Can a cyclo-oxygenase type-2 selective tocolytic agent avoid the fetal side effects of indomethacin?

We evaluated the efficacy and safety of nimesulide (100 mg orally twice dai ly for > 48 hours) in a pilot series of five women (two with twin pregnanci es) at 24(+6) weeks (range 21(+3)-27(+2)) in preterm labour which was unres ponsive to intravenous ritodrine. Nimesulide therapy was continued for eigh t days (5-16) and was associated with a prolongation of pregnancy of 27 day s (6-69). Oligohydramnios occurred in all seven fetuses after three to nine days of therapy, and in the five pregnancies that continued after disconti nuation of nimesulide, it resolved within four days (2-7). None of the babi es manifested permanent renal damage.