Editor—We enjoyed reading Morley’s systematic review of the timing of surfactant treatment.1 His overall conclusion that “the data from this systematic review show a 39% reduction in the neonatal mortality if the babies are treated with surfactant at birth compared with a few hours later” is valid only if a number of provisos are taken into account:

The surfactant should be natural or derived from mammalian lungs. The overview contained studies using bovine or porcine surfactants. It cannot be assumed that similar findings apply to the synthetic, protein free surfactants which, both animal studies2 and clinical trials,3 have shown, are not as good as natural surfactants. Exosurf has been studied and early and late treatment compared,4 but not as prophylaxis, and there are no comparative data for ALEC.

Prophylaxis is really treatment given before 15 minutes has elapsed. Prophylactic treatment defined by Morley as “surfactant given down an endotracheal tube at initial resuscitation” did not apply in at least four of the studies …