Rare 'phantom' condition leads people to show symptoms of pregnancy with no fetus

There's an extremely rare condition that makes people believe they're pregnant when they're not.

Usually, when a person starts presenting symptoms of something, it means they have it. For example, if your nose started running, you had a sore throat, and you developed a cough, there's a good chance you've developed a common cold.

But things are always as linear as this, as anyone who's had pseudocyesis would tell you.

Pseudocyesis (which is sometimes referred to as a phantom pregnancy) is an extremely rare condition that only affects around six in every 22,000 births in the US, per a 2007 review in the International Journal of Reproductive BioMedicine.

But what is pseudocyesis exactly? Here, we break down what the extremely rare condition is and its symptoms.

There are around six cases of pseudocyesis per 22,000 births (David Zorrakino/Europa Press via Getty Images)

What is pseudocyesis?

According to the Cleveland Clinic, this condition is when somebody thinks they are pregnant because they have pregnancy symptoms and feel as if they're carrying a child, when actually they're not.

It's reported that most cases occur in patients aged 16-39 years.

Pseudocyesis was more common before the creation of reliable pregnancy tests. The key difference between pseudocyesis and a real pregnancy is the absence of a fetus in the womb.

Symptoms of pseudocyesis

Symptoms of the condition are very similar to pregnancy, which is why it can lead people to believe they're carrying a child.

Cleveland Clinic lists the following signs to look out for:

• Breast tenderness
• Enlarged abdomen
• Missed menstrual period
• Weight gain
• Nausea or morning sickness
• Food cravings or aversions
• False labor contractions

A public figure who's reported to have had at least one phantom pregnancy is Queen Mary I of England in 1555.

Mary I of England reportedly experienced the very rare phenomenon (Fine Art Images/Heritage Images/Getty Images)

She was 38 at the time, according to National Geographic, and her apparent pregnancy occurred a year after she married Philip II of Spain.

Queen Mary looked pregnant and was experiencing many pregnancy-related symptoms, but sadly, the baby she thought she was carrying never came, as it was later revealed that she had pseudocyesis.

Reportedly, this is history's first well-documented case of a rare phenomenon.

Difference between phantom pregnancy and delusion of pregnancy

Writing for News Medical, Dr. Liji Thomas, a medical doctor specializing in obstetrics and gynaecology, said: "Phantom pregnancy is different from a delusion of pregnancy.

"The latter occurs in mentally unstable women, as part of their psychotic symptoms.

"The fixed false belief that the woman is pregnant remains despite all reasoning and evidence to the latter. There are no physical changes similar to those that occur in a pregnant woman either."