Why are some medicinal interventions ok, some not?

[puzzleannie]

But isn’t the inability to fertilize and procreate a flaw too?
I like the explanation of the vaccines and lasik.

any medical procedure that corrects the disorder that is preventing fertilization, implantation, sexual function etc. is permissible and desireable as long as it does so in a completely natural way, and does not involve some distortion or perversion of the natural order and natural ends of marriage in so doing. So a surgery to unblock a fallopian tube or medication to stimulate ovulation would be permissible, but in vitro fertilization or artificial insemnation would be immoral because the circumvent the natural expression of sex in marriage for procreation and unity.

 

[preferanonymous]

any medical procedure that corrects the disorder that is preventing fertilization, implantation, sexual function etc. is permissible and desireable as long as it does so in a completely natural way, and does not involve some distortion or perversion of the natural order and natural ends of marriage in so doing. So a surgery to unblock a fallopian tube or medication to stimulate ovulation would be permissible, but in vitro fertilization or artificial insemnation would be immoral because the circumvent the natural expression of sex in marriage for procreation and unity.

Suppose a married couple had sex and the genetic material was taken from their sexual act and then in vitro fertilization was conducted by a doctor. Would this be circumventing the natural expression of sex?