How many months is 27 weeks pregnant?

27 weeks pregnant puts you in month 6 of pregnancy. Week 27 is the last week of that month, and month 7 starts at week 28. Providers count in weeks; months are approximate.

How big is the baby at 27 weeks?

At 27 weeks, the baby is about the size of a cauliflower, roughly 36.6 cm long and around 875 g. That is an average; healthy babies vary.

What happens if a baby is born at 27 weeks?

Most babies born at 27 weeks survive. US data from 19 university hospitals show that 90.3% of babies born alive at 27 weeks survived to go home, rising to 94.0% at 28 weeks. A baby born this early is cared for in a neonatal unit, which helps with breathing, feeding, warmth and fighting infection. Steroid injections before birth can help the lungs mature. Magnesium sulphate, given through a drip to mothers in labour between 24 and 29 weeks, can help protect the baby's brain.

Is the baby fully developed at 27 weeks?

Not yet. The organs are all in place, but several are still maturing. The lungs could work with medical help, and they now make surfactant, a substance the baby will need to breathe air. The brain is growing fast, and the nervous system can already control some body functions. Over the next few weeks, the baby will also gain a lot of fat. The lungs and brain are the last to mature, so every extra week in the womb helps.

What position is the baby in at 27 weeks?

Often not head-down yet, and that's normal. In a US study of 4,024 pregnancies scanned from 28 weeks on, about 1 in 4 babies (24.4%) were bottom-first at 28 weeks. By 37 weeks, only 3.7% still were. Most babies turn by themselves. If your baby is bottom-first at about 36 weeks, you'll usually be offered an ECV, where a doctor tries to turn the baby by pressing on your belly. Your midwife or doctor will check the position at later visits.

Is cramping normal at 27 weeks pregnant?

Some tightening and aching is common. Braxton Hicks contractions feel like your bump hardening or like mild period pain. They're irregular, they stay mild, and they usually fade when you walk or shift position. Before 37 weeks, regular tightenings are different. US guidance says to call if you have more than six in an hour. Also call your provider or maternity unit about period-type pains that keep coming, backache that's not usual for you, pressure in your pelvis, or a gush or trickle of fluid.

Is nausea normal at 27 weeks pregnant?

For most people, morning sickness has gone by 16 to 20 weeks, so feeling sick at 27 weeks often has another cause. Indigestion is a common one. The growing baby presses on your stomach, which can leave you feeling sick, full or bloated after meals. Small, frequent meals and no food in the 3 hours before bed can help. Some signs need a call to your maternity unit or provider straight away: vomiting, feeling very unwell, or heartburn that medicine doesn't ease. So do a bad headache, vision problems or sudden swelling. All of these can point to pre-eclampsia.

27 Weeks Pregnant

At 27 weeks pregnant, you've reached the last week of the second trimester and are about two-thirds of the way through. Your baby now measures about 36.6 cm from head to heel, close to the size of a head of cauliflower, and is getting plumper as fat fills out the folds of skin. The eyes can now open and blink, and eyelashes have grown. For you, bloating, constipation and snoring are common. In the US, this is also the week the Tdap vaccine window opens. This page covers the checks and vaccines ahead, sleep position, which way the baby is lying, and what happens if a baby is born now.

What trimester is 27 weeks?

Week 27 is in the second trimester, which runs from week 13 to week 27 (NHS). It is week 15 of 15 in this trimester, and the third trimester starts at week 28.

Week 27 — second trimester, month 6; 13 weeks to go until your due date.
Baby's size — about a cauliflower, ~36.6 cm.

Not sure it's 27 weeks? Try our due date calculator.

★ Last week of the second trimester.

How big is your baby at 27 weeks?

Size of a

cauliflower

Length, head to heel

~36.6 cm

Weight

~875 g

Up from a lettuce last week to a cauliflower now.

Baby development at week 27

The last week of the second trimester. The fetus now has sleep and wake cycles, can hear sounds from outside the womb, and the brain is very active. The lungs are still immature but capable of functioning with help if birth came early. About the size of a large cauliflower.

What an ultrasound shows at 27 weeks

Most people don't have a scan at 27 weeks. You might have one to check growth, or because you're expecting twins. If you do, the baby may look rounder than a few weeks ago, with less wrinkled skin, and it can now open and close its eyes.

Vaccines come up around now. In the US, the Tdap vaccine protects your baby against whooping cough. It is recommended in each pregnancy between weeks 27 and 36, preferably near the start of that range. The US RSV vaccine for pregnancy (Abrysvo) comes later, at 32 to 36 weeks. In most of the country it is given only from September to January. UK timings differ: whooping cough protection can start as early as 16 weeks, and the RSV jab is offered from 28 weeks.

In the UK, your next checkup is at 28 weeks. It usually includes a blood test to check your iron levels and blood group. If your blood type is Rh negative (also called D negative) and your baby may be Rh positive, you may be offered an injection to protect the baby from rhesus disease. Wherever you live, if you haven't had your diabetes screening yet, it's due by 28 weeks.

Your body at 27 weeks

Regular movement patterns you may start to recognise
Leg cramps and restless legs
Shortness of breath
Braxton Hicks contractions

Your belly at 27 weeks

At 27 weeks, most bumps measure 25 to 29 cm from the pubic bone to the fundus. The fundus keeps rising and reaches your breastbone at around 36 weeks. The baby now squeezes your stomach, and the hormone progesterone slows your gut. So bloating and constipation are common. Drink plenty of water, and choose high-fibre foods such as wholemeal bread and pasta. Lots of fruit and vegetables help too.

You may also snore more, because the inside of your nose can swell in pregnancy. From next week, you'll be advised to settle down to sleep on your side, and either side is fine. Research suggests that back-sleeping from this stage can double the risk of stillbirth. A pillow under your bump and another between your bent knees can make side-sleeping easier. If you wake up on your back, don't worry: just turn onto your side again.

Tips for week 27

Start noting your baby's active and quiet times
Calf stretches, rubbing the muscle and pulling your toes up can ease leg cramps
Begin thinking about antenatal classes

27 Weeks Pregnant: your questions

What trimester is 27 weeks?: Week 27 is in the second trimester, which runs from week 13 to week 27 (NHS). It is week 15 of 15 in this trimester, and the third trimester starts at week 28.
How many months is 27 weeks pregnant?: 27 weeks pregnant puts you in month 6 of pregnancy. Week 27 is the last week of that month, and month 7 starts at week 28. Providers count in weeks; months are approximate.
How big is the baby at 27 weeks?: At 27 weeks, the baby is about the size of a cauliflower, roughly 36.6 cm long and around 875 g. That is an average; healthy babies vary.
What happens if a baby is born at 27 weeks?: Most babies born at 27 weeks survive. US data from 19 university hospitals show that 90.3% of babies born alive at 27 weeks survived to go home, rising to 94.0% at 28 weeks. A baby born this early is cared for in a neonatal unit, which helps with breathing, feeding, warmth and fighting infection. Steroid injections before birth can help the lungs mature. Magnesium sulphate, given through a drip to mothers in labour between 24 and 29 weeks, can help protect the baby's brain.
Is the baby fully developed at 27 weeks?: Not yet. The organs are all in place, but several are still maturing. The lungs could work with medical help, and they now make surfactant, a substance the baby will need to breathe air. The brain is growing fast, and the nervous system can already control some body functions. Over the next few weeks, the baby will also gain a lot of fat. The lungs and brain are the last to mature, so every extra week in the womb helps.
What position is the baby in at 27 weeks?: Often not head-down yet, and that's normal. In a US study of 4,024 pregnancies scanned from 28 weeks on, about 1 in 4 babies (24.4%) were bottom-first at 28 weeks. By 37 weeks, only 3.7% still were. Most babies turn by themselves. If your baby is bottom-first at about 36 weeks, you'll usually be offered an ECV, where a doctor tries to turn the baby by pressing on your belly. Your midwife or doctor will check the position at later visits.
Is cramping normal at 27 weeks pregnant?: Some tightening and aching is common. Braxton Hicks contractions feel like your bump hardening or like mild period pain. They're irregular, they stay mild, and they usually fade when you walk or shift position. Before 37 weeks, regular tightenings are different. US guidance says to call if you have more than six in an hour. Also call your provider or maternity unit about period-type pains that keep coming, backache that's not usual for you, pressure in your pelvis, or a gush or trickle of fluid.
Is nausea normal at 27 weeks pregnant?: For most people, morning sickness has gone by 16 to 20 weeks, so feeling sick at 27 weeks often has another cause. Indigestion is a common one. The growing baby presses on your stomach, which can leave you feeling sick, full or bloated after meals. Small, frequent meals and no food in the 3 hours before bed can help. Some signs need a call to your maternity unit or provider straight away: vomiting, feeling very unwell, or heartburn that medicine doesn't ease. So do a bad headache, vision problems or sudden swelling. All of these can point to pre-eclampsia.

Useful at week 27

Fetal viability — how the odds change from 22 to 28 weeks
Flying while pregnant — after 28 weeks, airlines may ask for a letter
Is Pepcid safe in pregnancy? — if heartburn keeps you up at night
Pregnancy weight gain calculator — check your gain as the third trimester starts
Pregnancy weeks to months — 27 weeks is the last week of month 6

← All weeks: the full pregnancy week-by-week guide

Sources

Checked against the following public guidance on October 2, 2026. Advice can differ between countries; your doctor, nurse or midwife can apply it to you.