Sergey and Helena Rozhenko are foster parent to Worf.
Sergey Rozhenko was a Human male who served as a Starfleet Chief Petty Officer and Warp Field Specialist during the 24th century. He was married to Helena Rozhenko, and together they had a son; Nikolai Rozhenko. Sergey Rozhenko was serving aboard the USS Intrepid, when the ship answered a Klingon distress call, following a Romulan attack on the Khitomer outpost in 2346. In the wreckage of the outpost, Sergey discovered a young Klingon named Worf. Through an act of kindness, Sergey and Helena fostered Worf.