What Does a Baby Look Like at 24 Weeks?

Learn what a baby may look like at 24 weeks on ultrasound, how facial contours change, what 3D ultrasound can show, and why every scan looks different.

At about 24 weeks, the fetal face is usually more recognizable than it was earlier in the second trimester. The forehead, nose, lips and chin can often be displayed on 3D surface rendering when the face is accessible to the ultrasound beam. The fetus is still relatively small, but facial contours are becoming easier to appreciate. Classic 3D ultrasound studies reported improved facial visualization at or after 24 weeks compared with earlier gestation. [9, 18]

Educational visual for what a baby may look like at 24 weeks on ultrasound. Educational illustration; not a diagnostic ultrasound image.
Visual overview of what a 24-week ultrasound can show. Educational illustration; not a diagnostic ultrasound image.

Learn what a baby may look like at 24 weeks on ultrasound, how facial contours change, what 3D ultrasound can show, and why every scan looks different.

What changes between 20 and 24 weeks?

Growth continues rapidly. The face gains size and definition, while the body continues developing muscle and beginning to accumulate more fat. MedlinePlus describes ongoing development of the lungs, blood-forming system and other organs during weeks 23 to 25. The visible difference on 3D ultrasound is therefore not simply a larger version of the 20-week face. Surface contours gradually become more apparent as tissue volume changes. [7]

Educational comparison of fetal facial change from 20 to 32 weeks, with 2D profile views and sepia 3D ultrasound surface renderings. Educational illustration; not a diagnostic ultrasound image.
Between 20 and 24 weeks the face typically gains size and definition. Educational illustration of 20–32 week change with 2D profiles and 3D surface renderings; not a diagnostic ultrasound image.

Why 24 weeks can be useful for facial imaging

At this stage there can be a useful combination of fetal size and available fluid around the face. Published work has reported particularly satisfactory recognizable 3D images beginning around 24 weeks. However, there is no guarantee that a 24-week scan will produce a clear facial rendering. Position can matter more than gestational age on a particular day. [8, 18]

What you may see

A favorable 3D view may show the forehead, eyelid region, nose, lips, cheeks and chin. Four-dimensional ultrasound can display sequential 3D volumes over time, allowing surface movements to be seen. Research at 20 to 24 weeks has documented observable movements such as mouthing and yawning, but an isolated rendered expression should not be interpreted as an emotional state. [16]

Why the face may still be hidden

A hand, forearm, placenta or uterine wall can sit directly in front of the face. A limited fluid interface may prevent the rendering algorithm from separating the facial surface cleanly from adjacent tissue. The fetus may also be facing the maternal spine. These are common imaging limitations, not evidence that something is wrong. [8, 20]

Educational diagram of geometry that can hide the fetal face. Educational illustration; not a diagnostic ultrasound image.
A hand, placenta, or uterine wall can sit in front of the face and hide the surface. Educational illustration; not a diagnostic ultrasound image.

From ultrasound volume to 3D representation

A 3D ultrasound acquisition stores a volume rather than a single flat frame. Software can render selected surfaces from that volume. When the source data are sufficiently complete, the same principle of spatial reconstruction can be used for educational visualization and, with appropriate processing, physical models. The accuracy of any downstream representation depends on the quality and completeness of the original volume.

Educational infographic comparing 2D, 3D and 4D ultrasound side by side. Educational illustration; not a diagnostic ultrasound image.
2D, 3D and 4D ultrasound: a side-by-side comparison. Educational illustration; not a diagnostic ultrasound image.

Medical disclaimer

This article is intended for educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional regarding your individual medical care. This content is based on peer-reviewed scientific literature and current clinical guidelines available at the time of publication. Every article requires physician review before publication.

Key Takeaways

  • Growth continues rapidly.
  • At this stage there can be a useful combination of fetal size and available fluid around the face.
  • A favorable 3D view may show the forehead, eyelid region, nose, lips, cheeks and chin.
  • A hand, forearm, placenta or uterine wall can sit directly in front of the face.
  • A 3D ultrasound acquisition stores a volume rather than a single flat frame.

Frequently Asked Questions

Is 24 weeks good for 3D ultrasound?

It can be. Published studies report improved facial visualization from around 24 weeks, but no week guarantees a clear image.

Can you see facial expressions at 24 weeks?

4D research has documented movements such as mouthing and yawning at 20 to 24 weeks. These should not be interpreted as adult-like emotions.

Why is part of the face missing?

A limb, placenta, uterine wall, motion or an incomplete fluid interface may prevent a surface from rendering.

References

  1. ACOG. Ultrasound Exams. American College of Obstetricians and Gynecologists. Standard obstetric ultrasound is commonly performed at 18-22 weeks; specialized techniques may include 3D ultrasound. https://www.acog.org/womens-health/faqs/ultrasound-exams
  2. ISUOG Practice Guidelines (updated): performance of the routine mid-trimester fetal ultrasound scan. Ultrasound Obstet Gynecol. 2022;59:840-856. https://www.isuog.org/resource/isuog-practice-guidelines-updated-performance-of-the-routine-mid-trimester-fetal-ultrasound-scan.html
  3. FDA. Ultrasound Imaging. U.S. Food and Drug Administration. Ultrasound does not use ionizing radiation; keepsake images are reasonable when produced during a medically indicated examination without additional exposure. https://www.fda.gov/radiation-emitting-products/medical-imaging/ultrasound-imaging
  4. AIUM. Prudent Clinical Use and Safety of Diagnostic Ultrasound. 2019. Supports prudent, medically appropriate use and attention to acoustic output and exposure time. https://www.aium.org/resources/official-statements/view/prudent-clinical-use-and-safety-of-diagnostic-ultrasound
  5. AIUM. Prudent Use and Safety of Diagnostic Ultrasound in Pregnancy. Official statement. https://www.aium.org/resources/official-statements/obstetric-ultrasound
  6. NHS. 20-week screening scan. The anomaly scan is usually performed between 18 and 21 weeks and assesses fetal anatomy and growth. https://www.nhs.uk/pregnancy/your-pregnancy-care/20-week-scan/
  7. MedlinePlus. Fetal development. U.S. National Library of Medicine. https://medlineplus.gov/ency/article/002398.htm
  8. Connor A, Matthew J, Chung E, Wright R, Rutherford MA. Factors influencing the successful acquisition and quality of three-dimensional souvenir obstetric ultrasound facial images: a narrative review and quantitative evaluation. Ultrasound. 2026. PMID: 42294041. DOI: 10.1177/1742271X261436619. DOI: 10.1177/1742271X261436619 PMID: 42294041 Source
  9. Accuracy and repeatability of fetal facial measurements in 3D ultrasound: A longitudinal study. Early Hum Dev. 2024. PMID: 38701668. DOI: 10.1016/j.earlhumdev.2024.106021. DOI: 10.1016/j.earlhumdev.2024.106021 PMID: 38701668 Source
  10. Three-dimensional sonographic visualization of the fetal face. AJR Am J Roentgenol. PMID: 9456969. DOI: 10.2214/ajr.170.2.9456969. DOI: 10.2214/ajr.170.2.9456969 PMID: 9456969 Source
  11. Two- and three-dimensional sonographic assessment of the fetal face. 1. A systematic analysis of the normal face. Ultrasound Obstet Gynecol. PMID: 15027008. DOI: 10.1002/uog.984. DOI: 10.1002/uog.984 PMID: 15027008 Source
  12. Diagnostic evaluation of the fetal face using 3-dimensional ultrasound. Ultrasound Q. 2008;24:215-223. PMID: 19060688. DOI: 10.1097/RUQ.0b013e31819073c2. DOI: 10.1097/RUQ.0b013e31819073c2 PMID: 19060688 Source
  13. Three-dimensional and four-dimensional ultrasound applications in fetal medicine. Curr Opin Obstet Gynecol. 2009;21:167-174. PMID: 19996869. DOI: 10.1097/GCO.0b013e328329243c. DOI: 10.1097/GCO.0b013e328329243c PMID: 19996869 Source
  14. Role of 3-D ultrasound in clinical obstetric practice: evolution over 20 years. Ultrasound Med Biol. 2015. PMID: 25748522. DOI: 10.1016/j.ultrasmedbio.2014.12.009. DOI: 10.1016/j.ultrasmedbio.2014.12.009 PMID: 25748522 Source
  15. 3D/4D sonography - any safety problem. J Perinat Med. 2016;44:125-129. PMID: 26376219. DOI: 10.1515/jpm-2015-0225. DOI: 10.1515/jpm-2015-0225 PMID: 26376219 Source
  16. 4D ultrasound study of fetal facial expressions at 20-24 weeks of gestation. Int J Gynaecol Obstet. 2014;126:275-279. PMID: 24996686. DOI: 10.1016/j.ijgo.2014.03.036. DOI: 10.1016/j.ijgo.2014.03.036 PMID: 24996686 Source
  17. Fetal face shape analysis from prenatal 3D ultrasound images. Sci Rep. 2024. PMID: 38388522. PMCID: PMC10884000. DOI: 10.1038/s41598-023-50386-9. DOI: 10.1038/s41598-023-50386-9 PMID: 38388522 Source
  18. Three-dimensional ultrasonic images of normal fetus. Study of pregnancies 20-36 weeks; satisfactory recognizable images were reported particularly from 24-34 weeks. PMID page. PMID: 11601189 Source
  19. Three-dimensional ultrasonographic assessments of fetal development. PMID: 9469279. PMID: 9469279 Source
  20. Three-dimensional reconstruction of fetal abnormalities using ultrasonography and magnetic resonance imaging. PMID: 29656679. PMID: 29656679 Source

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