27 Weeks Pregnant
At 27 weeks pregnant your baby is about 14.5 inches long and close to 2 pounds — roughly the size of a head of cauliflower — and very active, kicking, stretching, rolling, and practicing breathing-like movements. This is the last week of the second trimester. The brain is in a stretch of remarkable growth, and the Tdap vaccine window opens this week.
Your week at a glance
| This week | Details |
|---|---|
| Baby size | About a head of cauliflower, roughly 14.5 in and close to 2 lb (about 875 g) |
| What is developing | Brain folds, sleep and wake cycles, hiccups, breathing rehearsal, open eyes |
| Your symptoms | Swollen ankles, back pain, Braxton Hicks, colostrum, varicose veins, dizziness |
| To-do | Plan your Tdap, elevate your feet, keep up Kegels, pack a starter hospital bag |
How big is your baby at 27 weeks?
This is the last week of the second trimester. Your baby is about 14.5 inches long and close to 2 pounds, roughly the size of a head of cauliflower. They are very active right now — kicking, stretching, rolling, and even practicing breathing-like movements by drawing amniotic fluid in and out of their lungs. You may also feel little rhythmic flutters that are actually hiccups, which babies have several times a day at this stage. None of it hurts them; the rhythmic jumps are simply their diaphragm getting in some rehearsal time before the real thing.
The brain is in a stretch of remarkable growth, with the surface starting to develop the folds and grooves that mark a mature brain. Networks of neurons are forming connections that will support memory, learning, and the senses. Your baby can hear well now and may startle, calm down, or move more when familiar voices, music, or sounds come through. Their eyes are open during awake periods and closed when they sleep, and they can detect strong light through your belly. Babies at this point have clear sleep and wake cycles, including REM sleep, even though their days and nights may not match yours yet.
A loose habit of noticing your baby's movement patterns is a gentle way to feel connected this week. You do not need to formally count yet — many providers begin recommending dedicated kick counts at 28 weeks — but tuning in to your baby's typical busy and quiet times now makes any future changes much easier to spot later. Talking, reading aloud, or playing music to your bump can be especially sweet right now because your baby genuinely hears and reacts to you. If you ever notice a real drop-off from your baby's normal pattern, lie down on your left side, have a snack and a cold drink, and call your provider if movement does not pick up.
27 weeks pregnant symptoms
The top of your uterus, called the fundus, now sits about 2 to 3 inches above your belly button, with a fundal height of around 27 centimeters. Your blood volume is close to its peak, which shapes a lot of how you feel this week:
- Feeling warmer than usual and looking a little flushed, with hands and feet that swell by the end of the day
- A lower back that aches by evening, from the extra weight, the forward pull of your belly, and looser pelvic joints
- Hemorrhoids and varicose veins from the pressure of the uterus on your lower-body veins
- Braxton Hicks contractions — short, painless squeezes that come and go, often after you have been on your feet, are dehydrated, or your baby is active
- Colostrum (a thick, yellowish first milk) leaking from your breasts
- More vivid dreams and occasional dizziness when you stand up too fast
- Mild leg cramps at night and a belly button that may pop out
True labor contractions, in contrast to Braxton Hicks, get longer, stronger, and closer together rather than fading when you change positions. Emotionally, this is the gentle on-ramp to the third trimester — a flicker of nesting energy alongside a quiet flicker of anxiety about labor and parenting. If anxious thoughts feel persistent or are getting in the way of sleeping or enjoying things you love, please tell your provider. Mental health screening is a standard part of prenatal care, and support is readily available without judgment.
Taking care of yourself this week
A few small adjustments can take real weight off swollen feet, sore hips, and an achy back. Whenever you sit, prop your feet up on a stool, ottoman, or low box — it only takes a few inches of elevation to help fluid drain back. Avoid standing motionless for long stretches; shift weight, walk a few steps, or do gentle calf pumps. Keep your pelvic-floor muscles strong with daily Kegels (squeeze as if stopping urine flow, hold a few seconds, release; repeat about 10 times, two or three times a day). Side-sleep with a pillow between your knees, and try a warm bath or heating pad on your low back when it really protests.
- Lean into fiber and water — whole grains, beans, fruit, and vegetables, plus about 80 to 100 ounces of fluids a day — to manage constipation and hemorrhoids.
- Keep washing all fresh produce thoroughly under running water; Toxoplasma can hide on unwashed greens, berries, and herbs.
- Keep avoiding raw or undercooked meat, unpasteurized soft cheeses, and high-mercury fish like swordfish and king mackerel; low-mercury options like salmon, sardines, and trout are great omega-3 picks.
- Pack a starter hospital bag — comfortable clothes, warm socks, toiletries, a phone charger, a going-home outfit for your baby, and a copy of your prenatal records — and keep it easy to grab.
- Keep up the preparation — interview a couple of pediatricians, and sign up for a childbirth class, hospital tour, or breastfeeding class if your hospital offers them.
Doing one small task per week between now and 36 weeks keeps the to-do list manageable instead of overwhelming.
Appointments & tests
The Tdap vaccine window officially opens this week. Tdap protects against tetanus, diphtheria, and pertussis (whooping cough). The CDC and ACOG recommend it during every pregnancy, ideally between weeks 27 and 36, because antibodies your body makes after the shot cross the placenta and give your newborn early protection against whooping cough — a disease that can be especially dangerous for the youngest babies, before they are old enough for their own vaccines. The shot is a simple injection in your upper arm, and a sore arm for a day or two is the most common side effect.
A routine visit around now usually includes a blood pressure check, a urine dip looking for protein and sugar, a weight check, a fundal-height measurement, and listening to your baby's heartbeat with a Doppler. Your provider will ask about your baby's movement patterns, any swelling, headaches, or vision changes, your sleep and mood, and any new symptoms. If your gestational diabetes screen showed an elevated value, you may have already done or be scheduled for the longer three-hour glucose tolerance test. If you are Rh-negative, expect to confirm that RhoGAM is scheduled for around week 28.
This is a good visit to bring questions to. You might ask: "When should I get my Tdap, and is it covered by my insurance?" "Do you also recommend an RSV vaccine for me, and if so when?" "Starting when should I count kicks, and how do you want me to track them?" "What signs of preterm labor should I watch for?" "When do my appointments switch to every two weeks?" If you have a partner or support person who plans to be at the birth, this is a great time for them to start coming to appointments.
Call your provider if
- Sudden, severe swelling of the face or hands, a persistent headache that does not ease with rest and water, blurry vision, or seeing spots and flashes (possible preeclampsia)
- Sudden severe upper-belly pain just under your right ribs, or rapid weight gain over a few days
- Any vaginal bleeding, including spotting, or a gush or steady trickle of fluid that could be amniotic fluid
- Regular, painful contractions before 37 weeks (especially four or more in an hour, or tightening that is getting longer, stronger, and closer together)
- A clear, lasting drop in your baby's movement, burning with urination, a fever above 100.4°F, severe one-sided abdominal pain, or sudden swelling, redness, warmth, or pain in one leg
Reflects Mayo Clinic and Cleveland Clinic second-trimester fetal-development references, Cleveland Clinic kick-count guidance, and Mayo Clinic fundal-height guidance, 2024–2026.
Related questions
- How big is the baby at 27 weeks pregnant?
- About 14.5 inches long and close to 2 pounds, roughly the size of a head of cauliflower. This is the last week of the second trimester, and your baby is very active — kicking, stretching, rolling, and practicing breathing-like movements.
- When can I get the Tdap vaccine in pregnancy?
- The Tdap vaccine window officially opens this week. The CDC and ACOG recommend it during every pregnancy, ideally between weeks 27 and 36, because antibodies your body makes after the shot cross the placenta and give your newborn early protection against whooping cough before they are old enough for their own vaccines.
- When should I start counting kicks?
- Many providers begin recommending dedicated kick counts around 28 weeks. You do not need to formally count yet at 27 weeks, but tuning in to your baby's typical busy and quiet times now makes any future changes much easier to spot later. If movement drops off, lie on your left side, have a snack and a cold drink, and call your provider if it does not pick up.
- What are the warning signs of preeclampsia at 27 weeks?
- Sudden, severe swelling of the face or hands, a persistent headache that does not ease with rest and water, blurry vision or seeing spots and flashes, sudden severe upper-belly pain just under your right ribs, or rapid weight gain over a few days can all be early warnings and deserve a same-day call to your provider.
Sources & further reading
ParentFlow: one free app, pregnancy to age six
ParentFlow follows your pregnancy week by week — baby size, what's developing, your symptoms, and the appointments and warning signs that matter — then becomes a free baby tracker for feeds, sleep, and growth after birth. Free on iPhone and Android.
App Store Google Play Open Web AppThis article reflects current ACOG, Mayo Clinic, Cleveland Clinic, CDC, and FDA guidance and is for educational purposes only. It does not constitute medical advice. ParentFlow is a wellness companion — not a substitute for your obstetric provider. For any medical concern, contact your healthcare provider.