increasing fetal physical activity followed by urination or preliminary bladder emptying. CONCLUSIONS The normal lower urinary tract hydrodynamic parameters of the control group are absolutely necessary for comparing the same parameters in cases of fetal urinary tract abnormalities or complicated pregnancy. # S09-2 (O) URINARY FLOW PATTERN IN PREMATURE BOYS AT THE 32TH GESTATIONALWEEK L.Henning OLSEN 1 , Ingrid GROTHE 2 , Yazan F. RAWASHDEH 3 and Troels M. JOERGENSEN 4 1 Aarhus Univ. Hospital - Skejby, Ped. Urology, Aarhus, DENMARK, 2 Aarhus University Hospital - Skejby, Urology - Research Unit, Aarhus, DENMARK, 3 Aarhus University Hospital - Skejby, Ped. Urology, Aarhus, DENMARK, 4 Aarhus University Hospital - Skejby, Ped. Urol, Aarhus, DENMARK PURPOSE The voiding of healthy newborn boys shortly after term is dominated by dyscoordinated flow patterns (Olsen et al. J Urol in press) and continues to do so during the first year of life (Olsen et al. J Ped Urol 2008). This study addresses the flow patterns of premature boys. MATERIAL AND METHODS The parents of 29 otherwise healthy premature males accepted to let their child participate in the study. Flow measurements were carried out using an ultrasound flow probe device during a 4-hour observation period. Flow patterns were assessed according to the definitions of the ICCS. Data of 25 boys (median gestational age/weight at birth: 31.3 weeks/1590 g) with 98 micturitions where applicable for analysis. Results are reported as median (range). RESULTS On examination median age was 10 (3-42) days. Flow patterns were bell-shaped in 48%, interrupted in 44%, staccato in 6% and plateau in 2%. In nine of the 47 bell-shaped curves (19%) some fluctuations occurred though not fulfilling the criteria of staccato. None of the premies with more than one recorded micturition had bell- shaped curves only. The number of coordinated flows was not correlated to the age (r2 0.016, P ¼ 0.6). Subjects voided 0.7 (0.2-3.6) times/hour with a volume of 3.9 (0.6-25.2) mL. Median Qmax was 1.0 (0.3-10.0) mL/s. CONCLUSIONS Male premies void with a high degree of dyscoordination, small volumes and Qmax values indicating incomplete bladder emptying. Dyscoordinated voiding seems to be part of the natural development of voiding function. This study supports the observations made in mature newborns and during infancy showing maturational voiding coordination. # S09-3 (PP) IS CYSTATIN-C A RELIABLE PROGNOSTIC PARAMETER IN TERMS OF RENAL FUNCTIONAL RESERVE FOR ANTENATALLY DIAGNOSED INFRAVESICAL OBSTRUCTION? O ¨ mer ACAR 1 , Nihat ULUOCAK 2 , Orhan ZIYLAN 1 , Ibrahim KALELIOGLU 3 , Atil YU ¨ KSEL 3 and Haluk ANDER 1 1 Istanbul University, Istanbul Faculty of Medicine, Department of Urology, Istanbul, TURKEY, 2 Gaziosmanpasa University, School of Medicine, Department of Urology, Tokat, TURKEY, 3 Istanbul University, Istanbul Faculty of Medicine, Department of Obstetrics and Gynecology, Istanbul, TURKEY PURPOSE We investigated the prognostic power of cystatin-c in determining renal functional outcome in patients with antenatally diagnosed infravesical obstruction (IVO). MATERIAL AND METHODS A total of 10 fetuses (IVO group) with prenatal ultrasonographic findings of bladder outlet obstruction were enrolled to this study.Amniotic fluid and fetal urine samples were obtained in IVO group. Control group consisted of 25 fetuses, who have undergone amniocentesis for obstetric reasons.Three consecutive bladder punctures (48 hours apart) were performed to obtain fetal urine sample. In addition to standart prognostic parameters (sodium, chloride, calcium, protein, beta-2 microglobulin, osmolarity), cystatin-c was measured both in urine and amniotic fluid samples. RESULTS Mean maternal age was 26.9 (22-33) years in IVO group and 28.2 (22-34) years in control group (p > 0.05). In IVO group (n ¼ 10), 9 fetuses with poor prognostic parameters died either in-utero (n ¼ 4) or early postnatally (n ¼ 5). The only fetus with favorable parameters survived postnatally. His serum creatinine level was 0.2 mg/dl at 1 year follow-up after valve ablation. Mean fetal urine levels of cystatin-c was 1.59  1.87, 1.39  1.76 and 1.68  1.79 mg/l in serial punctures. The difference between second and third bladder punctures was significant in terms of urine cystatin-c level (p ¼ 0.015). Mean amniotic fluid cystatin-c level was 2.11  0.4 mg/l in IVO group and 1.12  0.20 mg/l in control group. There was a significant correlation between fetal urine (second puncture) and amniotic fluid in terms of cystatin-c level (p ¼ 0.030, r ¼ 0.717). Amniotic fluid cystatin-c level was significantly higher in fetuses with suspected infravesical obtsruction compared to control group (p < 0.0001). ESPU Programme 2009 S65