AT THE WRITING of this column, the Smithsonian National Zoo's panda exhibit was closed. The zoo needed time for its zoological experts to determine if the giant female panda, Mei Xiang, is pregnant. I imagine it does take time to coax a giant panda into cooperating for a pregnancy test, especially if she's experiencing hormonal fluctuations.

I'm joking, of course; there are no pregnancy tests for pandas. But if you are a mother, or are married to a mother, or even have a mother, you may know that the hormones that allow for the miracle of motherhood can also wreak havoc on our moods.

It's important to respect hormonally induced mood changes as a part of the female experience. For example, a 2005 literature review by researchers determined that mood lowering was associated with the primary sex hormone, estrogen. Sudden estrogen withdrawal, times of sustained low levels of estrogen and estrogen fluctuations were all associated with significant mood lowering.

If you are a woman who has lived through puberty, a couple of pregnancies, 40 years' worth of menstrual cycles and then menopause, these findings will be no big surprise.

When it comes to all the many hormonally induced physical and mental changes, mothers do seem to get the short end of the procreational stick.

IN THE BEGINNING

Hormonally induced mood changes occur in girls long before a pregnancy and can continue throughout a woman's life. First, they appear just as the potential for pregnancy begins--at puberty.

Fortunately, our educational system does a pretty good job of explaining--in family life courses, for example--about the hormonal and physical changes that occur in girls before they begin to actually experience them.

Parents are also more aware than ever of the need to have open communication with our tweens. There is a great talking guide for parents online at cnnhealth.com titled "Holy Hormones! What to Expect When Puberty Hits."

WITH CHILD

When you think about all the changes a body endures to carry a pregnancy to term, it is not surprising that there might be a little emotional fallout from the whole experience.