Talk aboushing it literally. The oldest woman in the united states ever to give birth to twins. When a lot of people are thinking about retiring, she's starting a new full-time job. Motherhood. Here's... See More
Talk aboushing it literally. The oldest woman in the united states ever to give birth to twins. When a lot of people are thinking about retiring, she's starting a new full-time job. Motherhood. Here's elizabeth vargas. Reporter: The face of motherhood is aging. When this provocative magazine cover hit newsstands, it raised eyebrows and had many people asking, just how old is too old to become a mother? Turns out that cover was a fake, a doctored photo inspired by this iconic shot, but this extreme mother is real. Meet frieda birnbaum. Five years ago, she became the oldest american woman to give birth to twins. I was just as shocked that i turned 60 while I was pregnant. I think the six part of it hit a nerve with people. Reporter: Hit a nerve and set off a media firestorm. Is it are you too old to become a new mom? You'll be close to 80 when the boys are in school. The scrutiny may have been a surprise. But for frieda and her husband ted, parenthood was nothing new pp 35 years ago, they welcomed their first child, jaeson. I was 26, and I had a wonderful, beautiful son. And my daughter came next, four years later. ♪ Reporter: While raising her children, frieda went to school and became a psychoanalyst. But after years of juggling work and family, with her kids off to college, something surprising happened. So you started to feel a biological urge to have more CHILDREN ONCE YOU HIT YOUR 40s? And I just had this instinct when I saw a baby, that I just wanted to take that baby away and run. You know, hold it and hug it. As you get older, I've found i have more of an urge to have children than when I was younger. Reporter: That urge wasn't just to be a mother again, but give birth herself. For frieda, that would mean turning to in vitro fertilization. But even with the latest in fertility technology, the chances of a woman in her late 40s BECOMING PREGNANT ARE Microscopic. Reporter: And what were doctors telling you, when you were saying, I'd like to get pregnant? They say, "fine, come on, we'll do it." But they don't -- I felt that this one doctor that was -- we worked with him for many months. He didn't seem like his heart was in it. Reporter: Well, I'm sure he didn't think you'd get pregnant. I don't know. He just -- he justlike he said, it could be done. Reporter: Against extraordinary odds, he was right. At 53, with 2 children already IN THEIR MID-20s, FRIEDA GAVE Birth to her and ken's third child, ari. It was such a wonderful thing. Everybody in the family was so excited. I said, "you know what? Let's do it again. Reporter: You heard that right. Frieda had frozen four unused eggs, on the off chance she might want to try her luck again. And she did. So why did you decide to get pregnant again? The real story is, I didn't have children because I wanted to feel younger or look younger. I had children for my husband. Call me stupid, which I am, but I did it because -- the look on your face. I did it because he said to me, "try it." Reporter: But at 59, frieda was well past the age most fertility doctors consider safe to perform ivf. Undeterred, the birnbaums kept searching and found a solution 8,000 miles away where age was less of a concern. In south africa, it was different because they were not as strict. They seemed very flexible with everything. Reporter: So nobody asked for a birth certificate. Just -- nothing. Nothing at all. Reporter: But did you tell them that you were younger than you were? I told them that I was -- you may have. I may have. Reporter: Certain details may now be fuzzy for frieda, but her older children's reaction at the time was crystal clear. Jaeson was angry at me. He actual called the clinic, said we were crazy, said he would make trouble. Reporter: And frieda's son wasn't the only one questioning her sanity. Reporter: How do you find a doctor in the u.S. And were you honest with them? Yes, I was honest. R. By walking in and saying, I'm 59. And the doctor didn't believe me. And then he must have thought i was a little whatever when i told him the age. Reporter: Skepticism that was easy to understand. At 60, the birth of frieda's twins was unprecedented, and some thought irresponsible. When these 5-year-olds enter college, frieda will be 78 and her husband will be 81. So, ari, does it feel like your mom and dad have enough energy for all of you guys? No. Reporter: No? They seem to get very tired easily. Do your friends sometimes ask you how old your mom and dad are? Yes. Reporter: What do you say? I say, "they are very old." Reporter: I'm sure they really appreciate that. But these days the, birnbaums seem determined to prove the old adage, children keep you young. Don't touch again. I love you, I love you, but i don't like what you did. It wasn't nice. Reporter: Chasing after their own boys, but also grandchildren as well. Why not lavish all that love and attention on your grandkids? Well, we love it. But why -- why should we? I mean, who's setting the rules here? And as you get older, you see that the authority is you. And who is jaeson? Jaeson didn't see the children for two years. And now his daughter plays with josh a lot. He loves the kids. You're her uncle? Yeah. Reporter: Do you really think that it's fair to these little boys to have parents ad as you? I can only say that I have no less energy now than I had when I was younger. Reporter: You think you're just as energetic at 64 as you were at 26? I think I'm more energetic. I am definitely more energetic. We have to redefine age because it's changed. This is not unusual. Reporter: Why do you think, though, so many people are critical of your decision to have children this old? I think because this age is supposed to mean something else. This is supposed to mean retirement. Reporter: Well, don't you want to relax and travel and have fun? And not be up for -- I'll do that when I'm 80. I'm so inspired by life. I'm so excited by life. I'm more excited by life now than ever before.
This transcript has been automatically generated and may not be 100% accurate.