Thanks to GreekCharmed for the heads up!
Do you think Lost's sideways timeline occurs concurrent with island events or after? — Barry
MICKEY: It's a good question, Barry. When we were chatting with Yunjin Kim about Jin's newfound fertility in the sideways timeline, call us crazy, but we think she revealed something. "Obviously Jin was infertile on the island, but in the flash-sideways he's perfectly healthy," she says. "I don't know if that's because we spent time on the island, even though it's a different lifeline, and the island cured his infertility, therefore in the flash-sideways he's completely healthy. That's what I assumed when I read the script." Sounds like sideways is after, no?
Source: TV Guide