ooopsie baby
n.—Gloss: a baby resulting from an unplanned conception. «Some of us arrived through a loveless act or a perfunctory one. Some of us came by accident. Some of us are called “the ooopsie baby.” Some of us came from unsanctioned moments and are called “love child.”» —“Abortion: What It Takes To Make It To Earth” by Clarissa Pinkola Estés The Moderate Voice Nov. 5, 2007. (source: Double-Tongued Dictionary)