Urinary Flow Pattern in Premature Boys at the 32th Gestational Week

• Published in: Journal of pediatric urology Vol. 5; p. S65
• Main Authors: Olsen, L. Henning, Grothe, Ingrid, Rawashdeh, Yazan F., Joergensen, Troels M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2009
• Subjects: Pediatrics; Urology
• ISSN: 1477-5131; 1873-4898
• DOI: 10.1016/j.jpurol.2009.02.108

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. 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). 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 = 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. 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.