Women who were anxious about the medical aspects of the procedure had nearly 20 percent fewer eggs to fertilize, according to the study. Women who stressed about missing work had 30 percent fewer eggs to fertilize. And women who worried about the cost of IVF were 11 times more likely to not achieve a healthy birth. Ways to cope:

• If you're nervous about the medical aspects of IVF, ask your doctor to walk you through each step of the process before you get started, says study author Hillary Klonoff-Cohen, Ph.D., a professor of family and preventive medicine. And don't spend too much time in Internet chat rooms, where people tend to talk about their bad experiences, says Alice Domar, Ph.D., director of the Mind/Body Center for Women's Health at Boston IVF.

• If you're anxious about missing work, know that you'll need daily ultrasounds and blood tests  -- most likely in the morning  -- and shift your schedule in case you'll be getting in late. "If your doctor orders bed rest, arrange to work at home, if possible, or use vacation or sick days and don't feel guilty," says Klonoff-Cohen. If you know your boss will be supportive, tell her what's going on.

• Concerned about the cost? Review your insurance policy: Even if IVF isn't covered, some procedures associated with it might be. Also, ask about discounts for uninsured or underinsured patients, which clinics usually won't advertise, says Domar.