Pre-natal cataloguing introduced by Dr. Ranganathan which include (1) Pre-natal cataloguing (2) Pre-natal Classification.
This work undertaken by National Central Library for each book before its release by the publisher. The national library prepared master stencil of catalogue card for each book before its release and provide call number, catalogue entry for each book, class number that can be printed on back of the title page and catalogue card that can be printed even when the book is release this is called pre-natal cataloging.
Source : Library and information science : analytical /evaluation questions and essay writing, published by Atlantic publisher & distributors pvt ltd., New Delhi
"Natal" is an adjective in English language which Means Birth. So "pre-natal" means before Birth. Pre-natal cataloguing generally refers to the books where catalogue (viz-bibliographic data according to AACR format) is already printed in book. so directly get the Catalogue from book.