Are there any evidence-based management protocols for uterine inversion – how could they be developed for such a rare, yet dangerous, complication?

As the incidence of uterine inversion is of the order of 1/20,000 cases¹ only a nationwide effort to report all relevant facets of every case, especially the sequence and outcome of each intervention, from second stage through to final resolution, could generate enough data.

The recent report, Axillary Traction: An effective method of resolving shoulder dystocia,² shows how, from the pooled experience of many operators, evidence-based management protocols can be developed.

I handled possibly 10 cases of uterine inversion over 30 years practising in Fiji. Of these, only one was detected when incomplete and replaced manually. One patient died. She died undiagnosed while the chartered relief flight was in the air. All others were successfully resolved using O’Sullivan’s hydrostatic method (OSH), so I never had occasion to consider using either of the invasive Haultain or Huntington procedures.

Although manual replacement is the obvious and effective management when the inversion is incomplete, I want to stress that the OSH method is effective, minimally invasive, requires no special apparatus, and can be performed, if required, in less-than-ideal situations. It never failed my patients, my colleagues, or me.

O’Sullivan’s Hydrostatic Reduction method

You will need to have 4–5 litres of warmed electrolyte fluid on hand, the bladder catheterised, and the patient sedated.

Sterile water is the wrong fluid.

Some of the infused fluid will enter the circulation via the uterine vessels as the hydrostatic pressure builds up. Isotonic fluid is required and why look beyond the normal saline ‘for IV infusion’, which can be run in through ordinary IV tubing sets? If blood-warming sets are not available, immerse the intact bags in bowls of hot water.

You will need patience.

It will take 3–5 litres to distend the vagina and build up the pressure to the point where the constriction ring relaxes enough to let the uterus ‘pop up’ in the manner of the fingers of a surgical glove, and becomes palpable above the pubis.

I used twin infusions, from a height of not more than 1 meter above the pelvis, with the fluid outlets as high as possible in the vaginal fornices.

Sealing off the vagina.

I found this could be done by either placing the whole hand inside the vagina; or, if the vagina and perineum were very lax, by inverting the labia and pressing hard against the whole introitus with both hands and surgical packs/pads. In one case, I inserted tight, but temporary, perineal sutures.

In the absence of personal experience, I cannot envisage a balloon that would adequately seal off the progestogen-stoked passage, traversed, within the hour, by the neonate! Seeing might be believing!

Anaesthesia is desirable.

But morphine, and local infiltration around the introitus, serve well. In any case, morphine is indicated, in small incremental doses, to mitigate the neurogenic shock which is commonly present.

Oxytocic administration should be suspended as soon as inversion is recognised, and restarted when it is corrected, at the same time as manual removal of the placenta (if required) is underway. The uterine cavity must be rechecked after the placenta is removed.

Manual replacement

If the inverting fundus can be identified before a constriction ring has formed, seize the moment.

Suspend oxytocic infusion, and push it back. Give the patient whatever analgesia is readily available; a judicious dose of morphine is helpful in preventing/treating neurogenic shock; separate and remove the placenta; restart oxytocics infusion.

Post-procedure

• Continue oxytocics infusion and bladder drainage for up to 12 hours, with frequent monitoring to confirm the uterus remains normally palpable per abdomen.
• If large volumes of electrolytes have been infused IV during resuscitation, the patient may have become hypervolaemic; especially if blood transfusion is required to correct anaemia. Consider giving a small dose of frusemide (no more than 10mg) to trigger diuresis, and preclude circulatory overload.

Note: I have dealt only with the specific treatment; resuscitation, analgesia, monitoring, preparation and use of blood products must of course proceed concomitantly. And an indwelling catheter to keep the bladder empty.

The PROMPT algorithm is an excellent general guide: Identify the problem, signal Code Red, resuscitate as needed, reverse the inversion ASAP, then separate the placenta; keep the bladder empty; monitor closely for at least 12 hours to ensure the uterus remains contracted and eumorphic.

Some notes on diagnosis of uterine inversion

This is easy enough when uterus, +/- placenta, is protruding from the introitus, but when the uterus lies within the vagina, it has been missed.

It will not be missed if a digital exploration of the birth canal is routinely made:

• whenever bleeding is excessive, whether the placenta is expelled or not; and/or
• when there is abnormal pain, and/or disproportionate shock; and/or
• you cannot feel a normally-firm fundus per abdomen.

If the placenta has been expelled, and the uterus is inverting, you will feel a firm, fibroid-like mass just inside the cervix, or in the vagina, and passing your finger around the upper vagina, you will confirm that it is emerging through the cervical os. The inverted uterus itself is firm, similar to a fibroid.

1. Witteveen T, van Stralen G, Zwart J, van Roosmalen J. Puerpural uterine inversion in the Netherlands; a nationwide cohort study. Acta Obstet Gynaecol Scand. 2013;92:334-7.
2. Ansell L, Ansell D, McAra-Cooper J. Axillary Traction: An effective method of resolving shoulder dystocia. ANZJOG. 2019;559:627-33.