Your baby has grown a great deal in the last week and may be close to 7" (17 cm) long and weigh about 13.5 oz (383 g). Plus, he's moving around more than ever, so you are probably very aware of the little person inside you! At this stage of development, fetal movement, breathing activity, and heart rate begin to follow daily cycles called circadian rhythms, the basic biological and behavioral rhythms that occur during a normal 24-hour cycle. This means your baby's sleeping and waking periods are becoming more predictable. Unfortunately, they don't necessarily coincide with yours! Fetuses are often most active in the late evening, just when mom is trying to go to sleep.

Two important new developments: your baby can now swallow, allowing him to absorb glucose and water from the amniotic fluid. His nutrition is still almost entirely supplied by you, however, through the placenta. Also, although the liver and spleen are still making blood cells (and will do so up until the time of birth), the bone marrow has started making them as well.