I always love taking on the “respecting individual autonomy” argument, since the fetus is both integral to the mother and simultaneously autonomous. It’s also useful to take them on with their “fetus = tumor” analogies:
The fetus is integral to the mother since he or she (that’ll drive ‘em crazy!) is not an abnormal growth (such as a tumor). Instead, he or she is part of the normal female biological process and integral to it. Thereby, killing the fetus breaks the autonomy of the mother’s designed and normal (as opposed to a tumor) body processes.
The fetus is autonomous, as he or she is entirely human in both immediate (contains the full human DNA) and potential form (unlike a tumor, which is just tumor).
And not content with murder of the unborn, once born, the Left seeks to make feelings determintive of gender!