This episode's headline: Capital Gains; Prenatal Care; Abortion Battle. The guests include RICHARD DARMAN, Office of Management & Budget; SEN. GEORGE MITCHELL, Majority Leader; DR. MORTIMER ROSEN, Columbia University; DR. KENNETH WHITTINGTON, American Academy of Family Physicians; CORRESPONDENT: ELIZABETH BRACKETT. Byline: In New York: ROBERT MacNeil; In Washington: JUDY WOODRUFF