Citing an unidentified source, Life & Style Weekly reported in its current issue that Spears, 23, aspires to recreate Demi Moore's famous 1991 Vanity Fair cover shot.
"The negotiations are in motion," said the source. "Britney desperately wants to do it and knows she has to stay in good shape."
Life & Style Weekly said Vanity Fair editors hope to shoot Spears in her seventh month so the issue can hit newsstands before she gives birth this fall.
"Britney loves being pregnant," said the source, "and she loves her new body."