The South African recipient of the world's first penile transplant is to become a father, a surgeon who performed the operation has told the BBC.
His girlfriend has reported that she is about four months pregnant, and this showed that the "transplant worked", said Andre van der Merwe.
The 21-year-old recipient, whose identify is being protected, lost his penis in a botched circumcision.
The operation took place in December.
Surgeons at Stellenbosch University and Tygerberg Hospital performed a nine-hour operation to attach a donated penis.
Dr Van der Merwe said he was "very pleased" when he heard that the man's girlfriend was pregnant, and had not asked for a paternity test as there was no reason not to believe the couple.
"This is what we intended, that he should be able to stand up and be able to urinate and have intercourse, so it is a milestone for him," Dr Van der Merwe told the BBC.
He had not expected the man to be infertile, as he had an issue with his penis, not his testicles, the surgeon added.
Dr Van der Merwe said the surgical team is yet to review the success of the operation, and may then carry out further transplants.
The boy had been left with just 1cm of his original penis as a result of the botched circumcision. He was 18 and sexually active at the time.
When attaching the donated penis, the surgical team used some of the techniques that had been developed to perform the first face transplants in order to connect the tiny blood vessels and nerves.
There have been attempts at penis transplants before, including one in China.
Accounts suggested the operation went well, but the penis was later rejected.
Doctors say South Africa has some of the greatest need for penis transplants in the world.
Dozens, some say hundreds, of boys are maimed or die each year during traditional initiation ceremonies.