What are the cases in which pregnancy is considered legally impossible between a husband and wife, despite the occurrence of pregnancy?

Protecting the honor and dignity of Muslims is an Islamic imperative. Islamic law forbids hurting feelings and spreading indecency, and it absolutely prohibits slander (Qadhf), making it a major sin. It obligates eighty lashes upon the slanderer, disqualifies his testimony, and rules him to be an evildoer (fasiq), accursed, and deserving of severe punishment, unless he provides irrefutable proof. Every child or pregnancy brought forth by the wife is legally attributed to her husband. Whoever denies this attribution is a slanderer, except in cases where it is impossible for the pregnancy or child to be from him, such as if the husband is a minor who has not reached ten years of age, or if he is married under circumstances where intercourse is impossible, or if she gives birth to a child in less than six months from his intercourse with her, or if she gives birth after six months from the end of her waiting period (iddah). However, if the husband is certain of his wife's adultery, he may deny the paternity of what she has given birth to through the process of Lian (oath of condemnation).