Reading Ultrasound Reports: A Guide to Common Terms and Abbreviations

Getting a copy of your ultrasound report can feel like reading a different language — dense with abbreviations and clinical terminology. While your doctor will walk you through the results, understanding the basic terms yourself can help you feel more informed and ask better questions.

Common Measurement Abbreviations

• GA (Gestational Age) — how far along the pregnancy is, calculated from the last menstrual period or ultrasound measurements.
• EDD (Estimated Due Date) — the calculated expected delivery date.
• CRL (Crown-Rump Length) — a measurement from head to bottom, commonly used for dating in early pregnancy.
• BPD (Biparietal Diameter) — a measurement across the baby's head, used to assess growth.
• HC (Head Circumference) — the measurement around the baby's head.
• AC (Abdominal Circumference) — the measurement around the baby's abdomen.
• FL (Femur Length) — the measurement of the thigh bone, another key growth indicator.
• EFW (Estimated Fetal Weight) — a calculated weight estimate based on several measurements combined.

Placenta and Fluid Terms

• Placenta location — often described as anterior (front), posterior (back), fundal (top), or low-lying.
• AFI (Amniotic Fluid Index) — a measurement estimating amniotic fluid volume.
• Placenta previa — when the placenta covers or is very close to the cervix; this is monitored and often resolves as the pregnancy progresses in many cases.

Position and Presentation Terms

• Cephalic/vertex — head-down position, the typical position for delivery.
• Breech — bottom or feet positioned to deliver first.
• Transverse — positioned sideways across the uterus.
• Anterior/posterior — often refers to which way the baby's back is facing.

Practical tip: Position terms (especially before the third trimester) describe a snapshot in time, not a fixed prediction — babies frequently change position throughout pregnancy, particularly before the final weeks when space becomes more limited.

Percentile and Growth Terms

• Percentile — shows how your baby's measurements compare to a reference population at the same gestational age (for example, a measurement at the 50th percentile is right in the middle of the typical range).
• IUGR (Intrauterine Growth Restriction) — a term used when growth measurements fall notably below expected ranges, prompting closer monitoring.
• LGA (Large for Gestational Age) — when measurements are notably above expected ranges.

Other Common Terms

• FHR (Fetal Heart Rate) — your baby's heart rate, typically recorded during the scan.
• NT (Nuchal Translucency) — the measurement taken during first-trimester screening.
• Doppler — a specific ultrasound technique used to assess blood flow, sometimes through the umbilical cord or specific vessels.

What to Do If You Don't Understand Something on Your Report

• Ask your doctor directly to explain any term or measurement you're unsure about — this is a completely reasonable and common request.
• Avoid searching individual technical terms in isolation online, since context (your complete results together) matters significantly for accurate interpretation.
• Request a copy of your report for your own records if you'd like to review it alongside your doctor's explanation.

Frequently Asked Questions

Should I be worried if a measurement isn't exactly at the 50th percentile?
No — a wide range of percentiles is considered entirely normal. Doctors look at overall patterns and trends over time rather than expecting every measurement to land precisely at the midpoint.

Why do some reports have more abbreviations than others?
Report detail and format can vary by clinic, equipment, and the specific type of scan performed — a routine growth check may generate a simpler report than a comprehensive anatomy scan.

Can I request my ultrasound images or report to keep?
Many clinics can provide printed images or a copy of your report upon request — policies vary, so it's worth asking your specific provider.

Is it normal for measurements to be slightly different between visits or providers?
Yes, minor measurement variation is normal given the nature of ultrasound technology and even slight differences in positioning or technique — your doctor factors this into their overall assessment rather than relying on any single number in isolation.

---

Medical Disclaimer: This article is intended for general informational purposes only and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified doctor regarding your individual ultrasound results or pregnancy monitoring plan.