Seems like it's saying the unborn is a parasite, but an anti-abortion politician said it, so he's being lambasted for insulting the woman.
ADDED: It's worth noting that the politician, Virginia State Sen. Steve Martin, added in parentheses "some refer to them as mothers." Here's the whole sentence: "However, once a child does exist in your womb, I'm not going to assume a right to kill it just because the child's host (some refer to them as mothers) doesn't want it."
Let's not forget that abortion-rights advocates have also objected to the word "mother," most notably when Justice Kennedy used it in Gonzales v. Carhart (the 2007 case that upheld the federal ban on "partial birth" abortions). Here's what lawprof-blogger Jack Balkin wrote at the time:
In his discussion of informed choice and in his purple prose about the natural bonds of love between mothers and children — call it Kennedy's "mother and child reunion" speech — Justice Kennedy adopts some of the rhetoric of Operation Outcry — an anti-abortion group which has honed the new style of pro-life rhetoric. The basic goal of this new rhetoric is to undermine the notion that women exercise any kind of choice when they decide to have abortions. It seeks to turn the rhetoric of the pro-choice movement on its head. Women, the new rhetoric argues, don't really understand what they are doing when they decide to have abortions; as a result, they often regret having them later on....That Operation Outcry rhetoric parallels rhetoric one often hears from left-liberals — not on abortions, but on economic matters. See "What's the Matter With Kansas?" And remember when "If you like your health insurance, you can keep your health insurance" was exposed as a false promise and some Obamacare supporters got nuanced about the meaning of "like," so that it didn't mean what a person felt he liked, but what the government knew he really, deep down inside, liked.
[The idea] is that because of the kind of culture we live in, women who think they know what they are doing when they have abortions actually don't know. They only think they know at the time. Later on, they will come to regret it, and we can say that they weren't informed. And because we can't tell which women will come to regret the decision later on, the state needs to pass laws that discourage all women from having abortions.
I prefer the locutions that treat the woman as an autonomous individual with a fully human mind, capable of reflecting on the real or potential humanity of the contents of her womb. I think those who are anti-abortion should show respect for the woman's authority over her own body and concentrate on persuading her to love and protect the unborn entity.
But politicians like Martin wield power in legislatures, and as they say, to a hammer, every problem looks like a nail. When you are a lawmaker, every problem looks like it needs a law. The bad part of Martin's statement, to my eye, is "I'm not going to assume a right...." I think legislators should have tremendous respect for the liberty of the people. They should assume a right to be free of constraints. Presume against restrictions. That should be your starting point. Then ask why your solution justifies the limitation.
AND: Here's what Justice Harlan wrote in Poe v. Ullman. That was in 1961, before Griswold v. Connecticut, in which the majority of the Supreme Court saw the right of privacy that became the basis for abortion rights. Harlan was the conservative on the Warren Court, so he is expressing the libertarian position that might be persuasive to some conservatives today:
The best that can be said [about due process] is that, through the course of this Court's decisions, it has represented the balance which our Nation, built upon postulates of respect for the liberty of the individual, has struck between that liberty and the demands of organized society....
This "liberty" is not a series of isolated points pricked out in terms of the taking of property; the freedom of speech, press, and religion; the right to keep and bear arms; the freedom from unreasonable searches and seizures; and so on. It is a rational continuum which, broadly speaking, includes a freedom from all substantial arbitrary impositions and purposeless restraints....