If only MP Jo Swinson had spotted Mamma On The Move before standing up up Prime Minister's Questions last week. The online company sells a combination of t-shirts and bags that notify the world: "Yes, that's a baby in there, not a Krispy Kreme."
After debate kicked off last week - none of the surrounding MPs offered Swinson a seat - around people discussing whether it would be 'sexist' to offer a (pregnant) woman a seat, the conclusion was: of course not.
However, there is no getting around the rather awkward issue of deciding whether a woman is overweight or pregnant.
Offering a nice alternative to the Baby On Board badges, businesswoman Giulia Iannuci set up the company last year after her first baby was born.
She said: "During the pregnancy I had to commute every day on the train and getting a seat was close to impossible. Some people pretended not too see the belly, others probably weren't sure if I was pregnant or not (at the beginning). So after my son was born I decided to create t-shirts and bags that pregnant women could wear or carry on public transport to help them get a seat."
Do they actually work? "I carried my "Reserved seat" bag (see below) during my second pregnancy and almost every time someone gave up their seat without me having to ask... it was just question of making sure that the bag was right in front of them!"
Some people might claim that they don't even notice what's going on because they're too absorbed reading or playing with their phone.
To that, Giulia says: "The excuse of not seeing a belly is a bit weak for me. Before I had my bag I have been left standing up even when I was 8 months pregnant with a HUGE belly, so I'm not quite sure how someone could have missed that.
"However, I agree that sometimes it's not that easy to understand if a woman is a bit overweight or at the first stage of a pregnancy but there is a very easy way to find out without risking to offend her: simply stand up, if she is pregnant she will go for the seat. And yes you might have lost your seat for nothing (I doubt it) but if she was pregnant you would really have made her day, with a very simple gesture."