Your Baby's Development
By week 10, all of your baby's vital organs have been formed and are starting to work together. Brain growth increases rapidly by this week - almost 250,000 new neurons are produced every minute in your baby's brain!

As external changes such as the separation of fingers and toes and the disappearance of the tail takes place, internal developments are taking place, too. Tooth buds form inside the mouth, and if you're having a boy, his testes will begin producing the male hormone testosterone this week.

Congenital abnormalities are unlikely to develop after week 10. This week also marks the end of the embryonic period, so your baby is officially considered a fetus.

Your Body
Your first prenatal visit, which often takes place around this time, is a milestone. At the doctor's office, you'll go through a series of tests and checks, including having your weight and blood pressure checked. You might also have an external abdominal examination to check the size and position of the fetus and have your urine tested. During this first prenatal visit, your health care provider will thoroughly examine you, including an internal examination and a breast exam. Your health care provider will also ask you many questions about your medical history and any family health problems, to determine if your baby is at risk for genetic diseases. Another thing your provider will check? Your baby's heartbeat! Using ultrasound, you should get to hear your baby's heartbeat for the first time.

As you leave your first appointment, your health care provider will probably send you for a blood test to find out whether you are immunized against varicella, measles, mumps, and rubella (German measles), as well as to determine your blood type and Rh factor. Rh factor is a substance found in the red blood cells of most people. If you don't have it (Rh negative) but your baby does (Rh positive), complications can result when the baby's blood cells enter your bloodstream. Your doctor can prevent Rh incompatibility problems by giving you a vaccine of Rh-immune globulin at 28 weeks and again after delivery.