The days that immediately follow conception are some of the most important in the development of a child. Because nearly half of all pregnancies in the US are unintended, many women will learn that they are pregnant before they've had a chance to make lifestyle changes beneficial to both mother and growing fetus. Whether you're actively trying to have a baby or not, it's never too early to prepare for a healthy pregnancy, birth, and baby.

The American College of Obstetricians and Gynecologists encourages reproductive-aged women to talk to their doctors about preconception care. You can discuss your desire for children, the optimal time to have them, the amount of space you'd like between pregnancies, and your current birth control needs.

Your doctor can also review personal health information that could affect a future pregnancy, such as family medical history, environmental and work-related exposure to harmful substances, the risk of sexually transmitted infections, and substance abuse.

If you are considering having children, your doctor may suggest some changes before you conceive.

Diet. Folic acid and other vitamins and minerals are vital for healthy fetal development, but most women do not receive enough of these nutrients in their diets.

Exercise. If you do not currently get at least 30 minutes of exercise on most days, your doctor may recommend that you increase activity now for a more active and comfortable pregnancy later.

Weight. Being overweight can cause high blood pressure and diabetes, put extra stress on your heart, and increase the chance of having a very large baby. Underweight women may find it difficult to conceive and are at risk of delivering low-birth-weight babies. Aim to fall into the normal BMI range for your height.

Preexisting medical conditions. Women with medical conditions such as diabetes, high blood pressure, seizures, heart disease, or obesity may need special care during pregnancy or may be using medications that are harmful to fetuses. Try to get your condition under control and check the safety of all current medications with your doctor.

Substance abuse. Smoking, drinking, and using illegal drugs have been proven to cause birth defects in newborns. Women contemplating pregnancy should not use these substances.

For more information, the ACOG Patient Education Pamphlet "Good Health Before Pregnancy" is available at www.acog.org/publications/patient_education/bp056.cfm. ?