Is the pregnancy of an unmarried woman considered evidence of Zina (adultery/fornication)?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Muslim jurists held different opinions on whether the pregnancy of an unmarried woman, who has no husband or master (as a slave-girl), is regarded as evidence of Zina, which entails the application of Hadd (i.e. corporal punishment prescribed for crime set by Sharee'ah) or not. The majority of Muslim scholars believed that a woman who is accused of extramarital pregnancy should not be subjected to the prescribed Hadd for Zina. This is based on the probability that the unlawful sexual intercourse took place by way of Shubhah (thinking that it is lawful while in reality it is unlawful) or coercion, i.e. rape. Meanwhile, prescribed corporal punishments are dismissed in case of uncertainty. The famous opinion of the Maaliki scholars suggests that the pregnancy of an unmarried woman is evidence of Zina, and they do not accept her claim of rape except if there is proof. This is supported by the fact that ‘Umar ibn Al-Khattaab was reported to have said:

Stoning is mentioned in the Book of Allaah. It is due to be applied on whoever commits adultery, man or woman, if he/she is Muhsan (currently or previously married). This is so if any of the following proofs are available: 1) the availability of clear proof, 2) pregnancy, 3) a confession. [Al-Bukhari and Muslim] 

This was said in the presence of some of the Companions and none disapproved of it.

The majority of jurists relied on the narration which relates that:

A pregnant, unmarried woman was brought to ‘Umar ibn Al-Khattab who asked her about that and she replied, "I am heavy-headed, and a man came and had sexual intercourse with me while I was deeply asleep. I did not wake up except after the man had finished (having intercourse with me)." ‘Umar ibn Al-Khattaab dismissed the (application of) Hadd in this incident. [Ibn Abi Shaybah, Sa‘eed ibn Mansoor, and Al-Bayhaqi]

The opinion of the majority of Muslim scholars is further supported by the story of the woman from Hamdan and ‘Ali's dictating her. A woman of the Hamdan tribe was brought before ‘Ali . She was pregnant.  ‘Ali said to her, "Maybe the man raped you." She said, "No."  Imaam ‘Ali said, interrogatively, "Possibly, you were fast asleep and the man did that while you were deeply asleep." She replied in the negative ... Imaam Az-Zayla‘i said:

"This Hadeeth has been reported via different chains of narration, one of them was narrated by Ahmad and Al-Bayhaqi. If these excuses were not acceptable for dismissing the Hadd, then ‘Ali would not have dictated them to the woman as he did." [Nasb Ar-Rayah]

Ibn Taymiyyah said:

"If a woman who has neither a husband nor a master (meaning that she is not a slave girl) got pregnant, the Hadd for Zina should be implemented unless she claims that this took place due to a Shubhah (having intercourse mistakenly believing it is lawful while in fact it is unlawful." [Al-Fataawa Al-Kubra]

Allaah Knows best.