Prosecutors are investigating whether Mr Berlusconi paid for sex with the then 17-year-old girl, Karima El Mahroug
The dancer was just 17 when the then prime minister allegedly paid to have sex with her last year, a crime punishable by up to three years in prison.
If convicted, the 75-year-old Mr Berlusconi also faces up to 12 years in prison for abuse of power after he allegedly put pressure on the police to have Miss El Mahroug, now 19, released from custody in an unrelated case.
Prosecutors allege that Mr Berlusconi paid for sex with Miss El Mahroug several times between February and May 2010. At the trial, which is ongoing, a police officer earlier this month testified that Miss El Mahroug was a prostitute.
Mr Berlusconi has denied all charges and claims he only gave Miss El Mahroug some money to help her out of a tight financial spot and intervened in her arrest because he thought she was the niece of then Egyptian president Hosni Mubarak.
The trial began earlier this year when Berlusconi was still in power but has been delayed for months by a number of motions put forward by his defence lawyers, as well as the slow-moving Italian judicial system.
The reports said baby and mother are fine, and the father, 42-year-old Luca Risso, who owned two discotheques in Genoa in northern Italy where Miss El Mahroug worked, said his "happiness is impossible to describe."