When Rhianna Swan went to hospital with stomach cramps, she did not expect to be giving birth two hours later — because she had no idea she was pregnant.
The Adelaide mother, who was diagnosed with endometriosis from a young age, told ABC Radio Adelaide she did not experience any symptoms of pregnancy.
On the day of the birth, the 41-year-old went to Queen Elizabeth Hospital with abdominal pain, which she said was not unusual in itself, but had become worse.
“They got the ultrasound machine out and scanned over my stomach and found a heartbeat,” Ms Swan said.
“From there it was shock, disbelief, a few profanities said out loud by myself and my husband as well.
“And then as they looked further down with the ultrasound machine, they said, ‘The head’s right there, you’re ready to go.'”
Rhianna Swan gave birth to baby Caleb unexpectedly. (Supplied: Rhianna Swan)
She said she ended up having an emergency caesarean after she tried pushing but could not get the baby out.
Ms Swan and husband Jason welcomed baby Caleb on June 21.
But not only did Ms Swan have no suspicion she was pregnant — she said she had previously been told it would be “unlikely or very difficult” for her to conceive a child.
“I was wearing the same work pants that felt comfortable,” she said.
“I looked a little bit more bloated … [but] everything was normal.
“We were in Queensland the second week of May, we went to Dreamworld so we were on the roller coasters, going out for dinners, drinking, doing all the things you would normally do on a holiday, just having fun [and] enjoying some time away.
“Came back, got tattooed — all the things you shouldn’t do when you’re pregnant I did because I was totally unaware.”
Rhianna Swan said she did not have signs of pregnancy. (Supplied: Rhianna Swan)
Ms Swan said their family and friends were in “utter disbelief” but soon banded together to help the couple out with their new arrival.
“We’re still getting it now from people, ‘What? When did you have this? What happened?'”
Cryptic pregnancies not ‘uncommon’
Obstetrician and gynaecologist John Svigos said what are medically known as cryptic pregnancies — where a woman is unaware until late into gestation — are more common than many people might suspect.
“It’s not an uncommon story to hear from obstetricians, particularly years ago when ultrasounds and other things weren’t available,” the associate professor said.
“[Some people might] just think, ‘I’ve put on a bit of weight.'”
But partly because they cause such surprise to parents, cryptic pregnancies often yield striking stories — such as a recent case in Tasmania, in which a baby was born into a toilet.
Dr Svigos said they might occur in as many as one in 500 pregnancies, but he said cases like Ms Swan’s, in which mothers “roll up fully dilated, ready to have a baby”, are much rarer.
“I think it’s probably rarer nowadays because ultrasounds are done very quickly and easily,” Dr Svigos said.
He said some women who have irregular menstrual cycles or do not have periods may not realise they are pregnant — with some almost in “denial”.
“Until you put the foetal heart monitor on and they can hear the foetal heart, they still won’t believe you,” Dr Svigos said.
“It’s not until you deliver the baby that they believe — that’s how strong the process of denial can be.”
Dr Svigos said such a birth could be “a shocking experience” for new mothers but “it’s papered over really by the wondrous arrival of the baby that they haven’t been expecting”.
But he said one thing to be aware of was the fact that cryptic pregnancy could impact mothers “from a mental health point of view”, especially if such pregnancies were unplanned or could “create estrangement within the family”.
“Sometimes it occurs in people desperate to have a baby, sometimes it occurs in people desperate to not have a baby,” he said.
Associate Professor John Svigos says he has encountered several cryptic pregnancies in his career as an obstetrician. (ABC News)
Dr Svigos said that, based on his experience and from speaking with other obstetricians, the babies are usually born “fantastically healthy”.
In her case, Ms Swan said Caleb’s health was her biggest concern at the time of the birth — but “he’s come out perfect”.
“Hearing’s fantastic, he’s growing really well, feeding well, sleeping well.”