Tell or Say, what reasons of not developing pregnancy, except for vnutr can be...

[Tatyana]

Tell or Say, what reasons of not developing pregnancy, except for internal infections can be? Why occurs or happens nesozrevanija placentas?

[child]

Doctors in such cases write, that the reasons are unknown. The nature simply. As well as early abortions - simply occur or happen any failures in conception - unsuccessfully - and the nature, an organism get rid of them