Fetal Health and Development—Birth Weight

Birth weight is the first weight of your baby, taken just after he or she is born. A low birth weight is less than 5.5 pounds. A high birth weight is more than 8.8 pounds.

A low birth weight baby can be born too small, too early (premature), or both. This can happen for many different reasons. They include health problems in the mother, genetic factors, problems with the placenta and substance abuse by the mother.

Some low birth weight babies may be more at risk for certain health problems. Some may become sick in the first days of life or develop infections. Others may suffer from longer-term problems such as delayed motor and social development or learning disabilities.

High birth weight babies are often big because the parents are big, or the mother has diabetes during pregnancy. These babies may be at a higher risk of birth injuries and problems with blood sugar.

Centers for Disease Control and Prevention

Large for gestational age (LGA) (Medical Encyclopedia)
Neonatal weight gain and nutrition (Medical Encyclopedia)
Small for gestational age (SGA) (Medical Encyclopedia)

A normal pregnancy lasts nine months. Each three-month period of pregnancy is called a trimester. During each trimester, the fetus grows and develops. Regular medical checkups and prenatal tests are very important. They can

Help keep you and your baby healthy
Spot problems with your baby (if there are any). In some cases, health care professionals can treat the problem before your baby is born. But even when they cannot, it can still be helpful to know about the problem early on. That gives you time to learn about your baby’s condition and prepare for any challenges you may face after the baby is born.
Prevent problems during delivery. For example, if your baby is breech (bottom first or feet first, instead of head first), you may need to have a Cesarean section to avoid complications.

Besides getting medical care, there are other things you can do to keep your baby as healthy as possible. It’s important not to drink or smoke. Try to eat a healthy diet and make sure to take care of any health problems you have during pregnancy.