Weve all seen the news that shows a proud mother cradling her newborn, but looking baffled she didnt know she was pregnant until she was in labor. (Thats the news portion of the story.) For those who have been pregnant before, were perplexed and puzzled. After all, how can you miss all of the pregnancy signs and symptoms of pregnancy? Most women are chomping at the bit to take a pregnancy test the minute their period is late.
According to research, the state of denied pregnancy is not uncommon. In fact, not knowing you are pregnant until you are 20 weeks pregnant happens in about 1 in 475 pregnancies. They add that denial of pregnancy at 20 weeks' gestation or later (one in 475 pregnancies) occurs more often than Rh disease and some other things we think of as fairly rare.
While it is a bit more rare to not know until youre in labor, about one in 2,455 births. Though when you put that into perspective, you learn that youre actually three times more likely to give birth without knowing you were pregnant than you are to give birth to triplets! (1 in 7,225 pregnancies) In fact, when researchers extrapolated the data to a country like Germany, it found that about 300 mothers a year would not know they were pregnant until they started labor.
The researchers are proposing that a specific category of medical classification be added under reproductive dysfunction for negated pregnancies. This would include denied or concealed pregnancies. It may also include false pregnancy (pseudocyesis), obsessive desire to have children and other pathological behavior of a mother towards her offspring.
This is not a problem with only a certain subset of women, it happens in every socioeconomic group, race, religion, etc. Either way the bottom line is that not knowing your pregnant, even for 20 weeks of pregnancy, has the potential to risk the health of the mother and baby.
Source: Denied and concealed pregnancies. Journal of Psychosomatic Research 2006; 61: 723-30.
Surprise births not uncommon. British Medical Journal 2002; 324: 458.

