Deanna is impregnated by an unknown alien life-form, and Dr. Katherine Pulask...
Star Trek: The Next Generation
Season 2 Episode 14: The Icarus Factor
Riker's delight at being offered a command of the USS Aries turns to frustration when the man sent to prepare him for his mission is his estranged father; Worf's behavior leads Wesley to delve into Klingon tradition.