Premature rupture of membranes with oligo- or anhydramnios before 24 weeks of gestation and the chances of fetal survival

Rupture of the membranes before the fetus has achieved viability within the womb is an event of enormous importance for both mother and physician. The potential outcome ranges from fetal death, a frequent occurrence, to a severely disabled life or a happy (but rare) birth without any mental or physical retardation for the child. The aim of the present investigation was to provide the consulting physician with valid data, enabling him/her to make a realistic assessment of the risks and to inform the patient accordingly. METHOD: In a retrospective analysis, we followed 36 cases with spontaneous rupture of the maternal membranes and development of oligoanhydramnios and anhydramnios before 24 weeks of gestation. The patients had been treated between January 1994 and 2004. In a more detailed assessment, the patient cohort was divided into one group of women with rupture between 10 and 20 weeks of gestation and another group with a gestational age between start of week 21 and end of week 23. RESULTS: Of the 36 children, seven (19.4%) survived initially, with two of the seven survivors dying subsequently. Among women with amniorrhexis before week 21 of gestation, only three of the 26 children survived, while four of 10 children survived among women with premature rupture of membranes between 21 and 23 weeks of gestation (p = 0.053) No case of mental retardation could be observed in the surviving children. Perinatal outcome was found to be significantly different in the presence of amnionitis (3 of 27) compared to the group without this event (4 of 9) (p = 0.028). CONCLUSIONS: Because of the poor fetal outcome, termination of an ongoing pregnancy must also be considered in counseling the mother. If the mother decides to continue her pregnancy, amnionitis will be the most critical factor for ultimate termination of pregnancy.