Sheehan's syndrome is pan (all) hypo (low) pituitarianism.  It refers
to this rare problem when it occurs in the postpartum period, probably
secondary to a prolonged period of low blood pressure secondary to
blood loss, but could, in theory, occur with anything that lowers
blood pressure, such as epidural anaesthesia.  With good obstetric
practice as should be expected in this day and age, at least in
theory, Sheehan's syndrome should not occur.

Because all pituitary secretions are low, the mother does not produce
prolactin and possibly oxytocin, though there is generally more effect
on the anterior pituitary.  These women never get any milk supply, or
extremely little.  They also can be hypoglycemic from low steroid
production (from poor production of ACTH--acetocorticotropic hormone),
and growth hormone production and have fatigue, weight loss and a
whole host of problems.

It is a rare problem.  Pituitary insufficiency can occur for other
reasons, but if a woman has it before getting pregnant, she is not
going to get pregnant, usually.

Jack Newman, MD, FRCPC