in vitro fertilization

UK: /ɪnˌviːtrəʊˌfɜː^rtɪlaɪˈzeɪʃ^ən/

WordReference Random House Unabridged Dictionary of American English © 2025

in vi′tro fertiliza′tion, 

1. Medicine, Developmental Biology, Surgery a specialized technique by which an ovum, esp. a human one, is fertilized by sperm outside the body, with the resulting embryo later implanted in the uterus for gestation.

• 1970–75

Collins Concise English Dictionary © HarperCollins Publishers::

in vitro fertilization noun

1. a technique enabling some women who are unable to conceive to bear children. Egg cells removed from a woman's ovary are fertilized by sperm in vitro; some of the resulting fertilized egg cells are incubated until the blastocyst stage, which are then implanted into her uterus
   Abbreviation: IVF