The nausea, the fatigue, the swelling breasts … It’s usually easy to see that those pregnancy symptoms add up to, well, a pregnancy. But in rare instances, that’s not the case.

A false pregnancy is also known as a phantom pregnancy, or by the clinical term pseudocyesis. It’s an uncommon condition that causes a woman to believe she’s pregnant. She’ll even have many classic symptoms of pregnancy.

But this isn’t related to a miscarriage. In a false pregnancy, there was no conception and there is no baby. Despite this, symptoms can last long enough to make a woman, and even those around her, believe she’s expecting.

At this time, there’s no answer to why some women experience pseudocyesis. But there are three leading theories. Some mental health professionals believe it’s related to an intense desire or fear of becoming pregnant. It’s possible that this affects the endocrine system, which in turn causes symptoms of pregnancy.

Another theory relates to wish fulfillment. Some mental health professionals believe that when a woman yearns to be pregnant, possibly after experiencing multiple miscarriages, infertility, or because she wants to get married, she may misinterpret certain changes in her body as a clear sign that she’s pregnant.

The third theory is related to certain chemical changes in the nervous system that are related to depressive disorders. It’s possible that these chemical changes are responsible for the symptoms of false pregnancy.

A false pregnancy often resembles pregnancy in every way, minus the presence of a baby. In all cases, the woman is absolutely certain that she is pregnant.

Physically, the most common symptom is a distended abdomen, similar to a baby bump. The belly can begin to expand just as it does during pregnancy when a developing baby grows. During a false pregnancy, this abdominal extension isn’t the result of a baby. Instead, it’s believed to be caused by a buildup of:

  • gas
  • fat
  • feces
  • urine

Irregularity of a woman’s menstrual cycle is the second most common physical symptom. Between one-half and three-quarters of women experiencing pseudocyesis reported feeling the baby move. Many women also report feeling the baby kick, even though there was never a baby present.

Other symptoms can be just as difficult to distinguish from those experienced during an actual pregnancy, and can include:

  • morning sickness and vomiting
  • tender breasts
  • changes to the breasts, including size and pigmentation
  • lactation
  • weight gain
  • labor pains
  • inverted bellybutton
  • increased appetite
  • enlargement of the uterus
  • softening of the cervix
  • false labor

These symptoms can be so believable that doctors can even be deceived.

Showing a woman proof that she really isn’t pregnant through imaging techniques like an ultrasound is the most successful way to bring a false pregnancy to an end.

False pregnancies aren’t thought to have direct physical causes, so there are no general recommendations for treating them with medication. But if a woman is experiencing symptoms like menstrual irregularity, medication may be prescribed.

False pregnancies seem to disproportionately take place in women experiencing psychological instability. For that reason, they should be under the care of a psychotherapist for treatment.

The concept of a false pregnancy is nothing new. Hippocrates is credited for the first written account in 300 B.C. Mary Tudor is a famous historical example. Instances of pseudocyesis have dropped significantly in the United States over the last century.

In the 1940s, cases of false pregnancy occurred in approximately 1 out of every 250 pregnancies. That number has declined to between 1 and 6 cases for every 22,000 births.

The average age of a woman experiencing a phantom pregnancy is 33. But there have been cases reported in children as young as 6 and women as old as 79. Roughly one-third of women with pseudoscyesis have been pregnant at least once before, and more than two-thirds are married. Women who have experienced incest could be at a greater risk of experiencing false pregnancies.

In countries with easy access to accurate pregnancy tests, false pregnancies have become quite rare. Some cultures link a woman’s worth with her ability to conceive, and pseudocyesis is seen in higher rates in these parts of the world.

It’s rare to experience a false pregnancy. Symptoms of pregnancy and pseudocyesis may be confusingly similar, but there is one significant distinction. In a false pregnancy, there is simply no baby. That’s because no conception ever took place, despite symptoms that seem to suggest otherwise. See your doctor if you have questions or think you might be pregnant.