[Current approach in preterm prelabor rupture of membranes: new definitions? Is CRP determination useful? Are alternatives in sight?].

Around 3% of all pregnancies are complicated by preterm prelabor rupture of membranes (PPROM) before 37 + 0 weeks of gestation. Since PPROM is likely to be associated with microbial invasion of the amniotic cavity (MIAC)-either before or secondary to PPROM-the risk of developing intraamniotic inflammation (IAI) is high. IAI is associated with short latency to delivery and with adverse short- and long-term outcomes for the newborn, especially in cases of fetal inflammatory response syndrome (FIRS). Prediction of IAI based on maternal parameters is difficult or impossible. The recently established definition of triple I ("infection, inflammation, or both") is based on the parameter "maternal body temperature". If this is increased to ≥ 38.0 °C and there is no other reason to explain maternal fever, the finding is suspicious for triple I if at least one other of the following parameters can be found: fetal tachycardia > 160 bpm for at least 10 min, maternal leukocytes > 15,000/µl without administration of corticosteroids, or purulent fluid from the cervical os. Pregnancies suspicious for triple I should be terminated. The confirmation of triple I is only possible by placental histology (histologically confirmed chorioamnionitis, HCA). Confirmation based on amniocentesis (positive Gram stain, low glucose concentration [<14 mg/dl], elevated white blood cell count [>30 cells/mm], positive culture) takes too long and is unreliable. Serial determinations of C‑reactive protein also do not allow reliable diagnosis of IAI. Studies using interleukin 6 measurements from the posterior fornix and/or cervical os are promising methods, the validation of which is awaited.