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Congenital left heart obstruction: ethnic variation in incidence and infant survival
  1. Elza Cloete1,
  2. Lynn Sadler2,
  3. Frank H Bloomfield1,
  4. Sue Crengle3,
  5. Teuila Percival4,
  6. Thomas L Gentles5
  1. 1 Liggins Institute, University of Auckland, Auckland, New Zealand
  2. 2 Department of Obstetrics and Gynaecology, National Women’s Hospital, Auckland, New Zealand
  3. 3 Department of Preventative and Social Medicine, University of Otago, Dunedin, New Zealand
  4. 4 Kidz First Children’s Hospital, Auckland, New Zealand
  5. 5 Greenlane Paediatric and Congenital Cardiac Service, Starship Hospital, Auckland, New Zealand
  1. Correspondence to Dr Elza Cloete, Liggins Institute, University of Auckland, Auckland 1142, New Zealand; elzac{at}


Objective To investigate the relationship between ethnicity and health outcomes among fetuses and infants with congenital left heart obstruction (LHO).

Design A retrospective population-based review was conducted of fetuses and infants with LHO including all terminations, stillbirths and live births from 20 weeks’ gestation in New Zealand over a 9-year period. Disease incidence and mortality were analysed by ethnicity and by disease type: hypoplastic left heart syndrome (HLHS), aortic arch obstruction (AAO), and aortic valve and supravalvular anomalies (AVSA).

Results Critical LHO was diagnosed in 243 fetuses and newborns. There were 125 with HLHS, 112 with AAO and 6 with isolated AVSA. The incidence of LHO was significantly higher among Europeans (0.59 per 1000) compared with Māori (0.31 per 1000; p<0.001) and Pacific peoples (0.27 per 1000; p=0.002). Terminations were uncommon among Māori and Pacific peoples. Total case fatality was, however, lower in Europeans compared with other ethnicities (42% vs 63%; p=0.002) due to a higher surgical intervention rate and better infant survival. The perinatal and infant mortality rate was 82% for HLHS, 15% for AAO and 2% for AVSA.

Conclusion HLHS carries a high perinatal and infant mortality risk. There are ethnic differences in the incidence of and mortality from congenital LHO with differences in mortality rate suggesting inequities may exist in the perinatal management pathway.

  • congenital anomaly
  • cardiac disease
  • ethnic disparity
  • incidence
  • pregnancy outcomes

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  • Contributors EC conceptualised and designed the study, carried out the analysis, drafted the initial manuscript and reviewed and revised the manuscript. TG, LS and FHB assisted with the design of the study, provided supervision over all aspects of the study and reviewed and revised the manuscript. SC and TP reviewed and revised the manuscript and provided guidance with the interpretation of data related to Maori and Pacifica. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

  • Funding This research was supported by grants from the Health Research Council of New Zealand and Gravida Centre for Growth and Development.

  • Competing interests None declared.

  • Ethics approval This population-based audit was approved by the Health and Disability Ethics Committees of New Zealand (MEC/12/EXP/077/AM02).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Patient consent for publication Not required.

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