Our Baby Journey31 weeks pregnant
31 weeks pregnant is about 7 months. It falls in the seventh month of pregnancy. You are in week 31 of 40, in the third trimester. Here is what is happening with your baby and your body this week.
Your baby is about the size of a coconut.
Length: about 41.1 cm (16.2 in) from crown to heel · Weight: about 1.5 kg (3.3 lb)
Your baby at 31 weeks
The baby can turn its head from side to side. All five senses are working.
Your baby's brain is making connections at a remarkable pace this week. Nerve cells are linking up and the surface of the brain is becoming more folded, which gives it more room for the networks your baby will use to learn, see, and respond after birth.
With more fat building up under the skin, your baby is looking less thin and wrinkled and more like a newborn. The eyes can open and close, and your baby can tell light from dark, so a bright light on your belly may sometimes prompt a reaction. Sleep and wake cycles are becoming more organized, which is why you may notice regular busy periods and quieter stretches.
Space in your uterus is getting tighter, so you may feel more rolls, stretches, and firm pushes than sharp kicks. The pattern of movement is what matters, and it should stay strong. Babies vary widely in size at this stage, and your provider will track your baby's growth over time rather than at a single visit.
Your body at 31 weeks
You may leak a little colostrum (early breast milk). Braxton Hicks may be more frequent.
Your uterus now sits well above your belly button and presses up toward your ribs and diaphragm, so you may feel short of breath after climbing stairs or talking for a while. Sitting up straight and sleeping propped on pillows can help. Your growing bump also shifts your center of gravity, which can strain your lower back and make getting out of bed or a chair feel awkward. Some people notice tingling or numbness in their hands, caused by fluid pressing on nerves in the wrist. It usually eases after birth, but mention it to your doctor or midwife if it bothers you.
Your belly at week 31
In month 7 (weeks 28–31) your belly grows noticeably and may start to feel heavy. Stretch marks may appear. Fundal height is usually around 28–31 cm.
Belly size and shape vary a lot depending on your build, whether this is your first pregnancy, your baby's position and the amount of amniotic fluid. At checkups your doctor or midwife may measure your fundal height to track your baby's growth, and may arrange an ultrasound if the measurement is quite different from what they expect.
Symptoms at 31 weeks pregnant
- Shortness of breath when active or lying flat
- Lower back and pelvic aches
- Tingling or numbness in the hands
- Trouble finding a comfortable sleeping position
- Leg cramps, often at night
Checkups around week 31
Prenatal visits are usually every two weeks around this time, though schedules vary by country and by pregnancy. Your provider will typically check your blood pressure, urine, and the size of your bump (fundal height), and listen to your baby's heartbeat. Some people are offered a growth scan if there are concerns about the baby's size.
Tips for week 31
- Learn about breastfeeding and feeding options.
- Pack your hospital bag over the next few weeks.
- Plan your route to the hospital or birth center.
Common symptoms in the third trimester
The third trimester runs from week 28 until birth, usually around week 40. Your baby gains most of their weight, their lungs mature, and your body prepares for labor. Not everyone has every symptom, and it is normal for symptoms to come and go. Common ones include:
- Shortness of breath as your uterus presses up on your diaphragm
- Braxton Hicks (practice) contractions
- Swelling of the feet and ankles
- Trouble sleeping and getting comfortable
- Pelvic pressure and pain
- Needing to urinate more often again
- Heartburn and back ache
Read the full third trimester guide.
When to call your doctor or midwife
Contact your healthcare provider or maternity unit straight away, or get emergency care, if you have:
- Vaginal bleeding
- Severe or persistent abdominal pain or cramping
- A severe headache, blurred vision, or sudden swelling of your face, hands or feet
- A fever of 38°C (100.4°F) or higher
- Fluid leaking from your vagina
- Severe vomiting where you cannot keep fluids down
- Your baby moving less than usual or a change in their pattern of movements (later in pregnancy)
- Regular contractions before 37 weeks
- Pain or burning when you urinate
- Feeling very low, anxious, or having thoughts of harming yourself
Have a question about week 31?
Ask our AI pregnancy assistant about symptoms, nutrition, scans or anything else on your mind this week.
Frequently asked questions
How big is my baby at 31 weeks pregnant?
At 31 weeks pregnant, your baby is about the size of a coconut. That is about 41.1 cm (16.2 in) from crown to heel, weighing about 1.5 kg (3.3 lb).
How big is my belly at week 31 of pregnancy?
In month 7 (weeks 28–31) your belly grows noticeably and may start to feel heavy. Stretch marks may appear. Fundal height is usually around 28–31 cm. Bump size, shape and when you start to show vary a lot from person to person.
How much should my baby move at 31 weeks?
There is no single number that is right for every baby. What matters is getting to know your own baby's usual pattern of movements and noticing if it changes. Movements may feel more like rolls and pushes as space gets tighter, but they should not become less frequent. If you feel your baby is moving less than usual, contact your doctor, midwife, or maternity unit right away rather than waiting.
Is it normal to be short of breath at 31 weeks pregnant?
Yes, mild breathlessness is common now because your uterus is pushing up against your diaphragm and your body is working harder to supply oxygen to you and your baby. Slowing down, sitting upright, and propping yourself up at night can help. Breathlessness that comes on suddenly, is severe, or comes with chest pain, a cough, or a racing heartbeat needs urgent medical attention.
Can a baby survive if born at 31 weeks?
Babies born at 31 weeks are moderately preterm, and with care in a neonatal unit most do well. They usually need help with breathing, feeding, and keeping warm for several weeks before going home. The outlook depends on the baby's health and the care available. If you have signs of early labor, such as regular tightenings, fluid leaking, or bleeding, contact your provider or hospital immediately.
What trimester is 31 weeks pregnant?
Week 31 is in the third trimester, which covers weeks 28 to 40.
How many months is 31 weeks pregnant?
31 weeks pregnant is about 7 months. It falls in the seventh month of pregnancy. The seventh month covers weeks 28 to 31. Pregnancy is about 40 weeks, or roughly 9 months, counted from the first day of your last period.
This page is general educational information and is not a substitute for advice from your doctor or midwife. Every pregnancy is different, and baby sizes are approximate averages. Last updated 2026-11-07. See our medical disclaimer.