You may think that getting pregnant once means you'll have no trouble next time. But 20 percent of women have a condition known as secondary infertility, according to Alice Domar, Ph.D., executive director of the Domar Center for Complementary Healthcare at Boston IVF. It's especially common among moms who waited to start a family until their 30s and 40s, when fertility declines. Fortunately, there's a lot you can do to increase your chances of getting pregnant:

Start prenatal vitamins now
Folic acid and iron can improve fertility. Regular multivitamins may not contain enough of these nutrients for you to get their full benefits, but you'll be covered with a prenatal. Try to take it with food for better absorption.

Zero in on your window
Your eggs are fertile for as few as 12 hours each month! An ovulation predictor kit pinpoints the best time to have sex by showing when you're most fertile. Disposable pee-stick tests cost around $40 for several; computerized kits, like the Clearblue Easy Fertility Monitor, are more expensive (almost $200) but also more accurate.

Create the right conditions
Antihistamines and vitamin C supplements can dry out the cervical secretions that escort sperm to your egg, so try to avoid them. A lubricant may sound like a good idea, but too much can block sperm's path. Try Replens moisturizer instead. It lasts longer than lubricants (up to three days), so you can use less.

Get tested
If you're 35 or older and have been trying to conceive for more than six months, see your ob-gyn. (Women under 35 can wait a year.) Your doctor will likely run you through a series of tests to try to find the cause of the problem. Make sure you're up-to-date on your Pap smear, and also request a Day Three FSH/estradiol blood test. For $50, this test measures the hormone that revs up your ovaries for ovulation. High levels indicate that your body is working harder to get your ovaries moving  -- likely because your egg supply is low.

Relax
The stress hormone cortisol can interfere with ovulation and lead to low fertility. Do whatever calms you, whether it's getting away for the weekend, exercising, or meditating. And consider talk therapy. In a study of women who weren't ovulating, 77 percent of those who learned to reduce stress through therapy began ovulating again.

Try acupuncture
It's safe and has several proven benefits for moms trying to conceive, including increased blood flow to the uterus and stimulation of fertility hormones. You'll need anywhere from a couple of treatments to a few months' worth, depending on your situation. Each session costs $50 to $90 (not usually covered in full by insurance). To find a practitioner, ask your doctor for a referral or search for one by zip code at the American Academy of Medical Acupuncture's website

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