# 27 Weeks Pregnant: Baby Size, Symptoms & What to Expect | Clever Mum

> 27 weeks pregnant — your baby is the size of a cauliflower. What's developing, what you might feel, and what to focus on this week.

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Third trimester

 
#  27 weeks pregnant

 

Your baby is about the size of a cauliflower 

   [ CP ](/authors/parenting-desk/)  
 By [ Clever Mum Parenting ](/authors/parenting-desk/) · Parenting guides 

 
 Published 11 July 2026  

      
 
Quick answer — What happens at 27 weeks pregnant? 

 
At 27 weeks pregnant, your baby is about the size of a cauliflower, roughly 36.6cm and around 875g. Welcome to the third trimester.

    
Who should skip this

 
Skip this page if you need personal medical advice — it is general NHS-aligned information, not a substitute for your midwife. If your baby's movements slow or change, call your maternity unit, not a website.

    
## How big is the baby at 27 weeks pregnant?

 
At 27 weeks pregnant, your baby is about the size of a cauliflower, roughly 36.6cm and around 875g. Welcome to the third trimester. The baby now sleeps and wakes at regular intervals and may hiccup (you'll feel rhythmic little jolts). Their lungs and brain are developing fast. These are typical averages — your midwife's measurements are the ones that matter for your pregnancy.

 
## What might you feel at 27 weeks?

 
Most people at 27 weeks notice some mix of the symptoms below — and plenty notice none of them. The final stretch begins. Tiredness can return, along with heartburn, swelling and trouble sleeping. You may notice colostrum (early milk) leaking from your breasts. None of this is a diagnosis; contact your midwife if something worries you.

  
### Common symptoms this week

 
 * Returning tiredness
* Heartburn
* Baby hiccups (rhythmic jolts)
* Colostrum leaks for some
 
 

Symptom lists are typical, never exhaustive — and having none of them is normal too.

  
## What should you do at 27 weeks pregnant?

 
The useful job this week is practical, not medical. From 28 weeks you'll have more frequent antenatal appointments. Keep counting movements and report any change without delay. Pair it with the NHS week-by-week guide if you want a second description of the same stage.

    
### Week 27 checklist

 
 * Note the third-trimester appointment schedule — visits get more frequent from 28 weeks
* Keep up movement awareness — pattern changes always warrant a call
 
   
## What else is useful at 27 weeks?

 

Use the week page for size and symptoms; use the guides below for the decisions that
                actually sit in this window — pay, packing, car seats, labour signs.

 
 *  [Due date calculator](/tools/due-date-calculator/) 
*  [Trimester to-do list](/pregnancy/pregnancy-to-do-list-by-trimester/) 
*  [Maternity leave and pay](/pregnancy/maternity-leave-and-pay-uk/) 
*  [Best infant car seats](/best/best-car-seats-uk/) 
 
    
## 27 weeks pregnant: common questions

    When does the third trimester start?   
 At week 27–28 (definitions vary slightly; the NHS uses week 27). It runs to the birth, brings more frequent antenatal appointments, and is when tiredness often returns alongside heartburn and disturbed sleep as the baby takes up more room. 

   How big is my baby at 27 weeks pregnant?   
 At 27 weeks, your baby is approximately the size of a cauliflower, about 36.6cm and around 875g. These are approximate averages — every baby grows at its own pace. 

   What's happening at 27 weeks pregnant?   
 Welcome to the third trimester. The baby now sleeps and wakes at regular intervals and may hiccup (you'll feel rhythmic little jolts). Their lungs and brain are developing fast. For you: the final stretch begins. tiredness can return, along with heartburn, swelling and trouble sleeping. you may notice colostrum (early milk) leaking from your breasts. 

   Which trimester is 27 weeks?   
 27 weeks pregnant is in the third trimester. The first trimester runs to the end of week 12, the second from weeks 13 to 26, and the third from week 27 to birth. 

     
## 
Sources & further reading

 
 *  [ You and your baby at 4 to 40 weeks pregnant ](https://www.nhs.uk/pregnancy/week-by-week/)  — NHS 
*  [ Your baby's movements ](https://www.nhs.uk/pregnancy/keeping-well/your-babys-movements/)  — NHS 
 
   [← 26 weeks](/pregnancy/week/26/) [All weeks](/pregnancy/week/) [28 weeks →](/pregnancy/week/28/)  

This is general information, not medical advice — every pregnancy is different. For
          anything that worries you, and for all your antenatal care, speak to your midwife or GP.
          If your baby's movements ever slow down or change, contact your maternity unit
          immediately, day or night. Reviewed August 2026.

    
## Week 27 at a glance

   Trimester Third trimester  Baby size cauliflower  Approx length ~36.6cm  Approx weight ~875g  Weeks to go 13 (to 40)     
Work out your dates

 

Not sure how many weeks you are? Our
[due date calculator](/tools/due-date-calculator/)
maps your weeks and trimester dates from your last period.