39 Week Old Baby Development

Learn everything you need to know about your 39 week old baby. Track important developments and milestones such as talking, walking, growth, memory & more.

By Parents Editors

Published on June 14, 2017

mother laying on bed balancing baby son on legs — Photo: Getty Images/ JGI/Jamie Grill

Your Growing Baby

Increasing Physical Skills

The first time your baby pulls herself up is a thrill for both of you—and perhaps a bit of a surprise, too, since one minute your baby was grabbing the edge of the table, the next she's at eye level with it. But it won't take her long to figure out that now that she's standing up, the most interesting thing she can do is to cruise, or sidle along the edge of the furniture while holding on to it for support. She might go cautiously at first, but as she gains confidence, strength, and skill, she'll pick up speed, and you'll understand why they call it "cruising."

Of course, some babies go straight from crawling to walking, while others pull themselves up, then want to grab onto your hand as a built-in support. No matter how your baby gets to walking, you can increase her confidence by cheering her on—and laughing when she falls down, so it won't upset her too much. Another great way to help baby learn physical coordination—along with memory and other important skills—is by playing a few classic baby games.

Playing with Your Baby

Another great way to help baby learn physical coordination—along with memory and other important skills—is by playing a few classic baby games. Some good ones to start now:

So Big: Ask your baby, "How big is (Sophie)?" Then hold up your arms for her to imitate and answer, "Soooo big." It's a big hit with most babies.
Itsy-Bitsy Spider: Teach your little one to do the hand gestures—the wiggly spider moving up the water spout—as you sing the song, since it will help her learn to coordinate her hands and fingers.
This Little Piggy: The funny toe-tickling game teaches Baby about her body.
Pattycake: Help her cycle through the motions of the baker baking a cake; the game will help her see the difference between your hands and hers.

Health and Safety Info

Baby's Expanding Menu

Table for three? By now, mealtimes in your house are becoming real family events, since your baby's old enough to sample most of what you're having for dinner, including chicken, pizza, and spaghetti, as long as it's cut into super-small pieces and not too hot or painfully spicy. As your baby's diet changes to include a wider variety of foods, and as she drinks less breast milk and formula, you might worry that your baby's not getting all the nutrition she needs. In fact, some older babies do develop vitamin and mineral deficiencies, including anemia, a condition that indicates a lack of the dietary iron that produces hemoglobin.

Is It Anemia? What to Look For

Some signs of anemia include paleness, weakness, irritability, even rapid heart rate or shortness of breath. Your pediatrician will be on the lookout for anemia at well-baby checkups, so talk to her if you have any concerns about what your child's eating and ask whether an iron supplement might be necessary. But if you're concerned, add iron to your baby's diet in the form of fortified cereal and pasta and naturally iron-rich foods, such as lean meats, egg yolks, and leafy green veggies. Vitamin C-rich foods, such as avocado or small amounts of diluted orange juice, which you can serve in a sippy cup now, also help baby absorb iron better.

Learn More About Infant Amenia

Must-Knows

Conquering Back Pain

Even if you avoided the curse of sciatica during your pregnancy, you might find yourself prone to back pain now. Why? For starters, your once-tiny newborn is a lot bigger now; at 9 months, she's probably more than doubled her birth weight. Suddenly, scooping her up and carrying her all the time takes a toll on your back muscles. And now that she's starting to walk, you'll spend a lot of time hunched over, holding your baby's hand as she toddles along. There are certainly worse ways to wind up with back pain, but if you find that you're hurting more often than you have before, talk to your doctor.

In the meantime, you can stave off back injuries with a few simple routines:

When you pick up your baby (or a laundry basket, or a forgotten toy), bend at your knees and lift with your legs, instead of bending at your waist and doing most of the lifting with your arms, which strains back muscles.
Slide the side of your baby's crib down before you put her in or lift her out. It's an extra step, but you'll avoid the awkward lifting angles that could hurt your back.
Set aside a few minutes to do crunches and other abdominal exercises several times a week. When your core's strong, it supports your back too. Bonus: You'll help flatten and tone your belly in the process.