How an 18 Week Fetus Develops

At this time of your pregnancy, your baby measures about 12cm long from crown to rump and weighs at about 200 grams. The baby’s chest moves up and down to mimic breathing. She can now hear sounds and may be startled when loud noises are heard. Through her thin skin, blood vessels now become visible. Her two ears are now in their final position although they’re still standing out from her head a bit.

The baby’s skin is now building a protective wax layer called vernix. Vernix is being accumulated on her body along with the lanugo which is a soft lightly pigmented hair covering the body and limbs. Vernix is a white cheese-like protective coating which protects the baby’s skin by keeping it moisturized in the amniotic fluid. Both the lanugo and the vernix help in protecting your baby’s skin during the months in water.18 Week Fetus

The baby in your womb may hear your heart beats, your stomach rumbles or blood moving through the umbilical cord. At this time, tiny air sacs which are called alveoli begin to form in the vocal cords and the lungs. The baby is now going through motions of crying but without air so it doesn’t make a sound yet. This is also the time when your baby’s vocal cords are forming and she will begin practicing her vocals inside the womb. Your baby may have awake and sleep patterns like that of a newborn. Your baby will have her favorite position for sleep and recognizable rest and active periods. At this time also, the baby’s brain is rapidly growing as well as the major areas of the body. She starts to responds to stimuli like loud sounds.

An ultrasound will now determine your baby’s gender. A baby girl will have her Fallopian tubes and uterus formed along with her genitals. And a baby boy will have pronounced genitals as well which will be visible in an ultrasound. During the ultrasound, you might see your baby flex, kick, roll, reach or even suck her thumb.