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. Meanwhile, 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


Stay Calm Mom: "I'm Pregnant"– Real Women Share Their Stories

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, baby weighs around 3 3/4 pounds (1,707 grams).


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 at approximately 6 to 15 times an hour (compared to adults, who blink 19–20 times per minute).


As the lungs continue 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.

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 a 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. And if you have already been feeling them, they may be getting stronger. Unlike honest-to-goodness 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.

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, try using this time before baby arrives to weigh your feeding options and decide what feels best for you and your family.

Concerns About Leaking

It can be shocking or scary to notice 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:

  • 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.
  • You can wear a tissue or nursing breast pad in your bra to prevent stains.
  • 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.

Consider Your Feeding Options

It’s a good bet that you’ve been mulling over your baby-feeding options for a long while now. In addition to reading up on breast and bottle feeding, ask your healthcare provider, a lactation consultant, and friends and family who are seasoned moms about the pros and cons of different methods. Don't hesitate to ask lots of questions like:

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 everything over with mom-to-be, use your words wisely. Tread carefully in conversations about feeding methods. Instead of asking, "Are you planning on breastfeeding?", for example, try, "How do you think we should feed our baby?"

Upcoming Doctor's Visits

You’ll likely be back at your doctor or midwife'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 may offer you the whooping cough (pertussis) vaccine, also called Tdap, between 27 and 36 weeks.

If you fall into a high-risk category, beginning next week your doctor may schedule prenatal tests such as:

Special Considerations

Amniotic fluid is the liquid that surrounds and protects your baby inside your womb. The amount of amniotic fluid increases over the course of your pregnancy. Around week 34, however, 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's an issue or possibly cause an issue.


A low level of amniotic fluid is a condition known as oligohydramnios; the condition 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—or no known cause. You may not have any symptoms, but your doctor 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 healthcare provider will measure the amount of amniotic fluid via 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.


The opposite of too little amniotic fluid is too much amniotic fluid. An excess of amniotic fluid is called polyhydramnios, and it is seen in about 1% of pregnancies.

Polyhydramnios can arise from carrying more than one baby, having gestational diabetes, or having a baby with a birth disorder. If you have polyhydramnios, you may be measuring larger than expected and you may have symptoms that go along with that such as shortness of breath, abdominal discomfort, and pressure on your pelvic area.

Your doctor may discover polyhydramnios through a routine ultrasound. This condition most often occurs in the last trimester and generally results in no harm to the mother or baby. If it’s a concern for you, your healthcare provider will likely just have you come in more often for monitoring. 

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—some of which may be helpful, while others less so. Do your research and seek advice from trusted sources like your doctor, pediatrician, and close family and friends, but don't forget that 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.