Twelve-hour daytime observation of voiding pattern in newborns <4 weeks of age

To investigate the voiding pattern in <4-week-old newborns by 12-h daytime observation periods.

Twenty-one healthy 1- to 28-day-old newborns were included (10 full term, 11 preterm). The 12-h free voiding parameters, including voiding frequency (VF), voiding volume (VV), post-voiding residual volumes (PRV) and status at voiding (awake/sleep), were recorded at day 1, 4, 7, 14 and 28 after birth.

Voiding was recorded 778 times. VF increased in the full-term and preterm newborns between day 4 and 7, decreased in preterms between day 14 and 28, but remained higher than in the full terms. VV increased twice in full terms and once in preterms during 28 days and PRV fluctuated. In contrast, VV was higher in the full term than in the preterms at days 4, 7, 14 and 28. PRV was higher at days 4 and 28. Interrupted voiding was less frequent in the full term than in the preterms.

Voiding pattern in the preterms differed in many ways from that of the full-term newborns. Frequent interrupted and incomplete voiding pattern in the preterm newborns indicates a disrupted coordination of the detrusor-sphincter and a delayed maturation of the neural micturition centre.