‘The child was born about an hour before I came, and the midwife in attempting to bring away the placenta, had inverted the uterus; for upon examination, I found the whole body of the uterus with the placenta, adhering to the fundus, hanging out beyond the labia; there was a great profusion of blood, and the woman was dead before I came … This case should be a caution to all practitioners how they attempt to bring away the placenta, and not to pull the string too rudely, lest they invert and draw out the uterus, by which the woman dies a martyr to their temerity and ignorance, as was too plainly the case in the precedent observation’.
William Giffard
Cases in Midwifry. London: Motte, 1734, p421–422
Types
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Incomplete inversion occurs when the fundus of the uterus has turned inside-out, rather like the toe of a sock, but the inverted fundus has not descended through the cervix.
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Complete inversion occurs when the inverted fundus has passed completely through the cervix to lie within the vagina or, less often, outside the introitus.
Uterine inversion is sometimes described in degrees:
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1st degree = incomplete inversion
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2nd degree = complete inversion in the vagina
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3rd degree = complete inversion outside the introitus ( Fig 22-1 ).
FIGURE 22-1
Types of uterine inversion: (a) incomplete (1st degree), (b) complete (2nd degree), (c) complete (3rd degree).
‘A contracted uterus can be no more inverted than a stiff jackboot, but when it is soft and relaxed you may invert it’.
William Hunter
In: Andrews H R. William Hunter and his work in midwifery. BMJ 1915; 1:277–282
Causes
For the uterus to be inverted it must be relaxed and this, along with fundal insertion of the placenta, is an important predisposing condition. Additional factors are as follows:
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Mismanagement of the third stage of labour involving fundal pressure and/or cord traction before placental separation and while the uterus is still relaxed. This can be implicated in the majority of cases, despite the manifest surprise of the accoucheur. When reviewing a series of cases of acute uterine inversion to establish the causes Munro Kerr (1908) wrote:
‘In examining them it is very evident that in the majority of cases the occurrence has followed pressure from above or traction from below … In looking over the series I was not a little surprised at the large proportion of cases in which traction on the cord was the cause’.
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Abnormally short umbilical cord, or functionally shortened by being wrapped around the fetal body, can, in theory, cause the fundus of the uterus to be pulled inside-out by traction on the cord as the fetus delivers. This is extremely rare but plausible cases have been described.
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Sudden rise in intra-abdominal pressure due to maternal coughing or vomiting. This may occur in a vulnerable situation with the uterus relaxed and fundal insertion of the placenta followed by sudden and strong propulsion on the uterine fundus caused by the acute rise in intra-abdominal pressure.
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Morbid adherence of a fundally implanted placenta.
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Manual removal of the placenta. When separating a retained placenta from the uterine wall a portion may remain attached and as the placenta is withdrawn so too is the fundus of the uterus. This can occur with those who routinely and misguidedly undertake manual removal of the placenta at the time of caesarean section before the uterus has contracted.
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Connective tissue disorders, such as Marfan’s syndrome, can predispose to acute uterine inversion.
Clinical Presentation
The diagnosis may be obvious and dramatic with a large boggy mass appearing at the introitus, with or without the placenta attached. While this is the most dramatic presentation it is also the least common. Other signs and symptoms are as follows:
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Severe and sustained hypogastric pain in the third stage of labour.
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Shock that is initially out of proportion with apparent blood loss, due to the infundibulo-pelvic and round ligaments, ovaries and associated nerves being pulled into the crater of the inversion, which provides a strong vaso-vagal stimulus. Thus, the woman often becomes pallid and sweaty, with bradycardia, profound hypotension and even, on rare occasions, cardiac arrest. Within a short time, in the majority of cases, there is also marked haemorrhage and hypovolaemic shock.
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With complete inversion the uterus is not palpable per abdomen and the inverted fundus is either obvious at the introitus or on vaginal examination. In cases of incomplete uterine inversion, however, the fundus of the uterus may appear to be normal and only in thin women is it possible to feel the fundal dimple of the partial inversion.
‘Much of your success will depend upon your promptidude: the uterus should be returned quickly; but if there be much delay or violence, it may become impossible to do so’.
Edward W. Murphy
London Medical Gazette 1849; 8:751
Management
For acute uterine inversion to occur the myometrium and cervix must be relaxed. If the diagnosis is made immediately after it occurs, then that same degree of relaxation may allow immediate uterine replacement. Thus, if one is on the spot when the inversion happens, try immediate manual replacement. However, usually within 1–2 minutes the cervix and lower uterine segment clamp down and, along with increasing congestion, oedema and contraction of the inverted uterine fundus, this makes manual replacement without anaesthesia difficult, painful and usually impossible. If one attempt at immediate manual replacement of the uterus fails, move to the following sequence:
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Summon assistance (anaesthesia, nursing, obstetrician).
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Although the initial shock in these cases is usually of the neurogenic type, it is wise to be prepared for the haemorrhage and hypovolaemia that will follow in most cases. Therefore, establish two wide-bore intravenous cannulae, rapidly run in 1–2 L of crystalloid, take blood for cross match of 4 units, and place a Foley catheter in the bladder.
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If pain is a dominant symptom, small doses of intravenous morphine may be given.
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Anaesthesia should be administered depending on the facilities and appraisal by the anaesthetist. If an epidural anaesthetic is already in place this may provide adequate analgesia. In those rare cases in which the patient is stable, not bleeding, and with normal vital signs some anaesthetists may give a spinal anaesthetic. In most patients, however, cardiovascular instability and shock make regional anaesthesia inappropriate. Thus, general anaesthesia is usually chosen, using one of the fluorinated hydrocarbons (sevoflurane or isoflurane) to aid uterine relaxation. In the past halothane was used effectively for this purpose, but it has been replaced because of its association with rare cases of myocardial irritability/arrhythmia and hepatotoxicity.
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If general anaesthesia does not produce adequate uterine relaxation, or if a regional anaesthetic has been used, tocolysis will be necessary. The available drugs and technique are outlined in Chapter 28 .
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Manual replacement of the uterus should be undertaken once anaesthesia and tocolysis have been established. If the placenta is still attached to the fundus do not remove it, as this will increase the blood loss. If the placenta is partially attached to the fundus it should be peeled off.
The uterine fundus, with or without the attached placenta, is cupped in the palm of the hand, the fingers and thumb of which are extended to feel the utero-cervical junction ( Fig 22-2 ). The whole uterus is lifted up towards and beyond the umbilicus. Additional pressure is exerted with the fingertips to systematically and sequentially push and squeeze the uterine wall back through the cervix. This pressure may have to be sustained for 3–5 minutes to achieve complete replacement. Once the fundus has been replaced, keep the hand in the uterus while a rapid infusion of oxytocin is given to contract the uterus. When the uterus is felt to contract the hand is slowly withdrawn.
