"The siblings cared for one another," Peters said. "I was cared for by my mother and my older siblings."
The Duggar family has a similar approach, with older siblings helping to take care of the younger ones.
Matt Hersh, an expert on children and adolescent fear and anxiety at Boston University, said that's not necessarily a bad thing, depending on the expectations the parents set up for their children.
"If that's an expectation, as in that's just how we function, it may not be perceived as burdensome," he said.
"In my limited knowledge of the Duggar's philosophy -- that every child is a particular gift for the family -- I imagine that would help ease the role."
To this day, Carroccio said, she remains very close with her second-oldest sister -- "she was like a second mom to me." At 18, Carroccio moved in with her older sister and still turns to her when she has a problem.
Still, thinking about the Duggars' having their 19th, Carroccio said, "I feel like it's too much. I'm sure no one is going to be neglected. But it does seem overwhelming."
Peters said she recalled looking out the kitchen window of her childhood home one day while washing a huge pile of dishes and thinking, "I can't wait till I get out of here."
She said she never wanted a big family. Then, she met her husband, Don Peters, a technology and computer specialist, and they married when she was 18. Five years later, they bought the property where her childhood home stood and built a house. They have since filled it with 10 children, ranging from ages 4 to 28.
"I never wanted to have a big family because I lived in one," said Peters, a stay-at-home mom. "But it came about through the love between my husband and me. Children are a gift from God, and God knew what was going to be right for us."
It's a philosophy to which the Duggars, devout conservative Christians, subscribe. But one's belief in God should not minimize other important issues involved in families so large, medical and environmental experts say.
In addition to the hemorrhage risk, Cain, the chief OB-GYN at Women & Infants hospital in Providence, said women such as Duggar, after their child-bearing years, are also at greater risk of incontinence and even uterine prolapse, in which the uterus falls to the pelvic floor.
"This woman is lucky that she exists in a society where if she has any of those complications, we have ways of dealing with them," Cain said. "Yes, women used to have that many children. But many mothers didn't survive, and their children died at an earlier age. We forget that."
Dr. Amy Sarver, Duggar's OB-GYN, told People magazine after she delivered Duggar's 18th baby, "Some women are made to have babies, and Michelle is to the nth-degree."
Alan Weisman, the author of "The World Without Us," raises another concern, about the Duggar family's impact on the environment. Each child, he said, multiplies his mother's carbon legacy by 5.7 percent, which means the Duggar children alone could be responsible for contributing more than a million metric tons of carbon dioxide to the atmosphere.
"Big families have always been portrayed as something lovable and beautiful," Weisman said. "Think of 'The Waltons.' But we do have an issue now, where it's not just about home and family. It's about the planet, and the planet hasn't gotten any bigger. We only have one atmosphere."