Antepartum uterine rupture in previous caesarean sections presenting as advanced extrauterine pregnancies: lessons learnt.

In present day obstetric practice, rupture of a previously scarred uterus should be uncommon. It occurs in <1% of previous caesarean sections and most cases occur during labour and have evidence of abnormal fetal heart rate patterns, vaginal bleeding and continuous abdominal pains. Clinicians are alert to these symptoms and signs, and therefore immediate action is taken to prevent further maternal morbidity and mortality. However, rupture of a previously scarred uterus may occur occasionally in the antepartum period. In such circumstances, the patients may be haemodynamically stable and present with loss of fetal movements and vague abdominal pains, and are treated expectantly for a period of time because an initial diagnosis of advanced extra-uterine pregnancy is made. We present a series of 7 cases, all of whom had one or more previous caesarean sections, were haemodynamically stable and were being managed expectantly, to illustrate the fact that ruptured uterus should be strongly considered in the differential diagnosis, even when the clinical signs and sonography are suggestive of an advanced extra-uterine pregnancy. The lessons in these cases fall into the following categories: 1. Ruptured uteri can occur in non-labouring women with previous lower segment caesarean sections. 2. Absence of signs of peritonism is possibly due to the fact that the pregnancy is extruded through the uterine rupture with the amniotic sac being intact and there is little or no bleeding into the abdominal cavity or vaginally. 3. Imaging techniques should focus on the size of the uterus, as an enlarged uterus in the background of an advanced extra-uterine pregnancy in a previously scarred uterus is highly suggestive of uterine rupture. Clinicians must strongly consider ruptured uteri in non labouring women with previous caesarean sections even when imaging modalities suggest an advanced extrauterine pregnancy. This will lead to earlier surgical treatment and appropriate information being provided to patients.