Date	Event	Description
16 February 2010	New search has been performed	This updates the review "Prophylactic natural surfactant extract for preventing morbidity and mortality in preterm infants" published in the Cochrane Database of Systematic Reviews, Issue 4, 1997 (Soll 1997). Updated search in January 2010 revealed one additional study. Subgroup analyses based on surfactant product added. Risk of Bias tables completed. Methods section updated. No change to conclusions of the review.
27 August 1997	New citation required and conclusions have changed	Substantive amendment