For nationality, most common law is that your baby "can" claim citizenship of the country where the airline you are flying in is registered.
example, if you're Singaporean and flying in Lufthansa airline, which is a german airline, your baby can claim a Germain citizenship.
But it all depends because many countries don't follow this rule.
And with facilities to delivery a baby, most of the international airliners today have facilities and trained hostesses to help in delivering a baby in-flight
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