During early pregnancy, the uterus is normally tilted in a forward position before rising up out of the pelvis, at approximately 12 weeks, into a relatively straight position in the abdomen. A retroverted gravid uterus occurs when the uterus is tilted backward. This is not uncommon, and the condition usually resolves itself at the 12-week point. Special concerns can arise, however, in the rare instance that the situation is not resolved, resulting in a condition called incarcerated uterus.
Incarcerated uterus can occur due to a number of factors or preexisting conditions. Previous multiple pregnancies, pelvic tumors, and fibroids can all be factors. Prior conditions such as endometriosis or pelvic infections can result in adhesions, which prevent the uterus from properly repositioning. Finally, anatomical abnormalities that may otherwise be clinically insignificant can play a role.
Symptoms of a retroverted gravid uterus can often be quite general and associated with a normal pregnancy. This can include lower back pain, pelvic discomfort, and rectal pressure, including a strong desire to pass stool while suffering progressive constipation. Urinary difficulties are the most common complaint, including the increased urgency to urinate but the inability to do so, eventually resulting in cystitis. This generally raises a red flag if the woman is only three to four months pregnant.
During examination, incarcerated gravid uterus can be identified by a distended bladder. Upon palpation of the abdomen, the displacement of the cervix and size of the uterus can also be felt. The condition is usually confirmed by the use of ultrasound and magnetic resonance imaging, which can more clearly display the position of the fetus.
If left untreated, a retroverted gravid uterus that has resulted in incarceration can have very serious complications. These can include thinning of the anterior uterine wall, which may subsequently rupture during labor. Thinning may also occur in the fetal membranes, which are also vulnerable to tearing. Bladder rupture, induction of preterm labor, and spontaneous abortion are also serious complications.
Treatment for this condition initially involves the insertion of a catheter to drain the bladder and reduce compression. The next step is to try and reposition the retroverted gravid uterus. This is often accomplished through physical manipulation by an obstetrician. Although usually performed while the woman is awake and assisting the maneuver by pelvic rocking, if the uterus proves to be very immobile, doctors use a general anesthesia and push the uterus into the proper position.