MATERNAL-FETAL MEDICINE Practicability of vaginal washing fluid creatinine level in detecting premature rupture of membranes Leila Sekhavat • Raziah Dehghani Firouzabadi • Prisa Mojiri Received: 3 September 2011 / Accepted: 16 January 2012 / Published online: 25 January 2012 Ó Springer-Verlag 2012 Abstract Objective The purpose of this study was to evaluate the reliability of vaginal washing fluid creatinine level for the diagnosis of premature rupture of membranes (PROM). Method A prospective diagnostic study performed in Shahid Sedoughi Hospital on 160 pregnant women (30 definite PROM, 30 no PROM and 100 suspected PROM) at 28–40 weeks of gestation. The vagina was washed by injection with a syringe filled with 3 ml of saline solution, and the washing fluid was collected from the posterior vaginal fornix and send to laboratory. Creatinine values in vaginal washing were measured and compared. Result The mean vaginal fluid creatinine levels in definite PROM group, suspected PROM and no PROM were 0.40 ± 0.20, 0.16 ± 0.04 and 0.08 ± 0.01 mg/dl, respec- tively, where the difference was statistically significant (P = 0.001). The sensitivity, specificity, positive and negative predictivity values and accuracy were 98.7, 100, 100, 98.8 and 87.1%, respectively, in detecting PROM by evaluation of vaginal fluid creatinine concentration with cut-off value of 0.14 mg/dl. Conclusion This study showed that creatinine determi- nation in vaginal washing fluid is a useful marker for PROM diagnosis. It is a reliable, simple, cheap and rapid test. Keywords Premature rupture of membrane (PROM) Á Vaginal washing fluid Á Creatinine Introduction Premature rupture of membranes (PROM) is defined as the rupture of chorioamniotic membranes prior to the onset of labor and occurs in 10% of all gestations and about 2–4% of preterm pregnancies, with complications such as infection and preterm birth [1–3]. PROM is the cause of approximately one-third of preterm deliveries. It increases the risk of pre- maturity and leads to a number of other perinatal and neonatal complications, including a 1–2% risk of fetal death [4]. The diagnosis of PROM is sometimes challenging. A false positive diagnosis of PROM may lead to inappropriate intervention and a false negative diagnosis of PROM may cause maternal morbidities [5]. Diagnosis of PROM is easy when the rupture is obvious but difficult and indeed impossible when the rupture is minimal. The diagnosis of PROM requires a thorough history, physical examination, and selected laboratory studies [4]. For decades, a combi- nation of visual pooling of amniotic fluid during speculum examination, alkaline pH determination and microscopic evidence of ferning has been widely used to determine rupture of membranes. Furthermore; these tests are prone to false positive results secondary to vaginal contamination with blood, urine, or semen [6]. To reduce false positive rates, several biochemical markers in the vaginal fluids have been studied, including alpha fetoprotein (AFP), human chorionic gonadotropin (hCG), prolactin, and fibronectin; and alpha microglobulins have been used in clinical studies to diagnose PROM [4, 7–10]. Such tests are based primarily on the identification in the cervicovaginal discharge of one or more biochemical markers that are present in the setting L. Sekhavat (&) Á P. Mojiri Shahid Sadoughi University of Medical Sciences, Yazd, Iran e-mail: sekhavat@ssu.ac.ir; lsekhavat@yahoo.com R. D. Firouzabadi Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran 123 Arch Gynecol Obstet (2012) 286:25–28 DOI 10.1007/s00404-012-2233-6