At week 20, your baby's length is about 6.5 inches (16.5 centimeters) from crown to rump (starting next week, measurements will be crown to heel). Your baby weighs about 10 ounces, and sticky white stuff is still covering your baby's skin.
Your stomach is now growing at about a centimeter a week, and the top of your uterus is approximately level with your belly button. Your baby's genitals are fully formed by this week, which makes it the perfect time to find out the sex, if you want to. He or she is also beginning to swallow, which you might even be able to witness it if you get an ultrasound. The development of swallowing means that your baby is ingesting some of the stuff that's floating around in the womb, which your baby's body will turn into meconium. This nearly tarlike, dark greenish-black substance will make up your baby's first few bowel movements (don't be shocked when you see that in a diaper!).
Around 20 weeks, your care provider may be able to hear your baby's heartbeat without having to squirt that gel on your belly. A DeLee fetal stethoscope can now do the job. Soon enough, family and friends might be able to hear the heartbeat just by putting their ears to your belly. On the next page, we'll talk more about this development and some other pointers for you and your partner.