26 August 2016

'I didn't know I was pregnant'

'Cryptic pregnancy' occurs when a woman doesn't know she is pregnant, and the phenomenon is more common than most people think.


When Amanda Burger from Iowa in the USA went to the hospital after she felt stomach cramps, she thought she had nothing more than a really bad stomach bug. But a few hours later she walked out of the hospital with a new-born daughter.

“They had to break my water and then she pretty much just fell out,” Burger told CNN.

The 33-year-old mother had no signs pregnancy and just like the stories on TLC’s I didn’t know I was pregnant it felt surreal when she gave birth.

Read more: Five danger signs in pregnancy you should not miss

She picked up 6–9kg during the unknown pregnancy and didn’t think much of it. “I'd go to the pool in a bikini,” she said.

Not that uncommon

Surprisingly, Burger’s situation is not uncommon as one would think and doctors often label this phenomenon as “cryptic pregnancy”. A Serbian study showed the prevalence of “an unknown pregnancy during the first 20 weeks is 1 in 475 pregnancies, in the second half of pregnancy it is 1 in 2 455 pregnancies and at the moment of delivery it is 1 in 7 225”.


Most people, especially women, often wonder: How can you not know you are pregnant? The body undergoes so many changes during pregnancies that it’s almost inconceivable to not be aware of it. But research from University of Turin shows there are many reasons why a woman won’t notice she’s pregnant. Some of the biological reasons are:

  • Unnoticeable extra weight among obese women. Some women who are already overweight can pick up a few extra kilograms over the course of a nine-month term and not notice it.
  • Neonates tend to be underweight. Especially premature babies are underweight and some women don’t notice the extra weight.
  • Minimal pregnancy symptoms. Some women simply don’t experience pregnancy symptoms such as fatigue or morning sickness.
  • Irregular menstrual cycle. Usually menstrual periods stop at the onset of pregnancy, but some women experience irregular menstrual cycles even when they are not pregnant. If this unusual pattern continues during pregnancy it’s difficult to recognise it as a sign of pregnancy.
  • Foetus barely moving in the womb. Most babies kick, but some are not very active. Some movements can also be mistaken for digestive issues or even a stomach bug.  

Read more: Is fish safe during pregnancy?

Stress and denial

Sometimes bodily symptoms of pregnancy are subtle, but noticeable and some women are in denial about the pregnancy. Even without a history of mental illness external stressors such as financial difficulties or relationship problems can cause such psychological distress that a woman “blocks out” her pregnancy.

Research also suggests an evolutionary response called “forced cooperation” between mother and foetus. The case of reduced survival probability, “both mother and foetus would benefit if the mother reduced investment in pregnancy in order to maximize her chances of surviving and reaching delivery”.

Read more:

Fat in pregnant women's diet affects babies' gut microbes

5 tips on incontinence in pregnancy and childbirth

Childhood radiation: pregnancy problems


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