New treatment of early fetal chylothorax.

OBJECTIVE: To evaluate OK-432, a preparation of Streptococcus pyogenes, in the treatment of early fetal chylothorax. METHODS: A prospective study of all fetuses (n=7) with persistent early chylothorax (gestational ages 16-21 weeks) referred to the tertiary center of fetal medicine in Denmark in 2003-2005. Fetuses were injected with 0.2-1.0 mg of OK-432 into the pleural cavity. The treatment was repeated if there were persistent or increasing pleural effusions after 1-3 weeks. The main outcome measures included remission of pleural effusions and fetal and infant morbidity and mortality. RESULTS: Total remission of pleural effusions was obtained in all fetuses after one or two intrapleural injections of OK-432. No adverse effects of the treatment were observed. No fetus developed hydrops, and all experienced an uncomplicated third trimester. All children were born healthy without pleural effusions, lung hypoplasia, or hydrops. CONCLUSION: Persistent early chylothorax is a condition with a high mortality rate and no established treatment option. Use of OK-432 is a promising therapy for selected fetuses with persistent chylothorax early in the second trimester.