**11. Spontaneous hemoperitoneum in pregnancy and endometriosis**

Spontaneous hemoperitoneum in pregnancy is an uncommon yet dramatic cause of hemoperitoneum, associated with high perinatal mortality (31%) and 44% of these deaths attributable to maternal shock. No maternal deaths have been reported in the last 20 years. The condition is most common during the third trimester of pregnancy. Endometriosis is considered a major risk factor (Brosens *et al.*, 2009).

The cause of this condition is not fully clarified. Inoue *et al.* (1992) have suggested two possible explanations for the involvement of endometriosis: (i) chronic inflammation due to endometriosis may make utero-ovarian vessels more friable; (ii) the resultants adhesions may give further tension to these vessels when the uterus is enlarged during pregnancy. Invasiveness of severe endometriosis has been suggested as a reason for this entity, but Brosens *et al.* (2009) found no apparent correlation between spontaneous hemoperitoneum in pregnancy and stage of endometriosis.

The typical presentation of spontaneous utero-ovarian vessel rupture consists of a sudden onset of abdominal pain without vaginal bleeding, associated with signs of acute abdomen and hypovolemia. Fetal distress is an uncommon finding unless there is severe hemodynamic instability. Abdominal ultrasound examination does not reveal signs of placental abruption and fail to diagnose intraperitoneal bleeding as cause of acute pain. Transvaginal ultrasound and computerized tomography scans sometimes indicate the presence of intraperitoneal free fluid, but in most cases the diagnosis is only established at laparotomy (Brosens *et al.*, 2009). Preoperatively other potential diagnoses are placental abruption, uterine rupture, HELLP syndrome, abdominal pregnancy or rupture of the liver or spleen (Grunewald & Jördens, 2010).

At laparotomy, a substantial amount of hemoperitoneum is found (range: 500 to 4000 mL). The bleeding is not arterial but arise from superficial veins or varicosities on the posterior surface of the uterus or parametria. Treatment of bleeding is variable: thermal coagulation, hemostatic sutures or clips, or hysterectomy after caesarean section (Brossens 2009).

Since endometriosis may cause infertility, and assisted reproduction technology is increasingly used to enable patients to conceive, it is likely that there will be more cases with unprovoked hemoperitoneum in the near future (Grunewald & Jördens, 2010).
