Submitted by oncidiumfan on Thu, 2013/09/12 - 10:22.
If you're the father of a Nicaraguan child, apparently legit or not, you can register the birth and get the US citizenship, but probably will have to have a DNA test if the Embassy is suspicious.
http://www.travel.state.gov/law/citizenship/citizenship_5199.html is a further link to this:
"Birth Abroad Out-of-Wedlock to a U.S. Citizen Father – “New” Section 309(a)
A person born abroad out-of-wedlock to a U.S. citizen father may acquire U.S. citizenship under Section 301(g) of the INA, as made applicable by the “new” Section 309(a) of the INA provided: