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 daily for > 48 hours) in a pilot series of five women (two with twin pregnancies) at 24(+6) weeks (range 21(+3) - 27(+2)) in preterm labour which was unresponsive to intravenous ritodrine. Nimesulide therapy was continued for eight days (5-16) and was associated with a prolongation of pregnancy of 27 days (6-69). Oligohydramnios occurred in all seven fetuses after three to nine days of therapy, and in the five pregnancies that continued after discontinuation of nimesulide, it resolved within four days (2-7). None of the babies manifested permanent renal damage.