Hi OP. Depends on the child.
I've was self employed for DS1 and DD's entire life (DS is 18 now) and I managed by working in evenings, catching up where I could, and then once they started school, had more time.
However, DS2, different story, you cannot just cannot get anything done. He had a terrible time as a baby, no sleep, colic, issues with digestion when weaning, worst teething ever seen, frightened of everything, constant need to be near/hold etc etc.
So, in other words, if DS2 had been DS1, my business wouldn't have survived.
It will also depend on the work, and if you can squeeze it in during the day or resolve to working evenings. At one point, I did work from 8pm (DS bedtime) to 3am pretty much every night for 3 years.
I wouldn't recommend it, but sometimes, needs must. I was single.