Dumb Blonde

A dumb blonde is about to have a baby, she asks the doctor if he can already see anything. 'Yes' he responds 'I can see the head, but it is black. Have you ever had sex with a black guy?'
'I did, once' the blonde replies.
'Once can be enough' the doctor says.
Next the doctor can see the upper body of the baby, but surprisingly it is yellow.
'Did you also have sex with an Asian guy?' the doctor asks.
'Yes, but only once'.
'Again, once can be enough' the doctor says.
After one final push the baby pops out, but the legs are all red.
'Let me guess', the doctor asks 'you had sex with an Indian (Native-American), but only once'. The girl nodded.
The doctor takes the baby and gives it a smack on the butt, as the baby starts crying the doctor tells the blonde 'Well, at least the baby is healthy'.
At the same time the blonde makes a huge sigh of relief 'Thank god, I was afraid it was going to bark!'