**4. Indications and risk factors**

In a systematic review and meta-analysis, the overall mean maternal age ranged from 26.2 to 37.9 years, the weighted mean gestational age was reported at 37.0 weeks of gestation, and the weighted mean parity was observed at 4.0 [6].

Uterine atony was reported as the principal indication for PH, but it has changed toward abnormal placentation. Indications for PH are summarized in **Table 2** [6].


#### **Table 1.**

*Possible reasons for observed variations in incidences of PH.*


**Table 2.**

*Indications for PH.*

An elective PH may be performed if abnormal placentation is diagnosed in the antepartum period. Occasionally pregnant women with stage IA2 and IB1 cervical carcinoma are candidates for an elective PH [11]. Severe postpartum infection unresponsive to medical therapy and placental site vessel subinvolution is other potential indications for elective PH [11–13]. Also, giving birth with cesarean section is associated with a fourfold risk compared to vaginal delivery [14].
