“…The most commonly used method to assess fetal lung volume, and subsequent outcomes, is the measurement of lung area to head circumference ratio (LHR) with the use of 2-dimensional ultrasound (US) (Metkus et al, 1996;Sbragia et al, 2000;Laudy et al, 2003;Heling et al, 2005;Jani et al, 2006a;Hedrick et al, 2007;S.H. Yang et al, 2007;Sinha et al, 2009).…”