On the Day you see it every nursing mother will be distracted from that [child] she was nursing, and every pregnant woman will abort her pregnancy, and you will see the people [appearing] intoxicated while they are not intoxicated; but the punishment of Allāh is severe.
Commentators differ on whether this Surah is Makkan or Madani. Ibn ` Abbas ؓ has expressed two views on different occasions. However, a majority of commentators believe that the Surah is a combination of both the Makkan and Madani verses, and Qurtubi prefers this view. He has also mentioned the other peculiarities of this Surah, namely that some of its verses were revealed at night and some during the day; some were revealed during travels and some when the Holy Prophet ﷺ was not traveling; some were revealed in Makkah and others at Madinah; some were revealed in the middle of battle and others in peace time. Some verses of this Surah are nasikh (verses of the Qur'an abrogating some other verses), and some are mansookh (verses of the Qur'an which have been abrogated by others); some are muhkam while others are mutashabih (مُتَشَابِہ). Indeed this Surah comprises all categories of revelations.
This is a literal description of some of the horrors of Doomsday, a day which will throw people into such a state of sheer horror that the mother will forget the baby at her breast and the pregnant woman will miscarry. The earthquakes occurring in our present world give only a slight foretaste of the events of Doomsday. The onset of the great earthquake of Doomsday will make man forget everything he had considered important and due to which he had forgotten Doomsday—so much so that on that Day he will forget even his most cherished possessions and his near and dear ones.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.