30 weeks pregnant
Your baby is about 40 cm and 1.3 kg; the folds of the brain become more defined.
At week 30, the folds of your baby’s brain become more defined. A growth scan can be used to assess your baby’s development.
This week’s ultrasound image
Expected ultrasound appearance and measurements at week 30 (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)
40 cm
Head diameter
78 mm
Head circumference
282 mm
Femur length
58 mm
Estimated weight
1319 g
Heart rate
138 bpm
UA PI
0.95
How big is your baby this week?
About the size of a bunch of broccoli
What can be seen on the ultrasound?
BPD is about 78 mm, HC about 282 mm, AC about 264 mm and FL about 58 mm. Umbilical cord Doppler and the amniotic fluid can be assessed.
Your baby’s development
Your baby is about the size of a bunch of broccoli. The fine hair covering the body (lanugo) starts to thin out. The bone marrow is producing blood cells.
Changes in your body
Tiredness, sleeplessness, heartburn and lower back pain may increase. Mood changes are common.
Check-ups at this stage
- Growth scan and Doppler (weeks 30–32)
- Routine check: blood pressure, weight, urine
- Blood count
Tips for this week
- Take short rest breaks during the day
- Breathing exercises help you prepare for labour
- Start learning about breastfeeding
When should you see your doctor?
Contact your doctor if you have reduced baby movements, bleeding, leaking fluid, regular contractions, a severe headache or blurred vision.
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
Why is a growth scan done?
Your baby’s estimated weight is calculated from head, abdomen and thigh measurements; the scan checks whether growth matches the week, and assesses the amniotic fluid and placenta.
What does a ‘normal’ Doppler result mean?
If the resistance (PI) in the umbilical artery is within the expected range for the week, the placenta is considered to be nourishing your baby well.
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