**3. Most common causes of maternal collapse**

#### **3.1 Hemorrhage**

Worldwide, Hemorrhage is still the leading cause of maternal mortality and it is the leading cause of maternal collapse on the delivery unit. The estimated incidence 3.7 per 1000 maternities. Predisposing factors are multiple pregnancy, high parity, placenta previa, uterine fibroids, and multiple previous caesarian sections, prolonged labour, maternal clotting disorders and preeclampsia. A high index of suspicion can be lifesaving. It is helpful to memorize the risk factors because hemorrhage can be concealed and pregnant women may lose a significant amount of blood without any hemodynamic disturbance. It is important to note that the blood loss is frequently underestimated and if hemodynamic changes become apparent, the mother has usually already lost third of her circulating blood volume.

#### **3.2 Thromboembolism**

A carful risk assessment for thrombotic complication should be performed in all pregnant women during the antenatal and postnatal periods. Multiple risk factors can make thromboprophylactic treatment necessary in pregnancy and postpartum for up to 6 weeks depending on risk assessment. Remember that deep venous thrombosis (DVT) of the pelvic venous system is often asymptomatic until pulmonary embolism develops.

### **3.3 Amniotic fluid embolism**

The incidence of AFE is estimated at 1.25–12.5 in 100,000 maternities. While this is an unpreventable event, the speed of diagnosis determines the outcome. Survival rates have improved to 80%; however neurological morbidity is recognized. There is no diagnostic test to determine AFE; therefore, the clinical picture should lead to a high index of suspicion. Clinical features include respiratory distress, followed by cardiovascular collapse with hemorrhage due to coagulopathy within 30 minutes of delivery. AFE can also occur antepartum during labor and become manifest as fetal collapse of unknown origin that precedes maternal collapse. In all cases there is absence of any other significant medical condition or other explanation for the rapid deterioration.

### **3.4 Sepsis**

Morbidity and mortality from pregnancy –related sepsis is common and has not significantly declined in recent years. Sepsis must be treated promptly as a medical emergency and appropriately managed with a 1 hour bundle to improve outcomes [3]. Obstetric risk factors include prolonged rupture of membranes, cervical cerculage, retained placenta and operative trauma. Patient related risk factors include obesity, anemia, diabetes mellitus, sickle cell disease and group B streptococcus infection. Adequate antibiotic prophylaxis for patients at risk is crucial. Common clinical signs are temperature, tachycardia and altered mental state, ranging from anxiety to confusion. Special attention should be paid to changes in the respiratory rate as an early diagnostic sign of the physiological reaction to a developing metabolic acidosis due to sepsis.

### **3.5 Complication of labor analgesia**

Even in a correctly sited epidural catheter, a regular top up with local anesthetic drugs can cause maternal collapse due to hypotension; therefore regular blood pressure observations are required after each administration of local anesthetic.
