The Wii U sold 55,000 units in the US last month and is still outsold by its predecessor, according to estimates published by Wedbush analyst Michael Pachter.
Wii U sales will be down 19 per cent month-over-month with 55,000 units sold, while Wii sales will be down 16 per cent year-over-year in the month of April, totalling 75,000 units sold.
Meanwhile, Pachter estimates that 3DS sales have increased 46 per cent, totaling 185,000 units sold during April.
Noting the traditionally slow retail performance at the cusp of a new hardware generation, Pachter expects a "negative momentum" across the board until the release of the PS4 and Xbox Infinity.
Still, Pachter expects less dramatic falls for both Sony and Microsoft's consoles, with a 5 per cent year-on-year change for the PS3 and 13 per cent for the Xbox 360. More substantial is the 57 per cent year-on-year sales decline of the Vita, which the analyst predicts has sold 30,000 during April.
The next-generation is expected to commence for each console manufacturer by the end of the year, with new reports suggesting Sony will release its PlayStation 4 globally in 2013.
Microsoft will unveil its new console - expected to be titled 'Xbox Infinity' - on May 21.
The NPD Group retail sales report is due later this week.