Your baby this week
Your baby now weighs about three and a third pounds — a kilo and a half — and stretches around sixteen inches long: about the size of a coconut. And what a week for the senses. Your baby's ears are well developed, and the world sounds like life under water — muffled, rhythmic, and dominated by you: your voice, your heartbeat, your digestion providing the percussion section. Babies this age can respond to familiar voices and music with movement, and after birth, many newborns visibly calm at the sound of the voice they've been listening to for months. Keep talking, singing, and reading out loud if you enjoy it — your baby is in the audience.
Sight is developing too: the pupils can widen and narrow in response to light, even in the gentle dark of the womb. Taste and smell are quietly online — flavors from your meals pass into the amniotic fluid, and your baby swallows that fluid daily, getting a preview of the family menu. Touch is perhaps the most practiced sense of all: your baby can grasp, explore their own face and cord, and turn their head from side to side — yes, head-turning is a genuine new skill this week, powered by a strengthening neck.
Under the scenes, the big story is growth. From around now, your baby's main job becomes gaining weight — roughly half a pound a week in the coming stretch — laying down the fat stores that will regulate temperature and provide energy after birth. The lungs and digestive system continue maturing, the brain keeps building connections at remarkable speed, and your baby's sleep cycles grow more organized, with quiet sleep and active sleep — and those REM dream periods — taking turns.
Space is getting snugger, too: full somersaults are harder now, so movements increasingly feel like strong rolls, stretches, and pushes rather than flips. The intensity should stay; the style is simply changing with the real estate.
Two more week-31 details worth a spotlight. First, hiccups: those small, rhythmic, repeated jumps you may feel for minutes at a time are a normal part of this stage — many doctors connect them with the same swallowing and breathing practice we've been celebrating, and they are not a distress signal. Second, your baby's skull bones remain soft and separate, with the soft spots you'll one day feel on your newborn's head already part of the design — flexibility for the birth journey now, and room for that fast-growing brain afterward. Even the bones, at week 31, are thinking ahead.
Your body & symptoms: the crowded stage
Which brings us to your side. The headline of week 31, for many moms, is breath. Your uterus is now high enough to press up against your diaphragm, and there is simply less room for a deep breath. Feeling short of breath walking, talking, or climbing stairs is extremely common at this stage — your body is compensating, your blood is carrying oxygen efficiently for two, and your baby is getting what they need. Slow down, sit tall, and let tasks take the time they take. As always, though, sudden or severe breathlessness is a different story — that's on our call list below, and it always earns a call.
Also in the week-31 lineup: heartburn, especially after evening meals; back and pelvic aches; Braxton Hicks contractions — hold that thought, they're our next segment; leg cramps and restless legs at night; mild swelling; frequent bathroom trips; and leaking colostrum for some moms, as your body previews the first food. Sleep often comes in installments now, and the vivid dreams many women report in late pregnancy can make those installments feel like a film festival.
Emotionally, this is often a week of lists: the nursery list, the hospital-bag list, the people-to-tell list. Nesting energy may surge and crash in the same afternoon. Ride it kindly — small tasks, frequent rests, and the reminder that the baby needs a safe place to sleep and a fed, rested-ish mother far more than a color-coordinated closet.
Completing the week-31 roster: swelling that builds through the day and eases overnight; tingling fingers for some moms, from fluid in the tight spaces of the wrist; skin that stretches, itches, and occasionally surprises you with new moles or darker patches — common in pregnancy, and anything rapidly changing is worth showing your doctor; and a sense of balance that has officially relocated. Handrails are not surrender. They are strategy, and so is sitting down to put on shoes.
Braxton Hicks vs real contractions: the field guide
Now, the question echoing through every third-trimester household: is that a real contraction? Let's decode the two kinds. Braxton Hicks — the practice contractions — have usually been visiting since mid-pregnancy, but they get more noticeable now. Their personality: irregular, unpredictable, and they don't build a pattern. They often feel like a general tightening across the front of your belly, they're usually more uncomfortable than painful, and — their signature move — they ease off or stop when you change position, get up and walk, rest, or drink some water. They're your uterus rehearsing, the way a band tunes up before the concert. They do not, by themselves, mean labor is starting.
Real labor contractions have a different character. They come at regular intervals and gradually get closer together. They grow stronger and longer over time rather than fading. Movement doesn't stop them — walking may actually make them more purposeful. The sensation often starts in the back and wraps around to the front, and it builds in intensity in a way that eventually makes talking through one difficult.
A simple home test many doctors suggest for a confusing spell: hydrate, rest or change position, and watch the clock for an hour or so. Practice contractions usually scatter; real ones organize. But here's the part to carry with you: before 37 weeks, regular contractions that keep coming are always worth a call, even if you're unsure — preterm labor is exactly the situation where your team wants to hear from you early, when there's the most they can do. And at any point, if you're in doubt, call. “I'm not sure if these are real” is a completely legitimate reason; it's what the phone number is for.
When you do time a spell, keep it simple: note when each contraction starts and how long it lasts. Many doctors offer a rough rhythm to watch for once you're full term — contractions about five minutes apart, lasting about a minute each, continuing for about an hour — but every practice sets its own “time to call, time to come in” guidance, and yours may differ, especially with a first baby or a long drive to the hospital. So the field guide's real final page is this: learn your own doctor's numbers at your next visit, write them on the fridge, and let clockwork doubt always end in a phone call, never in silent guessing.
Short of breath, and other crowded-neighborhood notes
A few more comfort notes for the crowded stage. For everyday breathlessness: smaller meals help, because a full stomach competes with your lungs; good posture gives the diaphragm its full range; and many moms find propping themselves slightly at night more comfortable. Heartburn answers to the same smaller-meals logic, plus staying upright a while after eating.
For the aches: keep changing position, keep the pillow village at night, and take walks in the cool of the day if you can — movement genuinely helps circulation, swelling, and mood.
And keep counting those movements in your baby's usual active times — by week 31 you know the rhythm like a favorite song. About ten movements in up to two hours is a common general guideline if counting is your method, but your baby's pattern is the true north; any clear decrease or change earns a same-day call, as always.
And one small wardrobe note for the crowded stage, because week 31 is when it starts to matter: supportive, well-fitting shoes and a properly fitted bra do more for back and rib comfort than most gadgets on the market. Your ribcage is literally expanding and your feet are carrying a new distribution of weight; dressing the body you have this month — rather than the one from month three — is not indulgence. It's ergonomics, and you deserve ergonomics.