Prenatal lung-head ratio: threshold to predict outcome for congenital diaphragmatic hernia

J Matern Fetal Neonatal Med. 2012 Jul;25(7):1011-6. doi: 10.3109/14767058.2011.608442. Epub 2011 Oct 4.

Abstract

Objective: The literature suggests that lung-head ratio (LHR) and liver position may inconsistently predict outcome for congenital diaphragmatic hernia (CDH). We reviewed our inborn neonates with isolated left-sided CDH to determine whether these variables predicted survival and to estimate the optimal LHR threshold.

Methods: Prenatal LHR and liver position were obtained from 2002 to 2009. The primary endpoint was survival.

Results: LHR was greater in survivors after adjusting for gestational age (median 1.40 versus 0.81; p < 0.001). LHR demonstrated excellent diagnostic discrimination, with area under receiver operating characteristic (ROC) curve 0.93 (95% CI 0.86-0.99). LHR threshold of 1.0 was 83% sensitive and 91% specific in predicting survival. An optimal LHR threshold of 0.85 predicted survival with 95% sensitivity and 64% specificity, reducing false negatives (survivors with low LHR). LHR > 0.85 predicted survival after adjustment for gestational age (OR = 33.6, 95% CI = 5.4-209.5). Liver position did not predict survival.

Conclusions: Prenatal LHR >0.85 predicts survival for infants with isolated left-sided CDH without compromising discrimination of survivors from non-survivors. The diagnostic utility of LHR may be confounded by gestational age at measurement. Stringent LHR threshold may minimize false-negative attribution and improve utility of this measurement as predictor of survival.

MeSH terms

  • Female
  • Head / diagnostic imaging
  • Hernia, Diaphragmatic / diagnostic imaging
  • Hernia, Diaphragmatic / mortality
  • Hernias, Diaphragmatic, Congenital*
  • Humans
  • Liver / diagnostic imaging
  • Lung / diagnostic imaging
  • Male
  • New York City / epidemiology
  • Pregnancy
  • Retrospective Studies
  • Ultrasonography, Prenatal