Your baby's facial features are becoming better defined, and full eyelashes and eyebrows are growing in. He's looking more like a newborn every day! His growth is clearly visible on the outside, but important developments are occurring inside the little guy, too. Though some folds have been forming in the brain's cerebral cortex, up until this time it's been relatively unwrinkled. Now, however, numerous furrows have begun bunching on the outer surface. Along with them come greater, more localized brain functions. The centers for sight, smell, hearing, speech, walking, and all other sensations and activities are in place. The sites and connections governing reason, memory, and imagination have yet to develop, but at this stage the brain has advanced sufficiently to control rhythmic breathing, contractions in the digestive tract, and body temperature: three major thresholds for living outside the womb.

Baby's bones are hardening so that they can support him outside of the liquid world he now lives in. An exception is his skull, which isn't yet fully solid but contains five unconnected bony plates called fontanels ("little fountains"). This is a safety precaution for reducing the skull's diameter in its passage through the birth canal. The unfused plates allow baby's head to elongate during childbirth, then return to a rounded shape afterward. Your baby may retain the "soft spot" on his head for up to a year after birth.