Miles and Keiko were married on October 24, 2367, after after Data introduced them aboard the USS Enterprise-D. (TNG: "Data's Day" ) Their first child, Molly, was born in 2368. (TNG: "Disaster" ) Miles and Keiko went to Earth in 2369 to celebrate the 100th birthday of Miles' mother. (DS9: "Dax") After the O'Briens moved to Deep Space 9, their second child and first son, Kirayoshi, was born in early 2373 after being carried to term by surrogate mother Kira Nerys. (DS9: "Body Parts", "The Begotten")