Uterine inversion

Uterine inversion is a potentially fatal childbirth complication with a maternal survival rate of about 85%. It occurs when the placenta fails to detach from the uterus as it exits, pulls on the inside surface, and turns the organ inside out. It is very rare.

Causes

Most common cause is mismanagement of 3rd stage of labor

• Fundal pressure
• Congenital weakness
• Excess cord traction during the 3rd stage of labor
• Precipitate delivery
• Uterine weakness
• short umbilical cord

It is more common in multiple gestation than in singleton pregnancies.

Incidence 1/2000 pregnancies

Types

• ONE: Complete. Visible outside the cervix.
• TWO: Incomplete. Visible only at the cervix.

Associations

• Placenta praevia
• Fundal Placental Implantation
• Use of Magnesium Sulphate
• Vigorous fundal pressure
• Repeated cord traction
• short umbilical cord

Presentation

Uterine inversion is often associated with significant Post-partum hemorrhage. Traditionally it was thought that it presented with haemodynamic shock "out of proportion" with blood loss, however blood loss has often been underestimated. The parasympathetic effect of traction on the uterine ligaments may cause bradycardia.

Management

Principles of management are to treat the shock and replace the uterus. The patient should be moved rapidly to the OR to facilitate anesthesia monitoring during this procedure. Usually this complication is only recognized after delivery of the placenta, wherein pitocin has already been started, which just exacerbates the problem. The uterus clamps down around the inversion making it very difficult to perform a replacement. This is a true obstetrical emergency, so extra doctors, nurses, anesthesiologists should be summoned to the room to assist. The pitocin should be turned off immediately. Giving tocolytics such as terbutaline or magnesium sulfate have a lower success rate. Halothane and Nitroglycerine (100mcg to 200 mcg intravenously) have a higher success rate.

Once you have achieved uterine relaxation, place your fist into the vagina. Find the biggest part of the inversion and push with your fist cephalad to replace the uterus. This takes firm steady force, so keep your fist in the vagina if you need to rest your hand. Then continue more force toward the fundus to replace the uterus. You can use your left hand on the outside of the abdomen to help you feel where the fundus should be replaced. This helps guide the angle of your fist in replacing the uterus. Once it is replaced, give the patient Misoprostol 1000 mcgs rectally to help with increasing uterine tone. Other medications such as Methergine and Hemabate can be used. If you have heavy bleeding, consider inserting a Bakri balloon into the uterine cavity to tamponade the bleeding.

These patients have usually sustained heavy blood loss, and should be monitored in the ICU postoperatively. If you have given nitroglycerine, they must have cardiac monitoring postoperatively.

Other personnel should be monitoring vital signs, ordering blood products, assisting the anesthesiologist, drawing labs, and stabilizing the patient. Remember that nitroglycerine can cause hypotension, which can be reversed with ephedrine.

If external replacement fails, a laparotomy may be required, in which the uterus is gently pulled the right way round using forceps.