27 weeks pregnant
The last week of the second trimester; your baby is about 36 cm and 875 grams.
Week 27 is the last week of the second trimester. Your baby’s brain is developing rapidly, and you may feel rhythmic hiccups.
This week’s ultrasound image
Expected ultrasound appearance and measurements at week 27 (illustrative, to-scale drawing).
Abbreviations on the screen
- GS
- Gestational sac diameter
- YS
- Yolk sac
- CRL
- Crown–rump length
- NT
- Nuchal translucency
- BPD
- Biparietal diameter (head width)
- HC
- Head circumference
- AC
- Abdominal circumference
- FL
- Femur (thigh bone) length
- EFW
- Estimated fetal weight
- FHR
- Fetal heart rate (beats per minute)
- GA
- Gestational age (weeks + days)
- UA PI
- Umbilical artery Doppler resistance (PI)
Length (head to heel)
35.6 cm
Head diameter
69 mm
Head circumference
253 mm
Femur length
51 mm
Estimated weight
875 g
Heart rate
140 bpm
How big is your baby this week?
About the size of a cabbage
What can be seen on the ultrasound?
BPD is about 69 mm, HC about 253 mm, AC about 232 mm and FL about 51 mm. The estimated weight is around 875 grams.
Your baby’s development
Your baby is about the size of a cabbage. Brain tissue is increasing rapidly. Hiccups can be felt as rhythmic twitches in your tummy.
Changes in your body
Tiredness may increase again. Leg cramps, back pain and heartburn are common.
Check-ups at this stage
- Planning the anti-D injection at week 28 if you are Rh negative
- Whooping cough (Tdap) vaccine
- Routine check: blood pressure, weight, urine
Tips for this week
- Keep paying attention to your baby’s movements every day
- Lying on your left side supports circulation
- Talk to your doctor about where you will give birth and what to expect
When should you see your doctor?
Contact your doctor if you have regular contractions, bleeding, fluid leaking from the vagina, a severe headache or reduced baby movements.
Growth by week
Values are averages; differences of a few days or a few millimetres between babies are normal.
| Pregnancy weeks | Crown–rump length (cm) | Weight (g) |
|---|---|---|
| Week 4 | — | — |
| Week 5 | — | — |
| Week 6 | 4 mm | — |
| Week 7 | 10 mm | — |
| Week 8 | 16 mm | 1 g |
| Week 9 | 23 mm | 2 g |
| Week 10 | 32 mm | 4 g |
| Week 11 | 43 mm | 8 g |
| Week 12 | 55 mm | 14 g |
| Week 13 | 68 mm | 23 g |
| Week 14 | 85 mm | 43 g |
| Week 15 | 100 mm | 70 g |
| Week 16 | 115 mm | 100 g |
| Week 17 | 128 mm | 140 g |
| Week 18 | 140 mm | 190 g |
| Week 19 | 152 mm | 240 g |
| Week 20 | 25.6 cm | 300 g |
| Week 21 | 26.7 cm | 360 g |
| Week 22 | 27.8 cm | 430 g |
| Week 23 | 28.9 cm | 501 g |
| Week 24 | 30 cm | 600 g |
| Week 25 | 31.9 cm | 660 g |
| Week 26 | 33.8 cm | 760 g |
| Week 27 | 35.6 cm | 875 g |
| Week 28 | 37.5 cm | 1005 g |
| Week 29 | 38.8 cm | 1153 g |
| Week 30 | 40 cm | 1319 g |
| Week 31 | 41.3 cm | 1502 g |
| Week 32 | 42.5 cm | 1702 g |
| Week 33 | 43.6 cm | 1918 g |
| Week 34 | 44.8 cm | 2146 g |
| Week 35 | 45.9 cm | 2383 g |
| Week 36 | 47 cm | 2622 g |
| Week 37 | 48 cm | 2859 g |
| Week 38 | 49 cm | 3083 g |
| Week 39 | 50 cm | 3288 g |
| Week 40 | 51 cm | 3462 g |
Frequently asked questions
Is it normal for the baby to have hiccups?
Yes. Short, rhythmic twitches felt in your tummy are usually your baby’s hiccups and show that the breathing muscles are developing.
Who needs the anti-D injection?
It is usually given at week 28, and after birth if needed, to mums-to-be who are Rh negative and do not have antibodies.
Your pregnancy care at SoftCare Clinic
Book an appointment with our specialist doctors for your ultrasound check-up and any questions you may have.
The information on this page is for general guidance only and does not replace a medical examination. Measurements are average values; please discuss your own results with your doctor.
Medical content editor: Op. Dr. Şükrü Sanus