Pregnancy Week 27: End of Second Trimester

Welcome to week 27 of pregnancy — a genuinely lovely milestone. This is the final week of your second trimester. Next week you cross into the third, and the countdown becomes a little more real. Take a beat to notice how far you've come: your bump, your baby, your body all doing quiet, extraordinary work.

Your baby this week is cauliflower-sized, about 2 pounds. Their brain activity is climbing, they're cycling through recognisable sleep and wake states, and they're becoming more responsive to sound, light and your voice. For you, week 27 often brings a slightly heavier, more tired feeling than a few weeks ago — the classic mid-pregnancy sweet spot begins to shift as your body preps for the third trimester's higher demands.

Below: what's happening for baby and you, how to eat and move well, what to bring to your next appointment, and three practical tips to make this week easier. It's educational, not medical advice — for anything specific to your pregnancy, please talk to your obstetrician. If you'd like a private, on-device way to log kicks, symptoms and appointments as they happen, Vyve is our private AI pregnancy tracker.

Your baby this week

At 27 weeks pregnant, your baby is roughly the size of a head of cauliflower — about 14.5 inches (37 cm) from head to heel and around 2 pounds (900 g). They've crossed a symbolic threshold this week: their measurements are firmly on the newborn scale rather than the fetal one.

The headlines for week 27 are inside the skull. Brain activity is ramping up sharply. Distinct sleep and wake patterns are becoming measurable — periods that look like REM sleep alternating with quieter stages. Whether your baby is technically "dreaming" is one of those open, gorgeous questions in developmental science, but the neural machinery for it is undeniably lighting up.

Other quiet but important things this week:

• Eyes fully open (most days). After starting to open around week 26, eyelids now open and close regularly. Your baby can respond to bright light, and eyelash development is finishing.
• Lungs practicing. Surfactant production continues, and rhythmic "breathing" movements — drawing amniotic fluid in and out — are more regular. Lungs won't be fully mature for many more weeks, but the practice matters.
• Hearing sharpens further. Your voice is now one of the clearest sounds in their world. Many parents notice their baby reacts to a specific song, a partner's laugh, or a favorite show's theme.
• Kicks with rhythm. You've likely noticed active and quiet stretches. Some parents feel little hiccups — small, regular pulses that go on for a few minutes and are entirely normal.
• Weight gain accelerates. Your baby is packing on more fat under the skin. Skin is becoming less translucent, less wrinkled and steadily more newborn-like.
• Taste buds. Yes, really — your baby can taste flavors that pass into the amniotic fluid from what you eat. Early food memories, arguably, start now.

Mom's body & symptoms

Your uterus is now well above your belly button, and the physical work of pregnancy is more noticeable day to day. Common week-27 symptoms include:

• Leg cramps — especially at night. The classic mid-calf clench that yanks you awake. Gentle calf stretches before bed, staying well hydrated and regular movement during the day usually help. Severe, persistent cramps or one-sided leg pain with swelling or redness needs your doctor's attention (to rule out clots).
• Backache and pelvic pressure. Ligaments continue to loosen, and the extra weight is pulling forward on your back and pelvis. Prenatal yoga, a maternity belt, a warm bath and side-sleeping with a pillow between the knees all help.
• Restless, broken sleep. Between more bathroom trips, restless legs, vivid dreams and a bigger bump, deep sleep is harder to hold. Naps stop being optional.
• Braxton Hicks contractions. Irregular, painless tightenings that come and go. Normal. Regular, painful contractions with lower back pain, bleeding or fluid loss are not — call your provider immediately.
• Heartburn and indigestion. Progesterone and less abdominal real estate combine forces. Smaller, more frequent meals and not lying down right after eating help.
• Swelling in feet and ankles. A little end-of-day puffiness is normal. Sudden or severe swelling — especially in hands and face, or paired with headaches or visual changes — is not, and warrants an urgent call to rule out preeclampsia.
• Stronger, more predictable movements. Your baby's kicks are unmistakable now. Get used to their active hours — you'll formalize kick counting in a week or two.
• Emotional shifts. The end-of-second-trimester milestone can bring up big feelings — excitement, nerves, tenderness, sudden overwhelm. All normal, all worth naming.

Anything sudden, severe or new — heavy bleeding, gushing fluid, sharp abdominal pain, a marked drop in fetal movement, severe headache with vision changes, or fever — is a call-your-doctor moment, not a wait-and-see one.

Nutrition tips for week 27

Your baby's demands on iron, calcium, protein and healthy fats are climbing as they lay down more fat and grow more brain tissue. The framework at week 27 is basically the same as week 26 — but with a slightly heavier lean into iron and calm blood sugar, because the third trimester's metabolic load is just around the corner.

• Iron. Your blood volume is still expanding and anemia risk rises. Lean red meat, eggs, lentils, beans, tofu, fortified cereals and dark leafy greens all help. Pair plant iron with vitamin C for better absorption. Take supplements only as advised.
• Calcium and vitamin D. Your baby is drawing on your calcium for their fast-growing bones. Dairy, fortified plant milks, tofu set with calcium, and greens — with vitamin D as commonly supplemented in pregnancy.
• Protein at every meal. Eggs, dairy, legumes, fish, poultry. Consistent protein supports baby's growth and your energy.
• Omega-3s (DHA). Your baby's brain is in a real growth phase. Low-mercury fish like salmon and sardines twice a week; algae-based DHA if you don't eat fish.
• Steady blood sugar. If your glucose screening came back borderline or higher, you may be working with a dietitian or your provider on a plan. Broadly, whole rather than refined carbs, protein with each meal, and not skipping meals help keep energy — and blood sugar — level.
• Fiber and fluids. Constipation and hemorrhoids are common now; plenty of vegetables, fruits, whole grains and water genuinely help.
• Small, frequent meals. Five or six modest meals often sit better than three big ones as your stomach loses room.

Still-avoid list: alcohol, raw or undercooked meats and eggs, unpasteurized dairy, high-mercury fish (shark, swordfish, king mackerel, tilefish), and excess caffeine (most guidance caps it at around 200 mg per day). Personalize any of this with your obstetrician or a prenatal dietitian.

Safe exercise this week

For an uncomplicated pregnancy, gentle regular movement remains one of the best investments you can make in this final second-trimester week — better sleep, less back pain, calmer blood sugar, better mood, easier labour recovery. Broadly supported at week 27:

• Walking — daily, low-impact, easy to scale. A 20-minute after-dinner walk also helps digestion and blood sugar.
• Swimming and water aerobics — the water takes weight off your spine, hips and pelvis. Many say this is the most comfortable they feel all week.
• Prenatal yoga — hip openers, side-lying poses, breathwork. Skip deep twists and lying flat on your back for long.
• Stationary cycling — low-impact, low fall risk, easy to control effort.
• Light strength training — bodyweight work and light weights to keep you carrying the bump well. Avoid breath holding and heavy lifts.
• Pelvic floor work. Both gentle Kegels and — critically — learning to release the pelvic floor. Consider a session with a pelvic health physiotherapist if available.
• Stretching. Calf stretches before bed for cramps, hip openers for pelvic pressure, thoracic openers for the between-shoulder-blade ache many people get now.

Skip or modify: contact sports, activities with fall risk (skiing, horse riding, mountain biking), hot yoga, scuba diving, and long stretches lying flat on your back. Stop and call your provider for any bleeding, leaking fluid, severe shortness of breath, chest pain, sudden swelling, or headache during exercise. When in doubt, especially with any pregnancy complication, check with your obstetrician.

Questions to ask your doctor

Week 27 is often a "get organized for the third trimester" visit if it lines up with one — or a good week to prepare the list for your next appointment. Consider asking:

• What are the results of my glucose screening? If you were screened at 24–26 weeks, this is the week to confirm and, if needed, follow up.
• When do we start biweekly visits? Most providers shift from monthly to every-two-weeks around week 28, then weekly at 36. Confirm the cadence.
• Am I Rh-negative? Do I need the Rh immunoglobulin injection? If your blood type is Rh-negative, most protocols recommend an injection around week 28.
• How is my iron? Anemia is common late second/early third trimester — ask about testing and any supplement plan.
• How is my blood pressure trending? The third trimester is when preeclampsia risk rises; trend-watching starts to matter more.
• When should I formally start kick counts? Usually around week 28 — confirm timing and technique.
• Which childbirth class and hospital tour should I book? A good week to line these up if you haven't.
• Any travel restrictions? Many airlines restrict flying after week 28 or 32; check now if you have plans.
• What signs of preterm labor should I watch for? Regular contractions, lower back pain, fluid changes, and pelvic pressure patterns.

3 practical tips for week 27

1. Book the childbirth class and hospital tour. They fill up. Whether you want a full multi-week class, a weekend intensive, or an online option, get it on the calendar this week so it doesn't slide.
2. Stretch your calves before bed — every night. Sixty seconds each side, gently, standing or against a wall. It's the single most consistently helpful thing for the nighttime leg cramps that peak right about now.
3. Write down your third-trimester questions as they come. The best time to remember a question is the moment you have it, not five minutes before your next appointment. A note in your phone, or a running list in a private tracker, keeps them somewhere useful.

How Vyve helps you track pregnancy — privately

Everything you're tracking now — kick counts, symptoms, blood pressure, iron, glucose results, birth plan drafts, questions for your obstetrician — is deeply personal data. It shouldn't be sitting on ad-tech infrastructure or feeding some third-party model. That's the whole reason we built Vyve the way we did.

Vyve is a private, AI-powered pregnancy tracker that runs on your device. It helps you log week-by-week milestones, count kicks with a gentle timer, capture symptoms as they happen, keep a running record of appointments and questions, and generate a clean summary for every visit. Everything stays encrypted on your phone. There is no required account, and nothing about your body or your baby is sold or shared.

For week 27 specifically, that means one place to note your glucose result and follow-up, your Rh status, the childbirth class you booked, when your biweekly visits start, and the exact wording your obstetrician used about your birth plan. Small notes now are a real record when you need it.

Frequently asked questions

How big is my baby at 27 weeks pregnant?

At 27 weeks, your baby is about the size of a head of cauliflower — roughly 14.5 inches (about 37 cm) from head to heel and weighing around 2 pounds (about 900 grams). This week they cross a symbolic threshold: their weight and length are firmly on the newborn scale rather than the fetal one.

Is week 27 the last week of the second trimester?

Yes. Week 27 is the final week of your second trimester. The third trimester begins at week 28. It's a natural moment to look back at how far you've come and to line up your third-trimester plans — closer appointments, birth classes, hospital tour, and finalizing your birth preferences with your obstetrician.

Why do I get leg cramps at 27 weeks pregnant?

Leg cramps — especially at night — are common in the second half of pregnancy. The exact cause isn't fully understood, but contributing factors likely include the extra weight your legs are carrying, changes in circulation, pressure on nerves from your growing uterus, and shifts in electrolytes and hydration. Gentle calf stretches before bed, staying well hydrated and moving regularly through the day usually help. Mention them to your doctor if they're severe, persistent, or paired with swelling or redness in one leg.

Does my baby dream at 27 weeks?

Sort of. Around week 27, your baby has clear sleep and wake cycles, and researchers detect brain activity consistent with REM-like sleep, which is the stage of sleep in which adults dream. Whether that qualifies as "dreaming" in the way we experience it is a beautiful open question — but the brain infrastructure for it is genuinely lighting up now.

Is exercise still safe at 27 weeks pregnant?

For most uncomplicated pregnancies, yes. Walking, swimming, prenatal yoga, stationary cycling and gentle strength work are broadly supported at 27 weeks. Skip anything with fall risk, contact, hot yoga, or long stretches lying flat on your back. Listen to your body — you may need to scale intensity down as your bump grows — and check with your obstetrician about anything specific to your pregnancy.

Disclaimer: Educational, not medical advice. Consult your obstetrician for anything specific to you and your pregnancy.