Background Surfactant (SF) replacement therapy, reduces mortality and pulmonary complications in ventilated infants with RDS. Controversy exists regarding the recommended number of SF doses in current literature.

Objective Identification of maternal predisposing factors associated with the necessity of a second or a third dose SF replacement therapy in preterm neonates.

Materials and Methods We retrospectively studied 142 neonates with gestational age (GA) between 25–32 weeks that were treated with prophylactic administration of SF. Neonates were divided in two groups according to the doses of SF (group A: one dose and the group B: ⩾2 doses). Possible prenatal risk factors were registered for each mother prospectively (age, chorioamnionitis, premature rupture of membranes, maternal diabetes, smoking, preeclampsia, and prenatal administration of corticosteroids).

Results The collected data included 142 neonates, 32 (22.5%) of them received ⩾2 doses of SF (group B). The impact of mother’s chorioamnionitis was noticed in 31.3% (10 out of 32) of neonates who received more than 1 dose of SF vs 15.5% in group A (p = 0.04). Maternal age represents another factor related to the administration of ⩾2 doses of SF although no statistical significant difference was found between the 2 groups (p = 0.09). The other parameters of our study didn’t differ significantly between the 2 groups.

Conclusions Chorioamnionitis represents the only maternal factor which is steadily related to the administration of multiple doses of SF. Further studies are required to demonstrate if the necessity of multiple doses of SF are related only to RDS and/or to other possible risk factor.