In 1990, a 30-year-old woman reported to the hospital at the University of Nebraska College of Medicine with all the signs of being a few months pregnant, complete with an enlarged belly. However, when an ultrasound was subsequently performed, it was discovered that the woman had no uterus or cervix. She had undergone a hysterectomy two years previously, and while she was fully aware that it was impossible for her to be pregnant, her stomach had still swollen up like she was pregnant and she believed she was going to give birth.

This was a case of a condition called pseudocyesis, or false pregnancy. Pseudocyesis has been reported to occur in between 1 and 6 out of 22,000 births (however, other sources have suggested that the incidence is likely much higher in developing nations). A total of only 80 cases were reported in medical literature between 2000 and 2014. It is very difficult to research beyond reporting single case studies because it so rare and often goes undetected until the condition has been present for a while and the patient believes they are in labor.

The symptoms include all those of a typical pregnancy: weight gain, growing belly, morning sickness, interrupted periods, cravings, and even sensations of the baby moving and kicking, making it extremely difficult to diagnose. Additionally, most cases occur in married women who have been trying to conceive for years, making the false pregnancy even more convincing and difficult to detect.

Due to the difficulties associated with studying the condition, what causes pseudocyesis is still relatively unknown, although there are a number of theories. Some researchers believe it is physical while others suggest it stems from psychological issues, and still others emphasize the impact of social and cultural factors. It is likely that there are a variety of different factors that can cause it and many times multiple components are involved.

Some evidence suggests potential causes that are purely physical. For example, certain ovarian tumors have also been found to have the ability to cause pseudocyesis. Another important physical influence is related to hormones. Some research suggests that women who present with false pregnancies may have increased sympathetic nervous system activity and dysfunction of pathways involved in regulation of hormone secretion, specifically those involved in reproduction and pregnancy. Additional evidence comes from the fact that false pregnancy can also occur in other animals. Dogs in particular are especially prone to pseudocyesis. Neutered females or females mated with infertile males can show signs of pregnancy after mating, and this effect is believed to be caused by abnormally high levels of reproductive hormones when the female is in heat, further suggesting the powerful role of hormonal changes on the body.

However, there is evidence to contradict the idea that pseudocyesis is purely hormonal – even some men have been found to exhibit symptoms of false pregnancy. In men, it most often occurs when their partner is pregnant and is known as sympathetic pregnancy. While these men are perfectly aware that men cannot get pregnant, an overly emphatic response to their partner’s pregnancy can result in weight gain and back aches similar to what their partner is experiencing.

There are many psychological factors that have been shown to be extremely impactful for the development of pseudocyesis. 80 percent of false pregnancies have been observed to occur in married women, and 37 percent have been pregnant at least once, suggesting the influence of social expectations or personal desires to have children. One theory suggests that an extremely strong desire for or fear of pregnancy causes elevated levels of internal conflict and stress which can result in the hormonal changes that cause false symptoms of pregnancy to occur. In particular, the emotional stress and trauma that can come with miscarriages, infertility or the loss of a child might also increase the risk of developing pseudocyesis. There are additional theories suggesting that major depressive disorder might also be involved in the associated hormonal changes.

It is important to note that pseudocyesis is not caused by a woman consciously wanting a child so badly that she somehow “convinces her body” that she is pregnant. Women who experience false pregnancies often truly believe that they are pregnant, but this is not a delusion, because their bodies feel and look as if they are truly pregnant and it can be difficult even for trained doctors to tell the difference. One researcher describes false pregnancy as a physical, emotional and societal illness, much like anorexia nervosa. Both disorders are influenced by extremely harmful social pressures, and the emotional distress that can come from not being able to conform to these pressures eventually leads to physical manifestations.

Social and cultural factors have also more recently been discovered to play an immensely important role. As discussed previously, extreme emotions and stress surrounding pregnancy, childbearing, and infertility can have powerful effects on hormones and the body. Consequently, pseudocyesis has been observed to be much more common in developing countries where childbearing is often seen as an extremely important part of a woman’s role in society and immense pressure is put on women to have children, especially sons. Additionally, the blame for infertility is most often placed on women in these countries, furthering the stress around pregnancy, especially for women who are experiencing difficulty or inability conceiving with their partners. While a commonly cited study conducted in Boston hospitals in the US reported pseudocyesis as being extremely rare and occurring in only 1/22000 births, research in various African countries has found much higher rates. For example, 1 out of every 344 newly booked expectant mother at a hospital in Nigeria were found to exhibit pseudocyesis.

Pseudocyesis is a fascinating example of how much of an influence the brain can have over the body, and how social, biological and psychological factors can be extremely important for this as well. It is amazing to realize that thoughts and emotions in the brain can have such a dramatic effect on the body that it can respond with all the very real physical symptoms of pregnancy even in the absence of a fetus. The phenomenon of false pregnancy serves as a powerful reminder that the brain and body are extremely interconnected and that mental health can impact your body as much as physical health.

Sources:

Azizi, M., & Elyasi, F. (2017). Biopsychosocial view to pseudocyesis: A narrative review. International Journal of Reproductive BioMedicine, 15(9), 535.

Oksman, O. (2017, October 20). ‘Phantom Pregnancy’ Is One of the Most Bizarre Medical Mysteries. Retrieved from https://www.vice.com/en_us/article/59ymj5/phantom-pregnancy-is-one-of-the-most-bizarre-medical-mysteries

Paulman, P. M., & Sadat, A. (1990). Pseudocyesis. Journal of Family Practice, 30(5), 575-577.

Svoboda, E. (2006). „All the Signs of Pregnancy Except One: A Baby‟. The New York Times, 5.

Tarín, J. J., Hermenegildo, C., García-Pérez, M. A., & Cano, A. (2013). Endocrinology and physiology of pseudocyesis. Reproductive Biology and Endocrinology, 11(1), 39.

Cover image source: https://www.huffpost.com/entry/pseudocyesis-false-phantom-pregnancy_n_5037887