Your Weekly Pregnancy Development: Week 17

Air passages in your baby's lungs finish branching

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Week 17

Little lungs are getting ready for oxygen

Week 17: Your baby is getting ready for breathing and growing

Between the 17th week and 20th week of pregnancy, your baby’s lungs are getting close to being able to function, while layers of brown fat start to grow.

  • Right now, your baby is about 4-1/2 to 5-1/2 inches long, or about the length of a large orange.
  • Little hiccups continue, and you might feel them.
  • When you’re around 17 weeks pregnant, a necessary fat called brown fat develops under your baby's skin. This will help keep her warm after birth. Later in your pregnancy, your baby will develop additional layers of fat.
  • Air passages in your baby's lungs finish branching.
  • By your 17th week of pregnancy, your baby's lungs prepare to take in oxygen.

Week 17

Your week 17 nutrition and health

The nutrients you need to be eating, every day

As you know, eating a balanced diet with colorful, nutritious foods and taking a prenatal multivitamin significantly impact you and your baby's health.

During your 17th week of pregnancy, it’s important to continue boosting your pregnancy diet with these specific nutrients (be sure to check with your doctor before making any significant dietary changes):

  • Protein: lean beef, chicken, turkey, pork, beans, tofu
  • Iron: lean red meat, chicken, turkey, pork, fish, and whole-wheat breads that are fortified with iron
  • Calcium: Nonfat or low-fat milk, yogurt, cheese, and soy products that are fortified with calcium
  • Folic acid (folate): leafy green vegetables, broccoli, and breads and cereals that are fortified with folic acid
  • Vitamin A: citrus fruits, broccoli, bell peppers, strawberries, tomatoes, mangoes, potatoes with the skin
  • Vitamin C: orange juice, citrus fruits, bell peppers
  • Zinc: meat, seafood, dried beans, chickpeas, and breakfast cereals that are fortified with zinc


Week 17
Don't forget about vitamin B12

Vitamin B12 is an essential B vitamin involved in the formation of all body tissues. Vitamin B12 is important for correct genetic code replication in cells. Vitamin B12 is only found in foods of animal origin, so vegetarians should make sure they are getting sufficient amounts from food sources that are allowable under their dietary guidelines, or from proper supplementation.

The Recommended Daily Allowance (RDA) of vitamin B12 for pregnant women is 2.6 mcg, and 2.8 mcg during lactation.

Here is a list of common foods that contain vitamin B12:

Food: Amount: Vitamin B12 Amount:
Milk 8 oz 0.9 mcg
Yogurt 8 oz 0.9 mcg
Kellogg's® Special K®cereal 1 cup 6 mcg
Eggs 1 egg 0.5 mcg
RED STAR® Nutritional Yeast
Vegetarian Support Formula
~1 tablespoon 4 mcg

Women who do not consume meat or dairy foods should discuss with their health care professional the need for a supplemental source of vitamin B12 during pregnancy, such as a prenatal vitamin that contains 100% of the RDA for vitamin B12.

Find more foods rich in essential nutrients for your pregnancy.

Kellogg's Special K and Red Star Nutritional Yeast Vegetarian Support Formula are not trademarks of Abbott Laboratories.
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