LONDON [Reuters, 22 Feb 2006] --- Older women are more likely to conceive twins because rising concentrations of a naturally occurring hormone over-stimulate their ovaries, according to a new study.
The discovery by a team of scientists from Amsterdam's Vrije Universiteit, revealed in Thursday's edition of the journal Human Reproduction, solves a riddle that has been perplexing the medical profession for years.
"The findings give credence to previous theories that the rising concentrations of follicle stimulating hormone (FSH) that occur as women age can cause some ovaries to go into overdrive, tripping them into a state where they have simultaneous double ovulation," they said.
More info on FSH can be found here.
You have to admire Dr Cornelius Lambalk and his colleagues from the Reproductive Medicine Division at Vrije University Medical Centre in Amsterdam. This is the first time scientists have demonstrated why older women are more likely than younger women to have multiple ovulations in the same menstrual cycle. I've been following Dr Lambalk's work since the late 1990s, when he theorized that there might be a connection between rising FSH levels and the occurence of twin births in older women. See this old JCEM abstract to see what I mean.
Suddenly, older women who plan to conceive now have reason to smile. Just when they thought they can no longer bear children, here now, is a documented explanation of why it is possible for them to have two instant babies. *LOL*
"Advancing female age is associated with declining fertility due to decreasing numbers and quality of oocytes, but at the same time there is a distinct increase in dizygotic twin rates --- a seemingly paradoxical phenomenon that has not been entirely explained, until now..." --- Dr Cornelius Lambalk
Indeed, nature has a way of compensating perceived biologic inadequacies.