Related Experiment Video
Updated: Aug 14, 2026
14:19
Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction
Published on: June 29, 2013
Gestational age and fetal biophysical assessment
1Department of Obstetrics and Gynaecology, Grace Maternity Hospital, Halifax, Nova Scotia, Canada.
American Journal of Obstetrics and Gynecology
|February 1, 1988
Summary
Fetal biophysical tests for detecting fetal asphyxia are increasingly used earlier in pregnancy. Results indicate that abnormal test results vary significantly with gestational age, necessitating age-specific interpretation for accurate assessment.
Area of Science:
- Perinatal Medicine
- Fetal Monitoring
- Neonatal Care
Background:
- Improved neonatal care has led to earlier use of biophysical assessments for fetal asphyxia.
- Accurate fetal assessment is crucial for optimizing perinatal outcomes.
Purpose of the Study:
- To evaluate the relationship between gestational age and the abnormality rates of five fetal biophysical variables.
- To determine if fetal biophysical tests require gestational age-specific interpretation.
Main Methods:
- Analysis of 11,012 fetal biophysical assessments in 5582 singleton fetuses with normal perinatal outcomes.
- Evaluation of five variables: nonstress test, fetal breathing movements, fetal movements, fetal tone, and amniotic fluid volume.
- Comparison of abnormality rates across different gestational age groups.
Main Results:
- Nonstress test and fetal breathing movements showed higher abnormality rates between 26-33 weeks' gestation compared to 34-41 weeks.
- Nonstress test, fetal breathing movements, fetal tone, and amniotic fluid volume were more likely abnormal between 42-44 weeks' gestation compared to 37-41 weeks.
- Significant variations in test abnormality rates were observed based on gestational age.
Conclusions:
- Fetal biophysical test results are significantly influenced by gestational age.
- Interpretation of fetal biophysical tests must consider the specific gestational age for accurate detection of fetal asphyxia.
- Gestational age-specific interpretation guidelines are recommended for fetal biophysical assessments.
