WEYMOUTH (CBS) – It was the surprise delivery of a lifetime.

This week a Weymouth woman gave birth to a healthy baby girl, and she didn’t know she was pregnant until she went into labor.

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“Tuesday morning I woke up and I had crazy lower back pain,” Katie Kropas told WBZ-TV.

After feeling the pain, Kropas rushed to South Shore Hospital in South Weymouth.

“They told me that I had a full term baby, ready to come, now. So I found out at 10:15 and I had her at 11:06,” said Kropas.

Ellie was born at just over 10 pounds. (WBZ-TV)

Ellie was born at just over 10 pounds. (WBZ-TV)

Ellie was born at 10 pounds, 2 ounces.

The instant mom was shocked because she says she didn’t feel the typical signs of pregnancy.

“I thought I had put on some Christmas season weight, but I never thought I was pregnant.  Never,” she says.

It’s called a “cryptic” pregnancy, and it’s even the subject of a popular TV show called “I Didn’t Know I Was Pregnant.”

Dr. Kim Dever is chair of the Obstetrics and Gynecology at South Shore Hospital. She said it is not the only time the hospital has seen a similar birth.

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“We do about 3,500 births a year, and we probably see this a few times a year,” said Dever.

It happens when a woman is overweight or has irregular periods, and she may not feel much baby movement because of where the placenta is positioned, the doctor said.

“Very often, especially in your first pregnancy, you’re  really not aware of what you’re feeling and we often have women joke and say they’re feeling gas pains or they can attribute it to other natural conditions,” Dever said.

A Weymouth woman gave birth but didn't know she was pregnant until arriving at the hospital. (WBZ-TV)

A Weymouth woman gave birth but didn’t know she was pregnant until arriving at the hospital. (WBZ-TV)

Katie’s mother says she didn’t know it was happening either.

“I couldn’t believe it. I couldn’t get my head around it, and I live with her. As a female, there were no signs,” said Karen Kropas.

How often does it happen?  A British study found that one in 2,500 pregnancies is a surprise until labor begins.

Katie Kropas said that despite the major surprise, she is excited to spend time with her new bundle of joy.

“It’s going to be a hard couple of first weeks, especially since I didn’t have a lot of time to prepare but, I love her,” says Katie.

WBZ NewsRadio 1030’s Kendall Buhl reports

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