Outcome after prenatal diagnosis of the hypoplastic left heart syndrome.

OBJECTIVE: To derive accurate survival figures in the current surgical era for counselling in early pregnancy after the diagnosis of fetal hypoplastic left heart syndrome.
SETTING: A tertiary referral centre for paediatric cardiology and cardiac surgery.
DESIGN: A retrospective study of the outcome in all cases of hypoplastic left heart syndrome presenting in fetal life between mid-1993 and the end of 1996. PATIENTS: The diagnosis was made in 30 fetuses. In four of 12 identified before 24 weeks' gestation the mothers chose to terminate the pregnancy. There was an intention to treat in 24 of the remaining fetuses. MAIN OUTCOME MEASURE: Survival to six months of postnatal life.
RESULTS: Of the 24 infants, five were not offered Norwood stage 1 because of trisomy 18 (n = 2), unfavourable cardiac anatomy (n = 2), or neurological impairment (n = 1). One further infant did not survive to cardiac surgery after gastrointestinal surgery. Of the remaining 18 patients, eight had features that were considered to increase the risk of surgical repair. Of the 18 patients who underwent Norwood stage 1, there were nine survivors. There was a survival rate of 70% in infants undergoing surgery with no complicating features, a 50% survival of the all surgical candidates, and 37.5% survival from an intention to treat position.
CONCLUSIONS: At the initial diagnosis of fetal hypoplastic left heart syndrome, the overall survival appears to be less than 40%. Evaluation must include detailed extracardiac and intracardiac assessment to predict the risks of surgical treatment. Prenatal counselling can be modified as pregnancy advances, depending on the detection or exclusion of complicating factors.