There is nothing illogical about abortion.
It's not unusual for animals to terminate their young AFTER birth if the situation demands; to reject their offspring, so is what we're doing so very different?
We have a global problem with the ever increasing size of the population and since it's evident that we can't fight the cause of unwanted pregnancies, then we have suffer the consequences.
It may sound brutal, but since we can't prevent people having sex, we can't prevent all unwanted pregnancies either.
Legalising abortion was a smart move to prevent back street abortionists not only terminating the foetus, but in some cases, the mother too.
Unless you can stop people having sex--and I think you'd have more luck sweeping air into a heap or herding cats, you will always have a need for termination.