Etiology, Mechanical.—
Retention of placenta—partial, total or solitary cotyledons.
Inversion of the uterus.
Placenta succenturiata.
Inflammation of decidua serotina.
Conduct of third stage, i.e., wait until placenta separates.
Etiology, Systemic, Hæmophilia.—
Kind of hæmorrhage.
Hæmorrhage before expulsion of placenta due to laceration of the soft parts, or
Partial release of placenta and failure of uterus to contract, or