PITTSBURGH (KDKA) – Why do women go into menopause?
"The ovaries basically shut down," explains West Penn Hospital OBGYN Dr. Emily Lebovitz. "Why exactly that occurs we don't know."
Around age 50, women end their reproductive years -- an event called menopause. Hormones change, menstrual cycles stop, and natural childbearing is no longer a possibility.
Menopause could be nature's way of matching motherhood to younger bodies.
"It's certainly healthier for them to have children in their 20s, 30s, 40s, and then it becomes much more difficult," Dr. Lebovitz continues.
But a Canadian researcher says it's because of men, and because of competition.
Using computer modeling, he found competition among men of any age for younger mates left older females with less chance of reproducing.
He says the result is that genes favoring menopause got passed down through the generations, so that now it's a normal part of the female genetic blueprint.
But there are problems with this theory.
"That's an assumption that they made when they started their computer model, that men do like younger mates, and I don't think you can make that assumption," says Dr. Lebovitz.
What's more, if menopause is genetically determined and influenced by the environment, you would expect that some women would not go through menopause, or with increased life expectancy, the length of fertility might proportionally lengthen. But that hasn't been the case.
"We haven't seen a change in the age of menopause in general. It's somewhat preposterous to assume this has to do with men's choices," Dr. Lebovitz says. "Computer studies are difficult. Certainly population based studies can have more validity."
for more features.