Human rights are generally held to apply to 'people'.
The first article of the Universal Declaration of Human Rights states
That first sentence -"All human beings are born free and equal in dignity and rights." - could be taken as a definition of thsoe to whom the Declartation applies, and the word "born" would appear to be definitive withing it. One must be born to be a person. As abortion happens to the unborn, it would appear that it is not against the UN Declaration of Human Rights.
A general definition of 'person' usually includes something along the lines of "an individual human being". A foetus is not 'individual' many would argue, as it is a part of its living 'parent' until it is born.
Others suggest that the foetus becomes an 'individual' when the time comes in the pregnancy when it would be capable of independent existence were it to be separated from its 'parent' by some means - whether by medical procedure or very premature birth. Such people say that the foetus at that stage has become a person and deserves to be endowed with the rights due to a person.
There are, of course, other definitions of what constitutes 'human' or 'person' - and there may well be various national definitions of human rights in various countries.