Your pregnancy: weeks 17 to 20

Your baby

Your baby is growing quickly now, about an inch every month. At 18 weeks, your baby will be around 8 inches long and weigh about 8 ounces. The umbilical cord that connects you and your baby is thickening and continues to carry blood and nutrients.

You’ll probably have an ultrasound appointment with us at this stage. We’ll see how you’re feeling, check on your little one’s development, and say “hi” to your baby via ultrasound. Around week 20, we’ll be able to tell you the reproductive anatomy of your baby — unless you want it to be a surprise!

What’s happening this week?

Your body

Can you feel your baby moving? Those first flutters are called “quickening,” and some people say they feel like butterflies.

Don’t panic if you notice dark patches on your face. They’re from the extra estrogen your body is producing and should lighten after pregnancy. Just be sure to use sunscreen to prevent the patches from darkening in the sun. (Actually, sunscreen’s always a good idea.) You may also see a narrow, dark line running from your belly button to the top of your pubic bone. All these changes are normal signs that your pregnancy is on track.

Your to-do list

  • Schedule an appointment with us between weeks 16 and 20. We’ll measure your baby’s growth and development and get a better sense of your due date.
  • If you’re a Kaiser Permanente member, make sure you’re registered on kp.org so you can email your doctor with questions, keep track of your prenatal appointments, and more online.
  • Download our pregnancy and childbirth podcast — guided meditation to support you during pregnancy and help prepare you for childbirth.
  • Decide whether you and your partner want to hire a personal labor coach (doula).
  • Prepare for your baby’s birth by taking a class.*
  • If you plan to go back to work, start thinking about child care.

*Some classes may require a fee.

Ready to get maternity care?
Find a hospital or care provider near you.