What's the purpose of AN 2.61? What could be the purpose of the Buddha teaching AN 2.61 below? Why is this relevant? How is this useful?

AN 2.61 states:


  “Mendicants, females die without getting enough of two things.
  “Dvinnaṃ dhammānaṃ, bhikkhave, atitto appaṭivāno mātugāmo kālaṃ
  karoti.
  
  What two?
  Katamesaṃ dvinnaṃ?
  
  Sexual intercourse and giving birth.
  Methunasamāpattiyā ca vijāyanassa ca.
  
  Females die without getting enough of these two things.”
  Imesaṃ kho, bhikkhave, dvinnaṃ dhammānaṃ atitto appaṭivāno mātugāmo kālaṃ
  karotī”ti.
I suppose "to die without getting enough" is a colloquial expression for being insatiable, indefatigable.

This is an emphatic way of saying that women have a strong instinctual desire to bear children. If you polled a big enough sample of women I suspect majority would say they like to have children, enjoy having children, and many would say they'd want to have more then one child if allowed by the living circumstances.

The point of this in context of Buddha's teaching is that samsara has built-in mechanisms for self-continuation. Natural phenomena have innate tendency to proliferate, to continue, to support their kin, to procreate. 

Left unchecked, the stream of samsara rolls forward endlessly regenerating ignorance, confusion, desire, suffering, and desire to escape suffering. It is the ignorant pursuit of this desire is what supports the stream's momentum to roll on and on.