It's important to note that "nwa" is a general term for child and can be used for infants, toddlers, and even older children.
If you want to be more specific about a baby, you can add a qualifier to "nwa" such as:
* Nwa ọhụrụ: newborn baby
* Nwa nta: small child (could be used for a baby)
Let me know if you have any other questions about Igbo!