Being a parent, there is very little worse to watch than bad things happening to children, or in this case a baby. Unfortunately, the nature of the show dictates that this is bound to happen from time to time.
Even worse is when it turns out the parents murdered him because they (wrongly) feared he had an incurable disease.
Such episodes really depress me, and though it was good, given the chance I'd not watch it again. Call me weak, but I just find it too difficult to watch.
The other two storylines were average, one of which (the man in the chair) was very underdeveloped, and almost thrown in as an afterthought.