Look what I came across, this is what one medical author described pregnancy as:

"...a neoplastic, endoparasitic (i.e. neoparasitic) autoinfection of relatively high pathogenicity and low average virulence which is localized, self-limited, and nontransmissible; "

And we want to do this to ourselves why?

It's an article about whether or not pregnancy might be considered a disease. You can read the full thing here:

THE ILLNESS PARAMETERS OF PREGNANCY