On a visit to her doctor, 42-year-old Jennifer Williams of Minneapolis got an unexpected diagnosis. “The doctor read my lab report and told me I was pregnant” she says. Though the news came as a happy surprise for Williams and her husband, she also knew she hadn’t been preparing for a pregnancy. Once she got over the initial shock, she recalls, “My first thought was, ‘What do I need to do now to make sure this baby is healthy?'”

With more than half of all pregnancies in the U.S. unplanned, this is a frequently asked question, so here are some tips to improve your odds of a healthy pregnancy:

Review your medications: “As soon as you realize you’re pregnant, check with your doctor right away to make sure your medications are not incompatible with pregnancy,” says Mary Mahoney, assistant professor of obstetrics, gynecology and women’s health at the University of Minnesota. This includes prescriptions such as birth control pills, antibiotics and depression medication, as well as over-the-counter meds for anything from allergies to yeast infections. Do not stop taking prescription medications without your doctor’s approval.

Take your multivitamins: Folic acid has been shown to reduce the risk of certain birth defects that occur early in pregnancy. “The neural tube closes at about day 30, so if you haven’t been taking a multivitamin, start taking one with at least 400 micrograms of folic acid right away,” says Mahoney.

Cut out alcohol: Women who are pregnant should stop drinking wine, beer, and other forms of alcohol immediately.

Stop smoking: Quitting smoking early in your pregnancy can significantly reduce your baby’s risk of being born prematurely or with a low birth weight. Many hospitals and clinics offer smoking-cessation seminars or counseling to help expectant mothers kick the habit.

Eat your vegetables: “When it comes to nutrition, do just what your mother told you. Eat a balanced diet with plenty of fruits and vegetables,” says Mahoney.

Get moving: Talk to your doctor to make sure physical activity is safe for you during your pregnancy. Regular exercise can help reduce stress, boost energy, improve sleep and prevent excess weight gain during pregnancy, lowering your risk for complications such as gestational diabetes.

Editor’s Note: This article is not intended to provide medical advice, diagnosis, or other treatment recommendations, and is not a substitute for your doctor or other health care professional’s care .