Incarceration of the gravid uterus(IGU) is a rare obstetric disorder.With the pregnancy weeks increasing

the gravid uterus transforms from a pelvic organ to an abdominal organ. In most cases

the retroverted uterus spontaneously corrects itself as the fundus rising out of the pelvis forward to its normal anatomical position between 12-14 weeks of gestation.[1] On rare occasions

the uterus remains in a retroverted position as it enlarges

becoming trapped in the pelvis between the sacral promontory and the symphysis pubis（the Douglas pouch or the uterovesical pouch）

[2]this is called incarceration of the gravid uterus. If it is not treated timely

it will lead to severe complications such as premature rupture of membrane

miscarriage or even the rupture of uterus

bladder and renal failure. Therefore

early diagnosis is the key to reducing complications .