Does your belly size fluctuate when pregnant?

Morning all! I am just now 21 weeks, and I started really showing about 3 weeks ago or so. I really thought that once I was 'showing', it would just keep getting bigger and bigger from then on. 

But this week it seems to have gotten a little smaller. My pants that didn't zip last week were fitting a little better this week. It's even easier to hide (not that I'm really trying to though)

Anyone else experiencing this?

Oh, and unrelated--am I the only one who rarely wakes up in the middle of the night to pee? Maybe once a week, but most nights I never get up. 

Here are 6 reasons that affect the size of your bump:

If it is your first pregnancy

If you are expecting your first baby, your stomach muscles are most likely still compact – making sure to hold your baby in. After your first baby the muscles have been stretched so they can expand more easily leading to a bigger looking bump. The bottom line is that there is no one size fits all when it comes to baby bumps.

The amount of amniotic fluid

The amount of amniotic fluid can fluctuate throughout pregnancy and even hourly. At the beginning of pregnancy your body is producing most of the amniotic fluid. However as your baby grows they are producing more fluid through urine and lung excretions meaning your bump may change in size.

Your height

If you are tall you will have a longer abdomen meaning your uterus will push upwards rather than outwards. If you are short, there is less room for your uterus between your hip and your lowest rib to grow upwards so it will push outwards instead making your bump appear bigger.

Baby’s position

Your baby will move around a lot during their time in the womb (as you probably know already if you are in the later stages of pregnancy)! As they near the end of pregnancy they usually prefer a head down position but they can move their backs from one side to the other and depending on their position your bump may fluctuate in size.

Space is getting tight

As your uterus expands with baby, the placenta and the cord there is less and less room. Your internal organs have to fit somewhere and depending on the way they move they may be hidden behind the uterus or to the sides. This will affect the shape of your bump.

Your baby’s actual size

Ok so your baby’s actual size will of course play a role! If both you and your partner are tall baby is more likely to be long. If you are both petite baby is less likely to be long.

The bottom line is that there is no one size fits all when it comes to baby bumps. So try not to worry or to compare yourself to other women. And always speak to your midwife or doctor to put your mind at ease if you are concerned.

Here at MFM HQ, we had to do a bit of a double take when mum-to-be Laura, from Dublin, share these 2 bump snaps with us – as they were taken ON THE SAME DAY.

Laura from Dublin, who is 16 weeks pregnant with her 3rd child, is amazed (as are we!) how much bigger her bump gets from morning (pic above, left) to evening (pic, above right).

"In the morning, I have a regular-sized bump," says Laura, "although it’s big for me as I was very small with my other 2. But, by the evening, I feel I look like I’m about to deliver – it expands so much!"

So, is it normal for your pregnancy bump get bigger at night?

We know, from the mums-to-be who chat on our forum and our Facebook page that Laura's smaller-in-the-morning-larger-at-night pregnancy bump is not a one-off – loads of others notice it, too.

On our forum, for example, Janebrown26 says: "I'm only 8 weeks 3 days with 2nd baby, and have a slight bump in morning – I can no longer fit it to my jeans. But, by bed time, I look like I'm 5/6 months."

And Sio39 has a similar experience at a much later pregnancy stage, saying: "For sure, mine gets bigger at nighttime. In the morning, it looks a lot smaller but by bedtime looks huge. I was 35 weeks yesterday."

Why does your bump look bigger at night?

So what's going on? Experts agree that it's all about your abdominal muscles getting tired from holding the weight of your baby bump, and so they loosen and expand, letting your bump sit out further and appear bigger. Then, when you go to sleep, those muscles get a chance to rest and recuperate, so, by morning, they’re refreshed and ready to hold your baby in more tightly again.

Quite how marked the daily small-to-large transformation is can depend on the number of pregnancies you have had, your build, and your age. Basically, your ab muscles may loosen a lot more easily and noticeably if you're over 35 and/or you've carried several pregnancies already – or carried multiples.

And then, of course, there are other more obvious that can play a part in the end-of-the-day bump swell: your baby may have changed position from the morning or you may have have downed a big meal in the evening – hello, pregnancy bloat!

More like this

So, all perfectly normal – if a bit of a surprise the first time you notice it! If you find your bigger evening bump uncomfortable, you may find wearing a maternity support band helpful.

What do you think?

Did your belly shrink and swell from day to night? Tell us in the comments below - or share some compare and contrast pics like Laura's on Facebook - we'd love to see.

Read more

Artem Varnitsin / EyeEmGetty Images

A mum-to-be is going viral on TikTok after sharing a video showing just how much her baby bump changes size throughout the day.

"Looks like I've skipped a whole trimester in a single day", the pregnant woman – whose username is @alanas.life – wrote in the caption of the clip. "So I'm halfway through my pregnancy", she added in another caption. "Let's see my morning vs evening baby bump."

In the clip, the mum-to-be then gives viewers a side-on look at her baby bump at 10am in the morning, followed by another look at midnight – and yep, her baby bump has got a lot bigger.

"Anyone else not realise this was even a thing before they got pregnant?? I just assumed your bump stayed the same size for the day hahaha", she wrote in the comment section, to which one TikToker replied: "I’m 17 weeks and I’m so glad to see this is normal! By the end of the day I have such a bump!"

"I'm only 10 weeks and my stomach looks flat in the am and then huge before bed," said another person on the social platform, with a third commenting: "By the end of the day I feel like I'm being stretched outwards."

This content is imported from TikTok. You may be able to find the same content in another format, or you may be able to find more information, at their web site.

With so much confusion as to why baby bumps change throughout the day, we spoke to Lesley Gilchrist, midwife and co-founder of My Expert Midwife, to find out more.

Why do baby bumps change size throughout the day?

"It is not uncommon for a woman to notice that her baby bump is looking bigger in the evening than it was in the morning," Lesley tells us. "This is generally due to the fact that her abdominal muscles, which hold the baby bump, have loosened and relaxed throughout the day, allowing the bump to 'push' further out and appear larger. The baby and the womb themselves have not changed size, though."

She went on, "Weaker or tired abdominal muscles may also lead to a more pronounced curve in the lower back, which can emphasise the larger appearance of the bump. After a restful night, the abdominal muscles have recovered and are stronger – and can therefore better hold the weight of the baby bump and the woman’s posture."

According to Lesley, there are a number of reasons why your baby bump might look bigger or smaller depending on the time of day. "In the morning, the stomach is empty and the digestive tract has digested all food from the night before, making the abdominal area and, thus, the baby bump, appear smaller than later on in the day, when we’ve ingested food – especially if it’s a big meal," she explains.

"Bloating can certainly make the baby bump appear larger and this is sometimes evident very early on in the pregnancy," the midwife adds, noting that, "Constipation is also an important culprit."

AsiaVisionGetty Images

And that's not all! "Baby’s position can also change the shape and size of the baby bump," Lesley points out. "For example, when a baby is head down, with their back towards the front of the bump, the latter tends to look quite round, neat and ‘compact’. But, if the baby is in a transverse position, with their body on horizontal and their head and feet at either side, the bump can appear considerably wider."

Is it normal for your baby bump to change size?

"It is common for women to notice some difference in the size of their baby bump from morning to evening, for all of the reasons explained above," Lesley tells us. "However, if a woman is concerned that their baby bump is not growing, or that it feels or appears too small for the stage of their pregnancy, she should contact her midwife or maternity unit for an assessment as soon as possible."

This article is not intended to be a substitute for professional medical advice or diagnosis. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.