BOSTON — NOT LONG AGO, after a midnight session with a male friend who was considering fatherhood at 50, I decided that middle-aged men suffer from a distinct biological disadvantage. They don't go through menopause.
This was a fairly quirky, contrary point of view. My friend did not long for the growth experience of hot flashes. It is more often women who resent the biological clock ticking loudly over their leisurely plans.
If anything, the female fertility deadline seems positively un-American, unfair. We are, after all, citizens of a country that believes in endless choices and unlimited options. Moreover, this biological destiny seems like a remnant of inequality: If men can have babies in their seventies, why not women?
Still, it seemed to me that the biological clock was a useful warning system about the life cycle. It was a way of saying that life changes and time runs out.
The female advantage was a built-in reminder that options have to be exercised and choices have to made. And if women focus more on the press of time and are less surprised by aging, maybe it's because of the ticking sound in their ears.
Now it appears that the biological alarm has been turned down. We are reading headlines that would have confounded our grandmothers: ''Menopause Found No Barrier to Pregnancy.'' Doctors have discovered a way to beat the clock. Post-menopausal women can become pregnant.
If this were just another entry in reproduction technologies, it would be unsettling enough. In the same month, we heard from California of a surrogate hired to carry the genetic offspring of another couple.
Now we learn that women can become, in essence, surrogate mothers for the children they want to raise. Seven women in or past menopause became pregnant with eggs donated by younger women and fertilized with their husband's sperm. More are on the way.
The emotional offshoot of this technology is complicated enough. Essentially, a pregnant woman can now carry a child conceived by her husband and another woman. How would that feel over time? How much pressure will an infertile woman feel to produce her husband's child instead of adopting? And in case of divorce, would the genetic parent have first psychological and legal claim?
Such queasy ethical questions trail behind each man-made variation on nature's theme. But this time the news is on the breaking of the age barrier.
I don't think pregnancy will become a popular retirement activity. I don't think it will be something for women to do in their sunset years when, at last, they have time.
Those most affected by this new option will be infertile couples, those who came to marriage late or menopause early, or have exhausted other biological possibilities. For these people, each new ''miracle baby'' produces another crop of questions: How far can they stretch their will and their wallet? How much of life should be focused on reproducing life?
The promise is that women can keep their biological door open, at least with the help of a stranger. The problem is that it also prevents closure. It changes the way we think about life. Among the seven who got pregnant was a woman who had undergone a range of fertility treatments for an entire decade. Morever, when this pregnancy ended in tragedy -- a stillbirth -- she decided to try again.
When you remove nature from the equation, there is a whole new set of calculations to be made. They bear, not surprisingly, a strong resemblance to the ones that men have faced.
A 45-year-old woman has, on the one hand, a 35-year life expectancy, more than a younger mother had a hundred years ago. A new mother at 50 may be healthier than her predecessor a generation ago.
But a menopausal mother becomes a senior citizen with teen-agers and a Social Security recipient paying college tuition. She may become dependent on her children just as they become independent. The issues become energy, and age gaps, and the real midnight on the biological clock: mortality.
One infertility counselor who heard about this ''breakthrough'' asked out loud, ''When do you say, enough is enough?'' The female body once said it for us. Now women, like men, will have to use much less predictable organs: the heart and the brain.