Uterine inversion occurs when the top of the uterus collapses into the inner cavity, turning the organ inside out. This rare obstetric emergency usually happens during the third stage of labor. While the exact trigger is often a combination of factors, pulling hard on the umbilical cord before the placenta has detached is a frequent culprit. A relaxed, atonic myometrium also plays a major role, as the uterine muscle lacks the tone to stay firmly contracted. Other known risk factors include rapid labor, short umbilical cords, and fundal pressure applied during delivery.
Midwives classify uterine inversion based on how far the fundus has descended down the reproductive tract.
The hallmark sign of a uterine inversion is sudden, severe postpartum hemorrhage accompanied by excruciating lower abdominal or pelvic pain. However, the most dangerous feature is profound neurogenic shock. Because the pelvic nerves and the peritoneum are stretched and pulled tight by the inverted organ, the patient often drops into a state of shock that is out of proportion to the amount of visible blood loss. Midwives must never rely solely on blood volume estimates; a pale, pulseless patient with a missing fundus on abdominal palpation demands immediate action.
Managing uterine inversion requires simultaneous resuscitation and replacement of the organ. Call for emergency backup immediately. Secure two large-bore intravenous lines and start rapid infusions of normal saline or Ringer's lactate. Stop any uterotonic drugs like oxytocin right away, because an actively contracting uterus makes manual replacement impossible. Gather the multidisciplinary team, prepare for blood transfusion, and keep the patient flat or in a slight Trendelenburg position to support cerebral perfusion.
The Johnson maneuver is the frontline manual technique used to push the inverted uterus back into place. The midwife places a gloved hand into the vagina, cups the fundus in the palm of the fingers, and lifts the entire uterus up into the pelvic and abdominal cavity toward the umbilicus. This action stretches the broad ligaments, which pulls the cervical ring open and allows the fundus to pop back to its normal shape. The hand should remain inside the uterine cavity, holding the fundus in place until the myometrium regains tone after administering uterotonics.
If manual replacement fails, surgical intervention becomes necessary without delay. Hydrostatic pressure using warm sterile saline infused via a vacuum cup can sometimes push the fundus back. When non-surgical methods fail, anesthesiology relaxes the uterus using agents like halogenated general anesthetics or nitroglycerin, allowing for surgical correction through either a vaginal approach like the Huntington or O'Sullivan procedure, or an abdominal approach via laparotomy such as the Haultain procedure. Post-reduction care involves continuous monitoring of vital signs, maintaining a uterotonic infusion to prevent recurrence, and administering broad-spectrum prophylactic antibiotics due to the high risk of infection.