Week 31 of Your Pregnancy

Pregnancy Week by Week: Week 31

Verywell / Bailey Mariner

In This Article

At 31 weeks pregnant, your baby is practicing some of the skills they'll need after birth like blinking and breathing. Your body may be practicing, too—with Braxon Hicks contractions and possibly some leaking colostrum.

31 Weeks Pregnant Is How Many Months? 7 months and 3 weeks

Which Trimester? Third trimester

How Many Weeks to Go? 9 weeks

Your Baby's Development at 31 Weeks

At 31 weeks, a baby is more than 11 inches (28.3 centimeters) from the top of their head to the bottom of their buttocks (known as the crown-rump length), and baby's height is about 15 3/4 inches (40.3 centimeters) from the top of their head to their heel (crown-heel length). This week, the baby weighs around 3 3/4 pounds (1,707 grams).

At 31 weeks pregnant, your baby is about the length of a burp cloth
Verywell / Bailey Mariner

Eyes

As early as 31 weeks, ultrasound can pick up the tiny movements of your baby's eyelids blinking. Research shows that babies at 31 weeks blink very slowly—approximately 6 to 15 times an hour (compared to adults, who blink 19–20 times per minute).

Lungs

As the lungs continue to mature, your baby is still working on those breathing skills. Breathing movements increase from 10% to 20% at 28 weeks to 30% to 40% after 30 weeks.

Survival Outside the Womb

At 31 weeks, a baby is in the last week of the very preterm category. With each week that a baby completes in utero, the chances of survival without disabilities related to prematurity get better. Babies will still require special care in the NICU for at least a few weeks, but at 31 weeks, the rate of survival is up to 99%.

Explore a few of your baby's week 31 milestones in this interactive experience.

Stay Calm Mom: Episode 7

Watch all episodes of our Stay Calm Mom video series and follow along as our host Tiffany Small talks to a diverse group of women and top doctors to get real answers to the biggest pregnancy questions.

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Your Common Symptoms This Week

Whether you are planning to breastfeed or not, at 31 weeks pregnant, your breasts are getting ready. In fact, you may have even noticed either a creamy, yellowish, or thin, watery substance occasionally leaking from your nipples. Your uterus is also likely getting ready for labor with some practice contractions.

Leaky Breasts

During pregnancy, your breasts grow and prepare to make milk for your baby. You begin to make a very small amount of the first milk, known as colostrum, as early as week 16. It can even begin to leak out of your nipples in the second trimester, but it's more common to see leaking during the third trimester.

What Experts Say

"About half of all pregnant women will experience this type of leakage in the third trimester. Whether your breasts leak colostrum or not in no way reflects your body’s ability to produce breast milk."

—Allison Hill, MD, OB/GYN

Braxton Hicks

If you haven't already experienced the occasional tightening of your uterine muscles, you may begin to feel them now. If you have been feeling them, they might start getting stronger. Unlike effective contractions, Braxton Hicks are irregular, go away with activity, and do not move closer together or increase in intensity. Take these dry runs as opportunities to practice some of the breathing and coping mechanisms you’ve learned in birthing class.

Be sure to discuss any increase in uterine contractions with your provider.

Self-Care Tips

How you plan to feed your baby is a personal decision. Just like you've considered your birth preferences to share with your provider and birth support team, use the time before the baby arrives to weigh feeding options and decide what feels best for you and your family.

Concerns About Leaking

It can be shocking or scary to notice a discharge from your nipples when you aren't expecting it, but a small amount of leakage during pregnancy is normal. Here's what you need to know:

  • A small amount of colostrum may leak during sexual activity, and it's normal.
  • Not all expecting mothers leak colostrum, so you shouldn't worry if don't see it; a lack of leakage doesn't mean that your breasts aren't getting ready to make breast milk—they are!
  • While a small amount of white or yellow discharge is normal, you should always feel comfortable calling your doctor to discuss any changes that concern you.
  • You can wear a tissue or nursing breast pad in your bra to prevent stains.
  • You don't make a large amount of colostrum, so if you experience leaking during pregnancy, you may only notice a drop or two or a stain on your bra.

Consider Your Feeding Options

It’s a good bet that you’ve been mulling over your baby-feeding options for a while now. In addition to reading up on breast and bottle feeding, ask your provider, a lactation consultant, a well as friends and family about the pros and cons of different methods. Questions you can ask include:

Hearing a wide range of perspectives and experiences can help you determine what you’d like to do. As you near your expected due date, you'll also want to:

Your Week 31 Checklist

  • Take the opportunity to practice childbirth breathing during Braxton-Hicks contractions.
  • Engage in some safe physical activity that you enjoy.
  • Talk to a lactation professional and other moms to learn more about feeding options and support.
  • Discuss your feelings about feeding your child with your partner.
  • Talk to your doctor about any symptoms that concern you.

Advice for Partners

Exploring feeding options with your partner can be one of the more stressful aspects of transitioning to parenthood.

What Experts Say

“When considering feeding options, it's important for you both to assess, in an ongoing way, what you each expect to do, and, ultimately, what is realistic for you and your new baby. Often, parental stress happens when there’s a gap between expectations and reality. Even a simple, well-intended question, like, 'Are you planning on breastfeeding?' can be a loaded one."

—Shara Marrero Brofman, PsyD

When talking about these decisions, use your words wisely. Tread carefully in conversations about feeding methods. Instead of asking, "Are you planning on breastfeeding?" ask, "How do you think we should feed our baby?"

Upcoming Doctor's Visits

You’ll likely be back at your provider's office again next week for another prenatal checkup. For the most part, it will be the same old routine.

In addition to the usual checks, your provider might offer the whooping cough (pertussis) vaccine (also called Tdap) between 27 and 36 weeks.

If you fall into a high-risk category, your provider might schedule prenatal tests starting next week. These tests might include:

Special Considerations

Amniotic fluid is the liquid that surrounds and protects your baby inside the womb. The amount of amniotic fluid increases over the course of your pregnancy. Around week 34, the level reaches its peak at an average of 1 1/2 pints (800 milliliters). Too little or too much amniotic fluid can mean there is an issue—or can possibly cause an issue going forward.

Oligohydramnios

A low level of amniotic fluid (oligohydramnios) is a condition that occurs in 1% to 5% of pregnancies.

Oligohydramnios can be caused by leaking fluid at the end of pregnancy, a problem with the placenta, or an issue with the baby. It can also have no known cause. You may not have any symptoms, but your provider may suspect that your amniotic fluid is low if your bump or your baby appears smaller than expected at this stage of your pregnancy.

To diagnose this condition, your provider will measure the amount of amniotic fluid using an ultrasound. Your pregnancy will also likely be monitored closely and you may have to have additional tests such as a non-stress test and contraction stress test.

While low fluid can be a sign of fetal distress, it does not impact fetal outcomes in the majority of cases. However, it is possible that your provider might recommend you deliver a bit before your due date.

Polyhydramnios

The opposite of too little amniotic fluid is too much amniotic fluid. An excess of amniotic fluid (polyhydramnios) occurs in about 1% of pregnancies.

Polyhydramnios can happen if you are carrying more than one baby, have gestational diabetes, or have a baby with a birth defect. In some cases, the cause is not known.

If you have polyhydramnios, you might be measuring larger than expected and you may have symptoms such as shortness of breath, abdominal discomfort, and pressure on your pelvic area.

Your provider might discover polyhydramnios during a routine ultrasound. The condition most often occurs in the last trimester and generally doesn't harm you or the baby. If it’s at all a concern, your provider will likely just have you come in for monitoring more often.

A Word From Verywell

As a new parent, you'll have a lot of decisions to make—from which car seat to buy to how you're going to feed your baby. The people around you are going to have a lot of opinions—and not all of them will be helpful. Do your research and seek advice from trusted sources like your provider, pediatrician, and close family and friends. Don't forget: only you and your partner can decide what's best for you and your growing family.

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Article Sources
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Additional Reading
  • Allison Hill, MD. Email communication. October, November 2017.

  • Shara Marrero Brofman, PsyD. Email and Phone Communications. October, December 2017.