Urinary function changes during pregnancy assessed by frequency volume charts in a prospective longitudinal study.

To prospectively evaluate urinary conditions and function in pregnant women by analyzing Frequency-Volume Chart data collected from early through late pregnancy. Pregnant women who visited the research facility and provided informed consent between June 2021 and May 2023 were enrolled. Participants were asked to complete a three-day Frequency-Volume Chart at three time points: early pregnancy (14-16 weeks gestation), mid-pregnancy (25-27 weeks gestation), and late pregnancy (34-36 weeks gestation). A total of 24 participants provided complete Frequency-Volume Chart data. An increase in urine volume correlating with weight gain during late pregnancy was observed. Additionally, both the voided volume and urinary frequency were significantly impacted as pregnancy advanced. Notably, the fetal position influenced maternal urinary conditions: fetuses in the "Right Occiput Position" were associated with statistically significant increases in maximum 24-hour voided volume, maximum nocturnal voided volume, and average nocturnal voided volume (p < 0.05). Furthermore, maximum 24-hour and nocturnal voided volume were significantly higher (p < 0.05) in pregnant women who used pelvic support devices. Our analysis indicates that as pregnancy advances, there is a significant increase in 24-hour urine volume accompanied by a decrease in voided volume. Additionally, both fetal position within the uterus and the use of pelvic support devices were found to significantly affect voided volume.