OK, to be geographically correct, the ovaries containing a woman’s eggs are outside of her uterus, but for purposes of the title, are we kumbaya with me taking some slight artistic liberties?

At any rate, one of the first questions a fertility doctor inevitably asks is your age. This is because it’s still one of the best indicators of your ovarian reserve — the quantity and, to some extent, the viability of your ovaries’ egg supply.

If the quantity itself is low, it’s usually called a decreased or diminished ovarian reserve. Ultimately, of course, what you really want to know is the quantity and quality of your eggs, in addition to how well your ovaries will respond if you’re going to use assisted reproductive technologies such as IVF.

We are born with all the eggs we will ever have, about 300,000, and after years of menstrual cycles, the supply is steadily depleted, which causes fertility to gradually decrease until about age 37. Afterward, it declines more rapidly, until menopause, usually by the early 50s. But if age were the only factor determining a woman’s fertility, there would be no need to even test her ovarian reserve.

In reality, even though ovarian reserves diminish over time in all women, the extent to which each individual woman’s does is unique. Most researchers now believe that the steeper decline in fertility to menopause is about 13 years—but the age a woman starts that decline can vary quite a bit. Therefore, two women of the same age may have completely different ovarian reserves. So, for example, you at 37 years old may ultimately go through menopause at age 50, so your decline may start about now. But your 37 year-old neighbor may go through menopause extremely early, at age 40, so her decline would have started as early as age 27. And that is why women who want to have children should monitor their ovarian reserve. More to come in my next blog . . .