Dr. Manny Alvarez, senior managing health editor of FoxNews.com, recently received this question from a viewer:

Q: I’m 27 years old, and my husband and I are trying to start a family. I’ve had some bad habits in the past, like smoking, and I have a pretty stressful job. Could these types of things affect my chances of getting pregnant?

Alvarez said there are some factors that may be out of your control when it comes to fertility, such as medical issues or genetics.

But your lifestyle choices can definitely affect your chances of getting pregnant.

You should avoid these bad habits, in order to protect your fertility:
• Alcohol – Heavy drinking is associated with an increased risk of ovulation disorders, and some research has shown that even light drinking can reduce the likelihood of conceiving.

• Excessive caffeine – Too much caffeine can have an effect on your estrogen levels, and contribute to fallopian tube damage and endometriosis. Remember, caffeine is found in things like tea, chocolate, soda and energy drinks.

• Stress – Even mild stress can inhibit ovulation.

• Excessive, vigorous physical activity – Too much intense aerobic activity can reduce the production of the hormone progesterone and affect ovulation. Limit exercise to one hour per day. If you are overweight, consult with your doctor.

• Smoking - Besides damaging your cervix and fallopian tubes, heavy smoking ages your ovaries and depletes your eggs. Nicotine and other chemicals in cigarettes interfere with estrogen production and can cause eggs to be prone to genetic abnormalities.

If you are thinking of becoming pregnant, and you have any concerns about your lifestyle choices – talk to your doctor. He or she may be able to help you improve your chances of conceiving without fertility treatment.

If you have a question for Dr. Manny, e-mail him at drmanny@foxnews.com