Seven Year Switch's Cassie: "This pic was never meant to be public."

Seven Year Switch star Cassie has posted an emotional message on Instagram, detailing the criticism she faced during her fourth pregnancy.

The reality star – who recently welcomed her fourth baby, Mena – says she faced constant comments from strangers about her ‘large’ baby bump.

"I carry big and all out the front! Because of this comments are made from as early as 20 weeks to the tune of, 'Oh u must be nearly due', or 'Are you sure there isn't twins in there', or 'Are you sure everything is ok? Your baby is going to be so big!" she wrote.

Her message was accompanied by a photo that Cass says was "never meant to be shared in the public eye". She is posing in her underwear, taking a selfie of her baby bump at 35 weeks.

Cassie says she was inspired to share her story after hearing about another women who faced judgement from others about the size of her baby bump.

Night night Insta... Love Us and our gorgeous niece ????????????❤️ #sevenyearswitch #ryanandcassie #babybump #family #inlove #happiness #bigmumma #ohwhataday #pregnancy #myhusbandishot #blessed ✌️

A photo posted by Ryan And Cass (@ryanandcass) on May 28, 2016 at 3:57am PDT

"I felt compelled to put all my insecurities aside and share my bare bump in support of this amazing Mum," she wrte. "Throughout all of my pregnancies I have shown from as early as 5 weeks pregnant. My uterus sits forward which makes for no hiding anything. "The kind of pressure on pregnant women or women in general is NOT OK! Pregnancy and women need to be celebrated NOT ridiculed! What we do is a damn miracle...we create LIFE!"

That first night home is always the hardest! Sleep tally Mon - Sat is at about 18 hours in total... That pregnancy glow has well and truly gone lol! Hence capturing a beautiful moment in this beautiful filter this morning was essential! Happy Saturday everyone! Enjoy whatever it is that makes you smile❣ #sevenyearswitch #ryanandcass #newborn #instababy #family #newborn #love #menalee #4daysold #whatpregnancyglow #nosleep #picoftheday ???????? A photo posted by Ryan And Cass (@ryanandcass) on Jun 17, 2016 at 4:23pm PDT

Cassie announced she was pregnant during the reunion episode of Seven Year Switch, revealing her and Ryan had decided to stay together.

They welcomed daughter Mena Lee one month ago.

The couple are already parents to Cassie's ten-year-old daughter, Ramani, from a previous relationship, 19-month-old daughter Emmerson and a son, Dex, who was stillborn.

Watch Seven Year Switch's Ryan and Cassie reunite for the first time after being apart.