Alexandra's maternity dress, year 1904

Sources:

https://www.hermitagemuseum.org/wps/portal/hermitage/digital-collection/12.%20costumes%2C%20uniform%2C%20accessories/1246596/!ut/p/z1/jY_LDoIwEEV_BfZoC9Ial01NRBRriA_sxjQEsIm0hIILv95qXJmIzm6Sc-fcARxkgCtxk5XopFbiavcTx2dGCPYnFMaMojkkLN2ilG4W0A_B8QXAL0Mg4P_kBwA-fD7-JbAfBG1CkwrwRnSXkVSlBpkfjJ1cm66vC-M5vZKlbmvPEXleGKNbWZgnE2I0w7Yi_5AsV1Mr2aGIsQMNaPgGBmo29T67ryMoies-ALqUaoU!/dz/d5/L2dBISEvZ0FBIS9nQSEh/?lng=en

https://vk.com/album-4269989_240348591

(photo courtesy of The State Hermitage Museum)

A similar dress that also belonged to Alexandra:

(photos courtesy of the House of Romanov (Dom Romanovih) page on VK)