05/14/2015 07:10 EDT | Updated 05/14/2015 07:59 EDT

Cryptic Pregnancy: Yes, You Could Be Pregnant And Not Know It

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Last Sunday, a B.C. woman gave birth on an Air Canada flight en route to Japan. Despite taking a pregnancy test and consulting a doctor before her trip, Ada Guan says she had no idea she was pregnant.

She joins a number of similar cases popping up in the news lately. Earlier this month, a California woman discovered she was eight-months pregnant after her boyfriend felt her baby kick. Back in April, a Pittsburgh woman unexpectedly gave birth in a Wendy’s parking lot.

When we read these stories of surprise pregnancies, many of us wonder: How could that happen? Is it actually possible? Turns out, it is. Although, Dr. Doug Wilson, the department head of obstetrics and gynecology at the University of Calgary, says these occurrences are rare.

“The vast majority of women will have early nausea, will have breast tenderness and things like that and also missing a period,” he told Global News. “Sometimes if you don’t think it can happen to you, you’re going to deny some of those very normal symptoms and put them down to indigestion, or the flu, or one of those types of things.”

Vancouver obstetrician Dr. Shelley Ross agrees. “It's pretty rare,” she told CBC. “It's pretty hard to deny a large mass in the front of your abdomen.”

So why do some women have unforeseen pregnancies?

There are two theories as to why women have cryptic pregnancies, meaning they don’t realize they’re expecting. The first is that the woman denies the pregnancy, and the second is that her symptoms are not obvious.

Bryan Jick, a California obstetrician-gynecologist, explains that not every woman has a regular menstrual cycle, so even the obvious sign of missing a period might not tip them off to their pregnancy. Additionally, obesity can mask weight gain and pregnancy tests are known to sometimes give false results.

Pregnancies might also go unnoticed if little or no HCG (human chorionic gonadotropin) is detected in the mother’s system. HCG is a hormone produced by the fetus that turns pregnancy tests positive. Fetuses might not produce enough of this hormone if there are fetal birth defects, genetic abnormalities, or if the mother is under a lot of stress.

B.C. mom Josephine Anglin had a surprise pregnancy herself. After going to the hospital for severe back pain, she ended up giving birth to a baby girl weighing 8 pounds, 14 ounces.

“It's amazing how you can go from working every single day and not knowing you're pregnant,” Anglin said. “And then all of a sudden, you're on maternity leave, you have a baby. It's quite a shift.”

According to statistics, 1 in 450 women don’t know they’re pregnant until 20 weeks or later and 1 in 2,500 go undiagnosed until labour.


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