31 weeks pregnant: symptoms and baby development
Somersaults, and learning your voice.
Third trimesterMonth 75 min read
By Solesia, from public clinical guidanceUpdated
Your bump goes tight, holds for half a minute, and lets go. It does not hurt, and it does not come back on any schedule, and it is your uterus rehearsing: the practice contractions often begin around now. Inside, this is one of the liveliest weeks of all. Your baby is at the peak of their acrobatics, turning somersaults, sucking their fingers and, for the first time, picking your voice out from the wash of sound around them. Talk to them if you like; they are listening. The bump is growing faster than ever, and the weeks left can now be counted on two hands.
How big is your baby at 31 weeks
About the size of a coconut
16.2 in long·3.8 lb
Baby development at 31 weeks
At 31 weeks your baby measures about 16.2 inches from head to heel and weighs around 3.8 pounds, roughly a coconut. They are very active: turning, stretching, sucking a thumb or fingers, and now and then flipping right over. Fat is filling out the folds in their skin, and they look less wrinkled every week.
Their hearing has sharpened to the point where they can tell your voice from other voices, and studies suggest they will recognize it after birth. Talking, reading and singing to your bump is not silly; it is the first thing they learn. Loud, sudden noises may still make them jump.
They are swallowing amniotic fluid and passing urine into it, and the volume of fluid around them is at its highest about now. Their eyes open and close in something like a sleep-and-wake cycle, and you may notice long quiet stretches when they are asleep. Many babies are settling head down this week; some are still upright, and there is time.
Your body at 31 weeks
Braxton Hicks contractions are expected from about now, if you have not felt them already. Your bump goes hard and tight for twenty or thirty seconds, then softens. They do not hurt, they come at random, and they often show up after exercise, when your bladder is full, or in the evening. Changing position, a glass of water and a short rest usually settle them. They are practice, and they do not mean labor is near.
Your bump is growing quickly now, and the skin over it may itch as it stretches. That is expected. A fragrance-free moisturizer and loose cotton clothes help, and stretch marks, if they come, fade to silver after birth. If itching is intense and on your palms and soles, mention it at your next visit.
Sleep is still awkward. Lying on your side with a pillow under the bump, one between your knees and one behind your back keeps you comfortable and keeps you off your back. Many women find a nap in the afternoon does more than an extra hour in the morning.
Common pregnancy symptoms at 31 weeks
- Braxton Hicks. The uterus practicing. Painless and irregular; change position, drink water, and they pass.
- Itchy bump. Skin stretching over a fast-growing uterus. Moisturizer and loose cotton.
- Trouble sleeping. A big bump, a busy bladder, a busy baby. Pillows under the bump and between your knees.
- Round ligament pain. A sharp pull at the side of your bump on sudden moves. Turn and stand slowly.
- Swollen hands and feet. Fluid gathering by evening. Feet up, and take rings off before they get tight.
- Backache. Weight in front, looser joints. Supported sitting and a warm bath in the evening.
- Greasy or spotty skin. Hormones raising oil production. A gentle wash; it clears after birth.
When to call your provider at 31 weeks
Tightenings that become painful, or start coming at regular intervals, are worth a call to your provider or maternity unit.
Two things are worth a same-day call at any point in pregnancy: bleeding that is more than spotting, and pain that is severe or does not ease. From the second trimester, add fluid leaking and any change in your baby’s usual pattern of movement. You do not need to be sure something is wrong to call; that is what the number is for.
What to do at 31 weeks
- How you plan to feed. Breast, formula or both: there is no wrong answer, and knowing what you want lets the hospital help you from the first hour. A prenatal breastfeeding class is worth it if you plan to nurse.
- Prenatal visit. Every two weeks now. Your provider feels your bump to check which way your baby is lying, and there is time to ask about the practice contractions.
- Car seat and carrier. If you are buying a baby carrier or sling, choose one that keeps the baby upright, face visible and close enough to kiss. The car seat has to be installed before you leave the hospital.
- Tdap window. The whooping cough shot is given between 27 and 36 weeks. If it has not happened yet, ask for it at this visit or the next.
Common questions at 31 weeks
What do Braxton Hicks feel like at 31 weeks?
A tightening across your bump that lasts twenty to thirty seconds and then lets go. Your belly feels hard to the touch during one. They do not hurt, they do not come at regular intervals, and they stop if you move around or rest. Real contractions build in strength and come closer together.
Can my baby hear me at 31 weeks?
Yes, and by now they can tell your voice from others. Sound reaches them muffled through your body, with your voice carried best of all. Talking and singing to your bump helps them know you when they arrive; there is no need to make a project of it.
Is it normal for my baby to be breech at 31 weeks?
Yes. Many babies are still head up or sideways at 31 weeks, and the large majority turn on their own over the next few weeks. Your provider checks position at each visit, and nothing needs deciding before about 36 weeks.
How many months is 31 weeks?
About seven months, near the end of the seventh. You are in the third trimester with nine weeks to your due date. If the count seems off, it is because a month is about four and a half weeks, so forty weeks fits into nine months even though four times nine is thirty-six.
Written from public clinical guidance, including NHS: Week 31, ACOG: How your baby grows, ACOG: Changes in your body, ACOG: The Tdap vaccine and pregnancy, ACOG: Skin changes, NHS: Itching and NHS: Stomach pain. This page is general information, not medical advice, and does not replace your provider.