About Fetal Development

Developmental Overview

• When a baby is conceived, it is known as a zygote. Your baby does not become a fetus until about the 11th week of your pregnancy, according to MayoClinic.com. Typically, pregnancy lasts 40 weeks, and it is divided into three trimesters, each about 13 weeks long. Your baby becomes a fetus near the end of the first trimester and then experiences rapid development over the second and third trimesters.

Developmental Milestones

• As the fetus grows in the womb, your doctor will chart specific developmental milestones. Between 11 and 14 weeks, your baby will develop tooth buds, can make a fist and has a well-formed face, according to the National Institutes of Health. Your baby's heart and blood vessels are fully formed at 16 weeks, WebMD states. By 19 to 21 weeks, the NIH states that your baby can hear. Your baby's development continues rapidly throughout the pregnancy. Regular prenatal visits are essential so that your doctor can ensure that development is progressing as it should.

Weight Gain

• Weight gain is a concern for many pregnant women, but the right weight gain can be a sign of healthy development. Early in pregnancy, babies gain very little weight. Baby Center says that the average weight for babies at 12 weeks in utero is 0.49 ounces. By the end of 24 weeks, the average weight is 1.32 pounds. Near the second half of the third trimester, babies can put on 5 ounces to a half a pound each week as they start to store fat as part of their healthy development.

Promoting Healthy Development

• The best thing that pregnant women can do to promote healthy fetal development is to practice good self-care and attend regular prenatal visits. Self-care includes getting enough sleep each day, eating a healthy diet with enough calories -- about 200 to 300 additional calories per day, and cutting out harmful substances such as smoking and alcohol. Your doctor may also recommend a prenatal vitamin. At your prenatal appointments, your doctor will measure your uterus, listen to your baby's heartbeat and ask questions about your symptoms to ensure that your baby is developing well.