What's happening with your baby at 31 weeks
At 31 weeks, your baby is about 41 cm long from head to heel and weighs around 1.5 kg (roughly 3.3 lb) — similar in size to a coconut. Weight gain is speeding up now, and most babies add close to half a pound a week from here to delivery.
Your baby's brain is developing quickly, forming new grooves and folds to make room for more tissue. All five senses are working now — baby can register light and dark through closed eyelids, hear sounds from outside the womb, and may respond to familiar voices.
Movements are becoming more coordinated — stretches, rolls, and the odd rhythmic hiccup you might feel as a small twitch. There's less room to move freely now, so kicks can feel different than they did a month ago, but you should still notice regular activity every day.
Common symptoms at 31 weeks
Shortness of breath, heartburn, and swelling in your feet and ankles are all common at 31 weeks as your uterus presses up on your diaphragm and stomach. Frequent bathroom trips usually continue as baby's weight adds pressure on your bladder.
Braxton Hicks contractions — irregular, painless tightening of the uterus — can feel more noticeable now. They usually settle with water and a change of position; contractions that become regular or painful are different and worth calling your provider about.
Sleep can be harder to come by at this stage. An active baby at night, restless legs, and trouble finding a comfortable position are all typical. Side-sleeping with a pillow between your knees and one supporting your bump tends to help most.
How often are prenatal appointments at 31 weeks?
Most providers move to appointments every two weeks starting somewhere between 30 and 32 weeks, then weekly closer to your due date. Expect your blood pressure, urine, weight, and baby's heart rate to be checked at each visit, along with a measurement of your bump (fundal height).
This is a good stretch to bring up any questions about labor, pain relief options, or your birth preferences. It's also a natural point to confirm your plan for reaching your provider outside regular office hours.
What to do this week
If you haven't started thinking about your hospital bag, now's a reasonable time to make a rough list — even if you don't pack it for a few more weeks. Comfortable clothes, toiletries, a phone charger, and baby's going-home outfit are the basics most people include.
If you're planning to take a childbirth or breastfeeding class, this is a good window to schedule it — classes fill up and you'll want time to fit in more than one. It's also worth starting conversations with your workplace about maternity leave logistics if you haven't already.
When to call your provider
A noticeable drop in your baby's movement is one of the most important things to act on. Try a kick count — you should feel around 10 distinct movements within 2 hours — and call your provider if movement doesn't pick up.
Call the same day for vaginal bleeding, a severe headache with vision changes, sudden swelling (especially in your face or hands), severe abdominal pain, or fluid leaking that could be your waters breaking. Regular contractions before 37 weeks need to be checked for preterm labor.