Posterior sacculation of the uterus in a patient presenting with flank pain at 29 weeks of gestation.

BACKGROUND: Uterine sacculation is a rare complication of pregnancy and may cause substantial peripartal morbidity.

CASE: A possible diagnosis of posterior uterine sacculation was raised when a 34-year-old Gravida 1 Para 1 presented with bilateral flank pain at 29 weeks. Sonographic and magnetic resonance imaging findings confirmed the diagnosis and demonstrated bilateral dilated renal pelvises. Bilateral nephrostomas were placed, offering the patient considerable relief. A healthy female newborn was delivered by cesarean at 34 1/7 weeks. Operative findings confirmed the posterior sacculation of the uterus.

CONCLUSION: Early diagnosis of sacculation of the uterus is necessary to limit maternal and fetal morbidity and mortality. For a detailed evaluation of the pelvic anatomy, we recommend the use of magnetic resonance imaging in the third trimester.