I would say healthcare is not a commodity but a right (and a service provided by professionals) - As for medical ethics, I don't actually oppose doctors not performing abortions if there's someone else who is available to do it because I understand the different conceptions of life people have but treating children of same-sex couples does not violate your ethics in anyway - In fact, it is completely irrelevant who the parents are and what they do, what matters is that you have to treat someone - In this case you are basically saying "fuck you" to a kid because of what their parents did or do.
Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you