Should old women have babies?
Until recently, this wasn't an issue. Nature exhausted your egg supply, and that was it. But technology has surmounted that problem. Now you can get in vitro fertilization, donor eggs, and womb-rejuvenating hormones. You can freeze your eggs or embryos. You can even freeze your ovarian tissue, reimplant it later, and resume ovulating.
Everywhere you look, moms are older. Over the last three decades, the U.S. birth rate among women aged 35 or older has increased by 140 percent. These women now produce one of every seven American children. In Europe, women over 35 have increased their share of pregnancies from 5 percent to 20 percent. More than 100,000 American women aged 40 or older have babies each year. In the last 15 years, at least a dozen women aged 60 or older have done it. The oldest age at which a woman has given birth is now 70.
Is middle-aged motherhood getting out of control?
The latest poster children for this controversy are the offspring of Maria del Carmen Bousada. Three years ago, Bousada, a 66-year-old unmarried Spaniard, pretended to be 55 and persuaded a California clinic to impregnate her using donated eggs and sperm. Later that year, she delivered twins. Two weeks ago, she died of cancer at age 69. Her 2-year-old sons are now orphans.
The case has provoked outcries around the world. "There's a lesson for baby boomers in the story of Maria del Carmen Bousada," wrote columnist Allison Pearson in London's Daily Mail. "The lesson is that, contrary to the fond belief perpetrated by the most self-absorbed generation ever to grace the planet, 60 is not the new 40 and it never will be." Pearson called Bousada "part of an epidemic of older women who think they can get away with defying biological laws that have held good for thousands of years."
That would be a tidy lesson, but it isn't quite true. The biological laws of maternity are shifting. Sixty may not be the new 40, but in some respects, 65 is the new 55. Maternal age is going up in part because, in terms of frailty and longevity, older women aren't as old as they used to be.
The clinic that impregnated Bousada ends eligibility for treatment at age 55. British and Spanish clinics have informal cutoffs at 50. Tony Rutherford, the head of the British Fertility Society, draws the line at 45 in his own practice. A bioethics institute is proposing to enforce the same limit in Spain. Britain's National Health Service cuts off in vitro fertilization at 40.
Why draw these lines? One rationale is nature. The British Fertility Society opposes fertility treatment after age 50 because "nature didn't design women to have assisted conception beyond the age of the natural menopause," says its secretary, Allan Pacey. "Once you get into the mid-50s, I think nature is trying to tell us something."
But what exactly is nature saying? Assisted conception is inherently unnatural. Strictly speaking, nature is telling us not to do it at all. Furthermore, in 1900, life expectancy for a girl born in the United States was 50.7 years. Was nature telling us that women shouldn't live, much less bear children, beyond that point? That didn't stop us from using science to extend women's lives. Why should it stop us from extending their fertility?