Her daughter McKinlee was born Sept. 22, 2010, sharing the same birthday as Burger's uncle and grandfather McKinley, for whom the baby was named.

And her son started calling his friends' parents to tell them the news.

"He was calling everyone and telling them 'My mom's having a baby!'" she said. "And they're like 'No, quit playing jokes!'"

Prentice's story

Before this spring, Prentice and her husband had no children, and had been trying to have a baby for four years, without success.

She had always had irregular periods and thought she wasn't getting one because of stress. Her mother passed away in August of 2011, and she helped her father take care of paperwork.

The weight she gained, about 10 pounds, she attributed to drinking too much soda. She got sick once, but thought it was because of the barbecue she ate. As for the baby moving inside her, she probably thought it was gas.

One morning in April her husband came back from hunting to find Prentice in bed, unable to answer questions. There was blood on the floor from where she had bit her tongue during a seizure.

Her husband took her to a hospital in their hometown of Lawrenceburg, Tenn., but doctors there decided to send her to the larger medical center at Vanderbilt in Nashville. A helicopter took Prentice there. She doesn't remember any of this.

The staff at Vanderbilt performed a Caesarean section on the still-unconscious woman. She didn't wake up until two days later.

That's when her husband told her their daughter had been born.

"It made me so happy, but I was scared too, because I didn't know how far along I was, I didn't know if she was OK," Prentice said.

Prentice spent five days in the intensive care unit, while her daughter, Aleanna spent five days in the neonatal intensive care unit.

Before this, she was skeptical of women who aren't aware of their pregnancies; now, she watches "I Didn't Know I Was Pregnant" with a new perspective.

"I was one of these that was saying 'They've gotta know; they've gotta know.' Now: 'No, you don't have to know,' Prentice said. "If the good Lord wants it there, then he's going to put it there."

Risks of not knowing

There are several risks involved in having a baby if the mother didn't know she was pregnant for so many months. The baby hasn't been monitored properly, so doctors don't know which type of delivery would be safest; a large baby might be better served by a Caesarean section.

Doctors also wouldn't know about any abnormalities and complications associated with the fetus or the mother. The mom may need to take antibiotics for a bacterial infection, for example.

A mother who doesn't know she's expecting likely hasn't been monitored for hypertension, which was especially relevant for Prentice. On the day she went into labor she had ecclamspia, seizures that may result as a complication of pregnancy; high blood pressure is a risk factor.

The Amandas say they would have done things differently if they had known they were pregnant. Burger wouldn't have drunk alcohol or smoked and would have taken prenatal pills and seen a doctor. Prentice doesn't smoke or drink, but she would have watched her blood pressure more.

Burger noted that her first pregnancy was also somewhat abnormal. She was 19 years old and didn't experience any symptoms then, either. She found out she was pregnant when she was five-and-a-half months along. Her son Benjamin was born at 32 weeks.

"I've never really had a 'real' pregnancy," she said. "I have two kids and no real pregnancy."