By Victoria Stern, published on January 1, 2009 - last reviewed on December 22, 2009
A teenage girl entered the emergency room with her mother, complaining of unexplainable and excruciating stomach pains. Then she gave birth. Both the teenager and her mother claimed they had no idea about the pregnancy before the delivery.
"I briefly interviewed this young woman and her family after the incident," says Nada Stotland, a professor of psychiatry and Ob/Gyn at Rush Medical College. "They seemed nice enough"—like a normal, healthy family. The teenager suffered from "denial of pregnancy"—a mysterious and rare disorder where a woman does not know she's pregnant until at least five months into gestation. Doctors estimate the prevalence at about one case per 200 to 600 deliveries. Such women, usually between the ages of 18 and 29, rarely present signs of pregnancy or show a belly, but may experience modest weight gain. Many also do not sense the baby kicking and continue to have menstrual-like bleeding.
Doctors are still perplexed by how women develop the condition in the first place. Social isolation, a history of substance abuse, and fear of pregnancy can all increase the risk. While most of the women do not suffer from a mental illness, psychiatric problems including mental retardation or major depression sometimes play a role.
"Denial of pregnancy is not well understood," says Stotland. "It does not have just one cause and it has not been well studied because most of the people involved do not seek or agree to psychiatric care."