I agree with Dr. Johansson about term babies. For preterms, though, we've sent many babies home with a haematocrit as low as 26 when they have high reticulocyte count, are on iron supplementation AND have a good weight gain. These babies would have a very close follow-up (1 week after discharge the haematocrit and weight are checked) and parents would be well orientated about signs of severe anaemia.
I've seen colleagues discharging preterms when EVF is as low as 24, but that would be too much for me to be comfortable with the situation.