Two infants with features of severe beta adrenergic blockade, pericard
ial effusions, and myocardial hypertrophy were born to mothers receivi
ng long term treatment with oral labetalol for hypertension in pregnan
cy. Labetalol was implicated in the aetiology of these problems. Peric
ardial effusion and myocardial hypertrophy have not been associated wi
th labetalol toxicity in neonates.