OBSTETRIC HAEMORRHAGE

Hemorrhage is a common cause of maternal mortality.

It is the underlying cause in at least 25% of maternal deaths in the developing world.

In pregnancy there are physiologic adaptations in preparation for blood loss:

Blood volume increase (1000-2000mls) and increased red blood cell mass.
Hypercoagulable state (increased clotting factors,
Involution of uterus following delivery has a ‘tourniquet effect” on the spiral arteries of the gravid uterus.

Blood loss can occur rapidly because gravid uterine bleeding in pregnant women after delivery. blood flow at term is 600-900ml/minute, and when there uterine atony occurs, more than one unit of blood is lost every minute. including fibrinogen).

Resuscitation may be inadequate during post partum hemorrhage because:

Precise measurement of blood loss during cesarean section is almost impossible because of difficulties quantifying amniotic fluid.
There may be no change in the maternal systolic blood pressure until more than 25% of the bloodvolume is lost in pregnancy.

Pregnancy causes increased susceptibility to disseminated intravascular coagulation (DIC).

Uterine atony is the most common cause of significant

High risk situations are:

Over-stretched uterus: As seen in multiple gestation, macrosomia, polyhydramnios.
Tired uterus: As seen in high parity, prolonged labor, prolonged oxytocin use.
Sick uterus as seen in chorioamnionitis

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