Assessment of lung area in normal fetuses at 12-32 weeks

C. F A Peralta, P. Cavoretto, B. Csapo, H. Vandecruys, K. H. Nicolaides

Research output: Contribution to journalArticlepeer-review


Objective: To establish reference intervals with gestation for the right and left lung areas and lung area to head circumference ratio (LHR). Methods: This was a cross-sectional study of 650 normal singleton pregnancies at 12-32 weeks of gestation. We measured the left and right lung areas on the cross-sectional plane of the thorax, used for examination of the four-chamber view of the heart, by three different techniques: firstly, manual tracing of the limits of the lungs; secondly, multiplication of the longest diameter of the lung by its longest perpendicular diameter; thirdly, multiplication of the anteroposterior diameter of the lung at the mid-clavicular line by the perpendicular diameter at the midpoint of the anteroposterior diameter. Results: The respective mean left and right lung areas (manual tracing) increased with gestational age, from 36 and 58 mm2 at 12 weeks to 220 and 325 mm2 at 20 weeks and 594 and 885 mm2 at 32 weeks. This 16-fold increase in lung area was accompanied by a four-fold increase in head circumference. Consequently, the left and right LHR increased with gestational age. The most reproducible way of measuring the lung area was by manual tracing of the limits of the lungs and the least reproducible was by multiplying the longest diameter of the lungs by their longest perpendicular diameter. Furthermore, the method employing the longest diameter, compared with the tracing method, overestimated both the left and the right lung areas by about 45% and the method employing the anteroposterior diameter overestimated the area of the right lung by about 35%, but not that of the left lung. Conclusions: In the antenatal prediction of pulmonary hypoplasia by the assessment of lung area it is important to take gestational age into account. Dividing the lung area by the head circumference does not correct for the gestation-related increase in lung area. Reproducible measurement of the lung area is provided by manual tracing of the limits of the lungs, rather than by multiplication of lung diameters.

Original languageEnglish
Pages (from-to)718-724
Number of pages7
JournalUltrasound in Obstetrics and Gynecology
Issue number7
Publication statusPublished - Dec 2005


  • Diaphragmatic hernia
  • Lung area
  • Lung-to-head ratio
  • Pulmonary hypoplasia
  • Ultrasonography

ASJC Scopus subject areas

  • Obstetrics and Gynaecology
  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology
  • Reproductive Medicine
  • Acoustics and Ultrasonics


Dive into the research topics of 'Assessment of lung area in normal fetuses at 12-32 weeks'. Together they form a unique fingerprint.

Cite this