What is the most important thing during pregnancy?

Eat breakfast every day. Eat foods high in fiber, and drink fluids (particularly water) to avoid constipation. Avoid alcohol, raw or undercooked fish, fish high in mercury, undercooked meat and poultry, and soft cheeses. Do moderate-intensity aerobic activity at least 150 minutes a week during your pregnancy.
Take folic acid and vitamin D supplements

Folic acid significantly reduces your baby's risk of neural tube defects, such as spina bifida. If you are pregnant, start taking 400 micrograms of folic acid as a supplement as soon as possible until the end of the first trimester (week 12 of your pregnancy).

Health Tips for Pregnant Women:
Healthy Weight
Healthy Eating
Physical Activity
After the Baby Is Born

Having a baby is an exciting time that often inspires women to make healthier lifestyle choices and, if needed, work toward a healthy body weight. Here you’ll find tips on how to improve your eating and physical activity habits while you’re pregnant and after your baby is born.

These tips can also be useful if you’re not pregnant but are thinking about having a baby! By making changes now, you can get used to new lifestyle habits. You’ll give your baby the best possible start on life and be a healthy example to your family for a lifetime.