Average fetal length and weight chart

From early on in pregnancy, babies grow at different rates, so these numbers are merely averages. Your baby's length and weight may differ greatly from these figures. Don't worry too much if an ultrasound scan indicates that your baby is much smaller or larger. Your doctor will let you know if you should worry about what size your baby is.

By full-term, your baby may end up weighing fewer than five pounds or more than nine. For the purposes of this chart, babies are measured from the crown (or top) of the head to the rump (or bottom) until about 20 weeks.

After 20 weeks, they're measured from crown to heel. This is because a baby's legs are curled up against his torso during the first half of pregnancy and very hard to measure.

What is a pregnancy test, and how does it work?

A pregnancy test can let you know if you are pregnant. Pregnancy tests check your pee or blood for a hormone called human chorionic gonadotropin (hCG). Your body makes this hormone after a fertilized egg attaches to the wall of your uterus. This usually happens about 6 days after fertilization. Levels of hCG rise quickly, doubling every 2 to 3 days.

Routine Visits and Testing

You should call to schedule your first checkup during the first 6 to 8 weeks of your pregnancy, or when your period is 2 to 4 weeks late. Many health care providers will not schedule the first visit before 8 weeks, unless there is a problem.

If you're healthy and have no complicating risk factors, you can expect to see your health care provider:

  • Every 4 weeks until the 28th week of pregnancy
  • Every 2 weeks until 36 weeks
  • Once a week until delivery

At each checkup, your weight and blood pressure are usually recorded. The size and shape of your uterus may also be measured, starting at the 22nd week, to see whether the fetus is growing and developing normally.