• Growth scans in pregnancy: what you need to know
• What does it mean if your baby's measuring too small?
• Scans and tests during pregnancy - what's coming?