Postpartum haemorrhage is historically and globally the leading cause of maternal death [1]. The most dangerous time for a woman during the birth process is after her baby is born, around the time the placenta is birthed. While the mother and baby meet face to face, and the family greets their new member, there is a lot of important work going on behind the scenes (inside the woman).

This is an overview of what happens to ensure the placenta is born and the blood vessels feeding the placenta stop bleeding. I cover the physiology of childbirth in-depth in my book Reclaiming Childbirth, my online course Childbirth Physiology and my Early Integration Phase Lesson Package. The following is an overview:

At the end of pregnancy, the structure and biochemistry of the placenta changes. Recently, there has been discussion about how these changes may facilitate the separation of the placenta from the uterus after birth. This would make sense because pre-term and early term births are more likely to have problems with the separation of the placenta from the uterine wall.

I have written more about this in another post.

Birth does not happen in distinct stages and the birth of the placenta is part of a complex process that begins before the baby is born.

Oxytocin makes the uterus contract. Oxytocin is released by the posterior pituitary gland (in the brain) during labour to regulate contractions. It is one of the key birthing/bonding hormones. As the birth of the baby becomes imminent, high levels of oxytocin are circulating in the mother's bloodstream.

This creates strong uterine contractions which move the baby through the vagina, and prepare the mother and baby for post-birth bonding behaviours.

The bottom line is that the birth of the placenta and haemostasis (prevention of excessive bleeding) depend on effective uterine contraction. Ineffective uterine contraction is the leading cause of postpartum haemorrhage (PPH). Other causes are perineal/cervical damage or, even more rarely, clotting disorders.

There are two causes of ineffective uterine contraction after birth:

• Hormonal: Inadequate circulating oxytocin...

Continue reading this article on Dr. Rachel Reed's website here.