Development Calendar

Your Pregnancy Month 4

What's Your Baby Up to This Month?

MONTH 4: 15-18 weeks gestational age

Your Pregnancy Month 4: 15-18 weeks gestational age

The lateral fissures begin forming on the cerebral cortex of her brain
She's growing eyebrows, and hair
Her visual cortex develops, the 1st step in her visual development
She's now more than 5 inches long and weighs 4 ounces

What's Going on in That Brain of Hers?

Your baby's brain never stops working. This month it is busy developing one of its distinctive grooves, called the lateral fissure in the cerebral cortex, the part of the brain that will become responsible for complex functions like memory, language and consciousness.

As you learned last month, your baby gets all the nourishment she needs for her busy workday from you via the umbilical cord. So it's more important than ever to get the nutrition you need throughout your pregnancy.

The Ultrasound: Ready for That First Close-Up

Thanks to relatively modern technology, your baby may have her picture taken this month. In addition to stirring up some powerful parental emotions, the ultrasound can reveal some exciting developments in your baby. You may be able to see four beating chambers in her heart, plus her limbs, fingers and toes You will also be shown her central nervous system, brain and spinal cord. And if you can't stand the suspense, this ultrasound can usually reveal if you're having a boy or a girl.

It's Fuzzy, but It's a Start

Your baby's visual cortex is busy forming some of the 100 million neurons that signal the start of visual development. This process continues after your baby's birth. Things will start out looking fuzzy for a while, gradually becoming sharp and clear. It's important to be sure your baby is getting nutrients like DHA through your diet, to help support this visual development.

Lanugo: Your Baby's First Hairdo

This month and next, your baby's hair will begin to grow. It will grow in the usual places like eyebrows and head. But she'll also start growing soft, downy hair called lanugo on her body and face. But don't worry. Lanugo disappears before birth, or during the first weeks of her life. And by the way, even if your daughter is born with a head of curly blonde hair, you might still end up with a straight-haired brunette on your hands.

Healthy Hints: Month 4

Remember to breathe.

Your body needs rest during pregnancy, even if it's just a few minutes a day. Take deep, slow breaths. Sit in a quiet room. Play soft music. Focus on tension areas. Let yourself relax.