Maternal weight gain closely relates to infant birth weight, but how much food do you need to eat and how much extra weight is a healthy amount to gain? Low birth weight babies have a greater incidence of malnutrition, which increases the chances of birth defects and illness.

It is important for a woman to increase her calorie intake when pregnant and doctors suggest that the proper weight gain for a pregnant woman is 25-30 pounds. Typically the extra weight gain can be broken down as follows.

Infant at birth - 7 pounds
Placenta - 1 pound
Blood increase - 4 pounds
Uterus increase - 2 pounds
Amniotic fluid - 2 pounds
Breast increase - 3 pounds
Fat stores - 5-10 pounds

Low birth weight babies are typically born to women who gain less that 20 pounds in weight with women gaining more than 35 pounds in weight probably adding excess bodyfat. In the first three months most women gain about 2-4 pounds, although some women can lose weight due to suffering with morning sickness. After the first three months, the average weight gain is about 1 pound a week.

The recommended calorie allowance for women of childbearing age is 2000 calories a day, plus 300 extra calories a day to support pregnancy. If the mother is exercising then additional calories will need to be added depending on the type of exercise performed, its duration and how often it is performed. Increased carbohydrates and the associate fibre from good carbohydrate food choices are important for an exercising pregnant woman as she will need the additional energy for her exercise and the developing baby's growth requirements.

The bodyfat that has been built up during the first six months of pregnancy is typically burned up during the last three months of pregnancy, with an additional 9 pounds of fat used for lactation and breast-feeding. Breast-feeding is a great way for the mother to get back in shape after childbirth as it uses 600-1100 extra calories above normal requirements to support lactation.

All vitamin requirements increase during pregnancy, however one vitamin in particular that is more important to pregnant women is folic acid, a B-complex vitamin. Folic acid requirements double during pregnancy and research has shown that folic acid taken in the early stages of pregnancy may prevent serious birth defects such as neural tube defect.

A pregnant woman performing exercise must also pay attention to fluid intake to replace body losses due to sweating and perspiration. Plenty of fluids also helps to keep the body cool and prevent a rise in body temperature which could harm the developing baby.

A balanced diet, with extra protein, carbohydrates, iron and calcium together with proper fluid intake will ensure a safe and healthy pregnancy for all active mothers-to-be.