This says more than I can,,,
Source plus other comments from others:
https://www.quora.com/Can-parasites-be-in-the-same-species-of-the-host?top_ans=117159916
Although there are some species that are parasitic on their own kind, like deep sea male Angler fish which attach themselves and fuse to the female as a solution to the difficulty of finding a mate in the deep,,,
Calling an fetus a parasite is kind of missing the point, as reproduction is the purpose of mature breeding age females.
That we're so detached from basic biological functions (like the silly formula shortage crisis when women carry around two producers of free natural non-GMO baby formula right on their chests) and have reduced them to repurposed cultural accoutrements doesn't change what various organs are and their actual functions.
Sure, we live affluent lives with ample leisure time in a way overpopulated planet, so reproduction is not necessarily a priority, but pair bonding and mating as one thing and the offspring it may produce if they succeed as an invasive hindrance really needs some educational introduction to the purposes of, pehaps via some anthroplogical texts, literature, or even Soap Operas if people forgot what the why, how, and what aftermath of the birds and the bees thingy.
Granted, marriage has made having children a secondary consideration, but that only serves to make its original secondary purpose into its primary, and that is economic.
The leading cause of divorce (in trad marriages) is the husband losing his job, and marriagesdepend on him being the chief breadwinner, even in today's world with both spouses often working. That would pretty much in effect make her something of a parasite, some rather miffed ex hubbies might say. Does that provide him the option to dispense of her in a permanent way? Mind you, there was a time not too long ago that women were also 'scientifically' gauged to be mindless brutes, given to implulses and hystrionics, and supposedly devoid of intellect. The same was said of slaves, and served as not just the justification of it, but for the right to abuse them, as well as wives.
Life is parasitism, life is theft, life is murder. Some people see that as reason to kill what they will. Does it mean they should?
On the other hand, does it mean they shouldn't? ;p