A 34-year-old multiparous woman was admitted at 7.2 weeks of gestation with acute urinary retention and a mass in the upper vaginal wall. She had adenomyosis (uterus size, 10.4 cm × 11.6 cm), and a 2-week history of increased urinary frequency and a sensation of incomplete bladder emptying. In the emergency room, 850 mL of urine was drained by urinary catheterization. Transvaginal (TV) ultrasound and MRI showed no specific findings except a retroverted gravid uterus with adenomyosis, and an elongated and anteriorly displaced cervix behind the pubic symphysis (; TV ultrasound, ; MRI). Nonetheless, uterine incarceration was clinically suspected. The change in uterine polarity was noted after manual reduction (), and a pessary was inserted to prevent recurrence (74 mm; Smiths Medical, Minneapolis, MN, USA). The pessary was removed at 15 weeks, and the patient delivered a healthy male baby weighing 3,100 g at 38 weeks. Ultrasound examination performed at 6 weeks after delivery showed a retroverted uterus with a slightly thickened wall, although it was thinner than expected ().
A 26-year-old woman followed the course approximately similar to the Case one. She experienced urinary retention requiring urethral catheterization, which drained 900 ml of clear urine, at 12 weeks of her first pregnancy. Transvaginal sonography also revealed a retroverted uterus. The same prophylactic measures were suggested to the patient. Until 14 weeks’ gestation, urinary retention requiring urethral catheterization recurred two times. At 16 weeks’ gestation, the gravid uterus was examined and no retroversion was observed anymore. She had no recurrence of urinary retention during the rest of this pregnancy. Two years later, she consulted our hospital again due to urinary retention at 11 weeks of her second pregnancy.