Your baby measures 4.6 in (11.6 cm) from crown to rump and weighs 3.5 oz (100 g).

Sebastian Kaulitzki / Adobe Stock

Pregnancy Facts - Week 16

What's happening in week 16 of pregnancy

Your baby's umbilical cord has grown thicker over the weeks. Within the cord are two arteries pumping fresh blood to your baby and one vein carrying deoxygenated blood back to your body for a fill up. The umbilical cord is covered in a jelly-like substance that makes it slippery and less likely to catch on your baby's movements in the womb.


Your body has been continuously increasing blood production to keep up with your growing baby. As more blood is circulating through your body, you may find that your skin, especially on your face, having a little more color. A pregnancy glow, if you will.


How big is your baby in week 16 of pregnancy

Like it says at the top of the page, your baby measures 4.6 inches (11.6 centimeters) and weighs 3.5 ounces (100 grams).

Your baby's development in week 16 of pregnancy

Your baby's skin is developing this week. It's so think right now, you can actually see through it.

Hair is starting to grow on your baby's head, as are eyebrows and eyelashes.


This week, most of the cartilage in your baby's body has hardened into bone. This is an important step in helping your baby develop neck and back muscles. With the development of bone, you may actually feel your baby's kicks as early as this week. For most moms-to-be, especially first timers, it could take several more weeks before you realize a kick is actually a kick. It's easy to mistake the feeling as a stomach flutter or even gas moving through you.


The tiny bones in the ear canal of your baby are also starting to develop. These are the bones that translate ear drum vibrations for the brain to process. Your baby may actually be able to hear the sound of your voice this week. Granted, your baby won't understand, but your baby's listening.

Hearing your baby's heartbeat

Are you there baby? It's me, mommy. Amazon

There's something soothing about hearing a heartbeat, moreso your baby's heartbeat. At week 16 of pregnancy, your baby's heartbeat should be strong enough to hear with a sound amplification device like the Summer Infant Digital Pre-Natal System. It's a fun way to connect with your baby without having to go to the obstetrician just to hear the sound of your baby.

My baby 4.6 in (11.6 cm) from crown to rump and weighs 3.5 oz (100 g)