Prolonged pregnancy.

must allow for any discrepancies in gestational age between categories of interest to avoid reaching false conclusions related to neurological outcome. Secondly, it is increasingly difficult to survive at lower gestational ages, and use of neonatal intensive care resources escalates for more immature babies. Unfortunately, resources are not infinite; at some point the costs must outweigh the marginal gain in intact survival, particularly if resources are wasted to the detriment of potential survivors with a much better prognosis. We do not pretend to have the answer as to what lower gestational age represents the cut off point; more experience will help to define such a point if it exists. In any case, individual circumstances will always arise to make such a cut off point nonbinding. What we do wish to indicate is that the neurological outcome for the most immature survivors, of 26 weeks' gestation or less, may be worse than that for more mature survivors of borderline viability, contrary to what has previously been reported. LW DoYLE