In-vitro procedures take place at the microscopic, 8-celled stage of development. What do you think the doctor implants--a human life, or an inanimate object?
Women who became pregnant this way would proudly show you their "products of conception." There are also donated frozen, microscopic embryos available for adoption--and many lucky children carried to term and born from them, are living healthy lives today. Now, that's the miracle of life in all its glory!
BTW, an infant, toddler, pre-schooler or adolescent is NOT an adult...so what's your point?