OBJECTIVE: To determine the validity of existing imaging-derived formulas for predicting the fetal lung volume (FLV). METHODS: In a consecutive series of postmortem lungs without pulmonary anomalies, the observed FLV (FLV(obs)) after inflation was correlated with individual fetal variables used in imaging-derived formulas. In addition, FLV(obs) was correlated with the predicted FLV calculated according to these same formulas. RESULTS: Postmortem FLV(obs) showed a strong correlation with estimated fetal body weight, biparietal diameter, and head circumference (r > 0.9). The correlation of FLV(obs) with gestational age, femur length, and liver weight was less strong (0.8 < r < 0.9). The correlation was strongest for midgestation fetuses (between 22 and 32 weeks' gestation). The predicted FLV calculated using formulas based on fetal body weight, biparietal diameter, and head circumference showed the strongest correlation with the actual FLV(obs) (r > 0.9). CONCLUSIONS: Postmortem FLV(obs) strongly correlates with fetal body weight, biparietal diameter, and head circumference, especially in midgestation fetuses. Regression formulas based on these fetal variables provide the most accurate prediction of FLV. Copyright 2003 S. Karger AG, Basel
OBJECTIVE: To determine the validity of existing imaging-derived formulas for predicting the fetal lung volume (FLV). METHODS: In a consecutive series of postmortem lungs without pulmonary anomalies, the observed FLV (FLV(obs)) after inflation was correlated with individual fetal variables used in imaging-derived formulas. In addition, FLV(obs) was correlated with the predicted FLV calculated according to these same formulas. RESULTS: Postmortem FLV(obs) showed a strong correlation with estimated fetal body weight, biparietal diameter, and head circumference (r > 0.9). The correlation of FLV(obs) with gestational age, femur length, and liver weight was less strong (0.8 < r < 0.9). The correlation was strongest for midgestation fetuses (between 22 and 32 weeks' gestation). The predicted FLV calculated using formulas based on fetal body weight, biparietal diameter, and head circumference showed the strongest correlation with the actual FLV(obs) (r > 0.9). CONCLUSIONS: Postmortem FLV(obs) strongly correlates with fetal body weight, biparietal diameter, and head circumference, especially in midgestation fetuses. Regression formulas based on these fetal variables provide the most accurate prediction of FLV. Copyright 2003 S. Karger AG, Basel