Planning ahead and taking care of yourself before becoming pregnant is the best thing you can do for you and your baby.

You need about 300 extra calories a day to maintain a healthy pregnancy. These calories should come from a balanced diet of protein, fruits, vegetables, and whole grains.

Many women today are waiting until later in life to have children. In the United States, birth rates for women in their 30s are at the highest levels in three decades.

Genetics is the study of the patterns of inheritance - how traits and characteristics are passed from parents to their children.

Genetic diseases are classified by type: chromosomal abnormalities, single gene defects, problems caused by exposure to certain substances, or a combination of these.

A "birth defect" is a health problem or physical change that is present in a baby at the time he/she is born.

A person can have normal chromosomes in number and structure, but still have a disease or condition caused by a mutation in one or more of the genes on the chromosomes.

Chromosome abnormalities usually happen as a result of an error in cell division.

Many women today are waiting until later in life to have children. In the United States, birth rates for women in their 30s are at the highest levels in three decades.

A family history of certain diseases or disorders or certain factors affecting the pregnancy itself may be reasons to visit a genetic counselor.