Related Experiment Video
Updated: Jun 15, 2025
Author Spotlight: A Focus on Standardized Salivary Gland Ultrasound Protocol in Connective Tissue Disease Research
Published on: October 13, 2023
Comparison of SGA and Severe SGA rates using six size standards - Is there a difference?
Roie Alter1, Adiel Cohen1, Einav Kremer1
1Hadassah Ein Kerem Medical Center, Department of Obstetrics and Gynecology, Jerusalem, Israel.
Insights
The choice of fetal growth standard significantly impacts small for gestational age (SGA) and severe SGA identification rates. Selecting appropriate size standards is crucial for accurate neonatal risk assessment and clinical management.
Area of Science:
- Neonatalogy
- Perinatal Medicine
- Biostatistics
Background:
- Small for gestational age (SGA) neonates face increased morbidity risks.
- Existing SGA size standards may lack generalizability due to diverse designs and populations.
- Uncertainty exists regarding the optimal standard for identifying SGA fetuses.
Purpose of the Study:
- To evaluate variations in SGA and severe SGA rates using six different fetal size standards.
- To compare the diagnostic performance of various international and local growth charts.
- To highlight the clinical implications of differing SGA identification rates.
Main Methods:
- Retrospective cohort study of over 32,000 singleton deliveries.
- Defined SGA and severe SGA based on birthweight percentiles (10th and 3rd) using six distinct growth standards.
- Included Hadlock, FMF, WHO, IG-21, and two local population-based standards.
Main Results:
- Significant variations in SGA and severe SGA rates were observed across the evaluated standards.
- WHO criteria identified 16.9% SGA, while INTERGROWTH-21 identified only 5.2%.
- FMF charts identified 6.37% severe SGA, contrasted with 1% by local charts (p < 0.001 for both).
Conclusions:
- The selection of a fetal growth standard critically influences SGA and severe SGA identification.
- Discrepancies in rates underscore the need for careful consideration of chosen size standards in clinical practice.
- Standardization or careful selection of size standards is essential for consistent neonatal care.
Background:
Small for gestational age (SGA) neonates are known to be at an elevated risk for neonatal morbidity. Despite this, there is a growing array of proposed size standards for identifying SGA fetuses. Given the inherent differences in design, acquisition methods, and the characteristics of the populations they represent, the generalizability of these standards to diverse populations remains uncertain.
Introduction:
This study aimed to assess variations in rates of SGA and severe SGA using six distinct size standards: Hadlock, Fetal Medicine Foundation (FMF), World Health Organization (WHO), Intergrowth-21 (IG-21), and two locally derived population-based size standards. The objective was to examine the differences in SGA and severe SGA rates among these size standards.
Methods:
A retrospective cohort study was conducted, encompassing all singleton deliveries in two tertiary referral hospital campuses with an annual birth count exceeding 10,000, from January 2019 to July 2022. SGA and severe SGA were defined as birthweights below the 10th or 3rd percentile, respectively, based on each growth standard. The study design included details on the setting, subjects (singleton deliveries), and the chosen size standards. Comparative analyses were performed to assess variations in SGA and severe SGA rates among these size standards.
Results:
Our study analyzed 32,912 singleton deliveries. We found that the choice of growth standard significantly impacted the rates of both SGA and severe SGA infants. Notably, the WHO criteria identified 5,548 (16.9 %) fetuses as SGA, compared to only 1,716 (5.2 %) using the INTERGROWTH-21 standard (p < 0.001). Similarly, for severe SGA, the FMF charts classified 2098 (6.37 %) infants, significantly higher than the 320 (1 %) identified by Dolberg's local population-based charts (p < 0.001).
Conclusion:
Our study demonstrates a significant variety of SGA and severe SGA rates using different size standards. Therefore, the decision on the size standards in use is critical given the significant influence on clinical management.
Synopsis:
There are significant variations in SGA and Severe SGA rates depending on the chosen size standard.
Related Concept Videos
01:15One-Way ANOVA: Unequal Sample Sizes
01:15One-Way ANOVA: Equal Sample Sizes
Different sample means can result in different values for the variance estimate: variance between samples. This is because the variance between samples is calculated as the product of the sample size and the variance between the...
01:19Testing a Claim about Standard Deviation
The hypothesis testing for the claim of population standard deviation (or variance) requires the data and samples to be random and unbiased. The population distribution also must be normal. There is no specific requirement on the sample size as the estimation is based on the chi-square distribution.
As a first step, the hypothesis (null and alternative) concerning the claim about...
01:19Sieve Analysis and Grading Curves
01:10Standard Deviation
01:13Range Rule of Thumb to Interpret Standard Deviation
For instance, the range rule of thumb can be used to find the tallest and the shortest student in a class, given the mean student height and standard deviation. If the mean student height is 1.6 m and the standard deviation, s is 0.05 m, the height...