When she was pregnant with her twins, Beyonce had to deny that she'd had lip fillers while pregnant after sharing a photo on Instagram of herself complete with baby bump and oh-so-fulsome lips.
At the time, her rep explained that the pop icon had not had any kind of lip enhancement - but that her new, fuller lips were one of the symptoms of her pregnancy.
Here at MFM HQ, we went on to hear mentions of pregnancy lips from other expectant stars, too.
So, are pregnancy lips something that really can happen? Here's what you need to know...
Celebs share their 'pregnancy pouts'
Jacqueline Jossa, who is expecting her 2nd baby, seemed surprised when her lips started to plump up.
She wrote beside a picture of her fuller lips: "The pout on that!! Jeeez!! Sometimes through this pregnancy I think my lips must be swollen they seem bigger than usual!
"Also feeling more tired this week!! Taking it out of me! 4d scan tomorrow which is always exciting!! (Someone tell me face)"
Meanwhile, tennis ace Serena Williams, now mum to baby Alexis Olympia, told her Instagram fans in a story that she'd actually been WAITING for her lips to swell while she was pregnant.
She posted excitedly: "Pregnancy lips are finally here! I'm SOOOOO excited! LOL haha".
Celeb mum Amy Childs also confessed to noticing a fullness in her lips while she was pregnant with her daughter, Polly.
So, it would seem then that they definitely are a thing - but what do they experts say?
Can lips really swell or appear fuller during pregnancy?
Gail Johnson, Education Advisor at the Royal College of Midwives, told MFM exclusively:
“During pregnancy the action of hormones means that blood vessels dilate more which can mean that the body retains more fluid in the tissues during pregnancy.
"This is often most common in the lower limbs, but can also happen elsewhere for example the fingers, the face and sometimes the lips.
"The lips have good surface blood vessels network which give the lips their colour and also are sensitive due to many nerve endings.
"The pregnancy hormones both increase the volume of blood circulating and relax blood vessels so they are fuller. In addition oestrogen keeps the fullness of lips and of course this hormone is gradually increased all through the pregnancy."
Are fuller lips in pregnancy something to worry about?
Right, so, pregnancy lips are totally a thing... but should you panic? Definitely not, says Gail.
“If this happens women should not be worried, as it will generally settle down by itself," she tells us.
So, swelling in the lips is generally nothing to worry about, but Gail does gives us a good reminder to watch out for swelling in other areas.
"If women do have swelling in their limbs they can take some simple actions to reduce the swelling such as keep cool, avoiding standing for long periods and put their feet up as much as possible," she says.
“While women should not worry about swelling in pregnancy, it could be a sign of pre-eclampsia although it is important to note that most women with swelling don't have pre-eclampsia.
"If the swelling occurs suddenly and is not relieved by rest or is accompanied by symptoms such as severe headache, problems with vision, severe pain below the ribs or vomiting, then it could be pre-eclampsia and women should contact their midwife or doctor immediately."
There you have it. Pregnancy lips, it seems, are just another one of those strange symptoms you can get when you're expecting.
A bit how your like your hair can change or that funny metallic taste so many of us get in our mouths - they are, simply put, just one more of the odd things our body does when it's growing a little human inside it ?
Images: Stock shot/Serena Williams on Snapchat
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