Objective: The aim of this study was to determine the apoptotic index using three different apoptotic markers: terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL); M30 cytoDEATH antibody and fluorescein isothiocyanate (FTIC)-labeled annexin-V in the placenta and membranes from normal pregnancy and pregnancy complicated by premature rupture of membranes (PROM). Study design: Placentas from 16 pregnancies (22-40 weeks' gestation) and 13 pregnancies complicated by pPROM and tPROM were collected at delivery. Maternal and gestational age, mode of delivery, gravidity and parity, fetal birthweight, Apgar scores, presence of histologic chorioamnionitis, interval between membrane rupture and delivery were recorded among PPROM and tPROM cases. Results: Only M30 cytoDEATH antibody (P = 0.02) and TUNEL test (P = 0.04) on fetal membranes gave statistically significantly higher levels in cases with premature rupture of membranes. The presence of histologic chorioamnionitis had no significant impact on apoptotic markers in PROM placentas. Preterm deliveries following the rupture of membranes had higher median AI values detected by M30M antibody, compared to those cases delivered without PROM (P = 0.03). Conclusion: High apoptotic nuclei counts were found in fetal membranes of pPROM. © Springer-Verlag 2005.