20 weeks pregnant
Halfway there! Your baby weighs about 300 grams and is 25 cm from head to heel.
Week 20 is the exact halfway point of pregnancy. Your baby is about 25 cm from head to heel, and movements can now be felt regularly.
This week’s ultrasound image
Expected ultrasound appearance and measurements at week 20 (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)
25.6 cm
Head diameter
48 mm
Head circumference
178 mm
Femur length
33 mm
Estimated weight
300 g
Heart rate
145 bpm
How big is your baby this week?
About the size of a banana
What can be seen on the ultrasound?
BPD is about 48 mm, HC about 178 mm, AC about 155 mm and FL about 33 mm. The estimated weight is around 300 grams. This is one of the most popular weeks for the anomaly scan.
Your baby’s development
Your baby is about the length of a banana. Hair and eyebrows appear, and your baby swallows amniotic fluid. The first stool (meconium) begins to form in the bowel.
Changes in your body
The top of your womb reaches the level of your belly button. You may feel your baby’s kicks, and your belly button may start to flatten.
Check-ups at this stage
- Anomaly scan
- Routine check: blood pressure, weight, urine
- Planning the glucose tolerance test and blood count for weeks 24–28
Tips for this week
- Try to notice your baby’s movements every day
- Discuss any travel plans with your doctor
- Start looking into antenatal classes
When should you see your doctor?
Contact your doctor if you have bleeding, regular contractions, leaking fluid, a severe headache, blurred vision 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
How much should the baby weigh at 20 weeks?
On average, around 300 grams. Remember that the estimated weight on ultrasound can vary by up to 15 per cent.
How often should I feel my baby kick?
Movements may be irregular at this stage. After week 28, your doctor may recommend counting movements daily.
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