Fetal Growth Percentile Calculator

Estimate fetal growth and identify potential risks based on ultrasound measurements.

Gestation (Weeks) Current week of pregnancy.

Abdominal Circumference (AC, mm) From ultrasound biometry.

Femur Length (FL, mm) From ultrasound biometry.

Biparietal Diameter (BPD, mm) From ultrasound biometry.

Fetal Growth Analysis

Growth Percentile (%)

Estimated Fetal Weight (g)

Status (SGA/AGA/LGA)

Fetal Development Interpretation

Percentiles indicate the baby's size relative to gestational age.

Monitoring Fetal Development with Ultrasound Biometry

The **Fetal Growth Percentile Calculator** is a valuable resource used after an **ultrasound biometry** scan to track **fetal development** and assess the risk of growth disorders. It requires standard measurements like **Abdominal Circumference (AC)**, **Femur Length (FL)**, and **Biparietal Diameter (BPD)** to first calculate the **Estimated Fetal Weight (EFW)**, and then compare that weight against norms to determine the percentile.

Calculating EFW and Growth Percentile

The calculation is complex, using the **Hadlock formula** (or a similar accepted regression model) to estimate weight in grams based on the ultrasound measurements. The formula is:

$$\log_{10}(\text{EFW}) = 1.3596 + 0.00064(\text{AC} \times \text{FL}) + 0.00061(\text{BPD}) + \dots$$

Once the **Estimated Fetal Weight (EFW)** is calculated, the **Fetal Growth Percentile** is determined by comparing the **EFW** to the established median weight for that specific gestational week. This provides the most comprehensive **pregnancy tracker** data.

Interpreting SGA, AGA, and LGA Status

The **Fetal Growth Percentile** is categorized to identify potential risks:

**SGA (Small for Gestational Age):** Below the $10$th percentile. Requires close monitoring for restricted growth.
**AGA (Appropriate for Gestational Age):** Between the $10$th and $90$th percentiles. Considered normal **fetal development**.
**LGA (Large for Gestational Age):** Above the $90$th percentile. May indicate maternal diabetes or other complications.

Always share the results from this **Fetal Growth Percentile Calculator** and your **ultrasound biometry** data with your healthcare provider.

Fetal Growth FAQs

What does a Fetal Growth Percentile of 50% mean?

A **Fetal Growth Percentile** of $50\%$ means the fetus's **Estimated Fetal Weight (EFW)** is exactly average for its **gestational age**. This falls squarely within the **AGA** (Appropriate for Gestational Age) range and indicates normal **fetal development**.

Is the estimated weight from ultrasound biometry always accurate?

No. The **Estimated Fetal Weight (EFW)** derived from **ultrasound biometry** is an estimate and can have an error margin of $\pm 15\%$. However, serial measurements taken over time provide the most reliable way to track the **Fetal Growth Percentile** trend.

What are AC, FL, and BPD?

**AC (Abdominal Circumference)**, **FL (Femur Length)**, and **BPD (Biparietal Diameter)** are the primary measurements used during **ultrasound biometry** to calculate the volume and **Estimated Fetal Weight (EFW)** of the fetus for **Fetal Growth Percentile** determination.