Your baby is the size of a coconut

31 Weeks Pregnant: Your Baby's Development

Now that you are 31 weeks pregnant, it's good to know what's going on with your baby's development inside the womb. Most of your baby's bones are hardening, but the bones on her skull remain soft and flexible, making it easier for her to pass through the birth canal when the time comes. At birth, your baby will have soft spots on her skull, called fontanelles: One will close a few months after your baby is born, while the other will close at about 18 months of age or later.

More developments inside the womb at 31 weeks pregnant: Your little one's brain is maturing rapidly. As a result, your baby may start to regulate her own body temperature, meaning she's no longer entirely reliant on the amniotic fluid for warmth.

You're not the only one who may have frequent urination! Your baby is swallowing amniotic fluid and peeing several cups back out each day.


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How Big Is Your Baby at 31 Weeks?

When you are 31 weeks pregnant, your baby is about the size of a coconut.

31 weeks pregnant

Mom's Body at 31 Weeks Pregnant

At 31 weeks, you could be 7 or 8 months pregnant (depending on how the weeks are divided into months) and you are well into the third trimester. You may be noticing some pregnancy-related changes to your breasts. For example, you may start to see reddish streaks on the skin—hello, stretch marks! There's nothing you can do to prevent stretch marks forming on your breasts, or elsewhere for that matter, but the striations may fade with time after you give birth. As the skin stretches over your growing breasts, you may also find the skin feels itchy. Applying moisturizer may help ease the itchiness. We'll cover this symptom in more detail below.

As your breasts grow, you may also find that you need to go up a bra size or two so that you get proper support. If you haven't already, head to your local maternity wear store or department store and ask for a professional maternity bra fitting. Maternity bras often have wider straps, more coverage in the cup, and extra rows of bra hooks so you can adjust the size up as needed. Plus, you can continue using them after your baby is born! There are also nighttime maternity bras that provide extra support while you sleep, and maternity sports bras, too.

Later in the third trimester, your breasts may leak a thick, yellowish fluid called colostrum. Not all moms-to-be experience this leakage, but, if you do, you can tuck a gauze pad or a nursing pad into your bra to absorb the colostrum. Once your baby is born, if you choose to breastfeed, colostrum provides your baby with nourishing proteins and antibodies. Colostrum is produced for a few days before breast milk starts flowing.

31 Weeks Pregnant: Your Symptoms

  • Hand pain. You may experience what's called carpal tunnel syndrome. This is when the tissues swell in your hands and press on the nerves, causing a tingling sensation or a numbness in your hands. Typically, once you give birth and the swelling goes down, these symptoms will go away. For now, using a wrist splint and resting your hands throughout the day might help. Mention this symptom to your healthcare provider for further guidance on how to ease the discomfort.

  • Discomfort from baby's movements. Sometimes it can also be downright uncomfortable to be kicked and jabbed by your active little one. On the other hand, feeling your baby move is reassuring, and around now your provider may recommend that you monitor your baby's movements by doing daily "kick counts." Download our handy tracker and earn more about this process here.

  • Feeling exhausted. It's normal to be tired around this time—after all, your body is working hard to create a new life. In addition, your fatigue might be compounded by the fact that you're finding it harder to get a good night's sleep. Try to take naps when you can throughout the day. Eating well and exercising may also give you a little energy boost. Always speak to your healthcare provider if you're at all concerned about how tired you are.

  • Itchy skin. As your belly grows, it's not uncommon to have an itchy abdomen at around 31 weeks pregnant. You might also experience itchiness elsewhere, like around your breasts and buttocks. Try to ease the discomfort of itchy skin during pregnancy by using a soothing moisturizer, and be sure to drink lots of water.

31 Weeks Pregnant: Things to Consider

  • As your belly grows, you may be struggling to find a comfortable sleeping position. Experts recommend lying on your side with one or both knees bent. You could also place one pillow between your knees and another under your belly, or go for one of those full-length pregnancy pillows for added comfort.

  • You may be wondering if sex during pregnancy is safe now that your belly is getting bigger. If your pregnancy is normal and both you and your partner feel comfortable, it is safe to have sex even in the third trimester. Finding a comfortable position may take a little time, but experiment and find out what works for you. Ask your healthcare provider if you're at all worried about sex or have any questions.

  • Now could be a good time to start to think about whether you plan to breastfeed or formula feed. Talk to your healthcare provider or lactation consultant about your choice, and ask any questions you may have. If you plan to breastfeed, you might also like to attend lactation classes. If you're unsure, your provider will be able to talk you through any equipment you may need to get, like a breast bump and bottles, and where to buy them. If you plan to formula feed, you can also ask for advice on what formula might be best for your baby. You still have time to figure this out, and you may only decide what works for you once your baby is born, but it can't hurt to give this topic some thought.

31 Weeks Pregnant: Ask Your Doctor

  • Are there any extra nutrients I might need at this stage of pregnancy?

  • What is the risk of my baby being born prematurely?

  • Who can I call if I'm concerned about anything after your work hours?

  • When should I stop working? Is there anything I should or shouldn't do at work at this stage?

  • How can I fasten my seatbelt now that my belly is so big?

  • At 31 weeks pregnant, what symptoms should I not ignore? Although your healthcare provider is best-placed to answer this question, this article covers some of the warning signs you should not ignore during pregnancy.

How we wrote this article
The information in this article is based on the expert advice found in trusted medical and government sources, such as the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists.
The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.

31 Weeks Pregnant: Your Checklist

  • Decide who you would like to be with you for support during labour. It could be a doula—a non-medical professional who can give you emotional and practical support during labour and childbirth—or it could be your partner, best friend, or family member.

  • Although you may have already discussed maternity leave with your employer, now could be a good time to revisit your plans and start to share your workload with your colleagues so that crucial tasks aren’t left to the last minute.

  • Sign up for even more pregnancy tips here: