
According to the CDC, about 4.3 million babies were born in the U.S.
in 2007. During pregnancy, a woman needs to provide nourishment for
herself and for the growing fetus. In 2009, the Institute of Medicine
(IOM) issued updated guidelines on pregnancy weight gain, recommending
women of normal pre-pregnancy weight gain 25 to 35 extra pounds.
By the end of the pregnancy, the weight of the baby accounts for
about one-fourth of the total weight gain (roughly 7 to 8 pounds).
Another seven pounds is for maternal stores of nutrients, protein and
fat. The rest of the weight can be attributed to the placenta (1 to 2
pounds), amniotic fluid (2 pounds), uterus (2 pounds), breast tissue (2
pounds), body fluids (4 pounds) and maternal blood (4 pounds).