Baby crib comprising: - an enclosure having side walls (41, 42, 43, 44) made of a flexible material and defining a space configured to receive a baby, the enclosure also having a bottom wall made of a flexible material, said side walls (41, 42, 43, 44) having top portions (41a, 42a, 43a, 44a) delimiting a top opening of the enclosure; - an upper frame configured to be attached to said enclosure, - a lower frame configured to support said bottom wall, said upper frame being spaced apart from said lower frame along a longitudinal direction (X-X), - support members attached to said upper frame and said lower frame, said support members being configured to rest on a ground surface and being spaced apart along a transverse direction (Y-Y) perpendicular to said longitudinal direction (X-X), wherein - said upper frame comprises a first part firmly attached to said support members and a second part, said first part being attached to a first top portion of the first side wall of the enclosure, said second part being attached to a second top portion of the second side wall of the enclosure, - said second part is pivotally coupled with said support members to move reversibly from a first position to a second position to move said second part relative to said first part; characterized in that: - in the first position, a first distance is defined and measured along the longitudinal direction (X-X) between the second top portion and the bottom wall, - in the second position, a second distance is defined and measured along the longitudinal direction (X-X) between the second top portion and the bottom wall, - said second distance is smaller than said first distance. - an enclosure having side walls (41, 42, 43, 44) made of a flexible material and defining a space configured to receive a baby, the enclosure also having a bottom wall made of a flexible material, said side walls (41, 42, 43, 44) having top portions (41a, 42a, 43a, 44a) delimiting a top opening of the enclosure; - an upper frame configured to be attached to said enclosure, - a lower frame configured to support said bottom wall, said upper frame being spaced apart from said lower frame along a longitudinal direction (X-X), - support members attached to said upper frame and said lower frame, said support members being configured to rest on a ground surface and being spaced apart along a transverse direction (Y-Y) perpendicular to said longitudinal direction (X-X), - said upper frame comprises a first part firmly attached to said support members and a second part, said first part being attached to a first top portion of the first side wall of the enclosure, said second part being attached to a second top portion of the second side wall of the enclosure, - said second part is pivotally coupled with said support members to move reversibly from a first position to a second position to move said second part relative to said first part; - in the first position, a first distance is defined and measured along the longitudinal direction (X-X) between the second top portion and the bottom wall, - in the second position, a second distance is defined and measured along the longitudinal direction (X-X) between the second top portion and the bottom wall, - said second distance is smaller than said first distance.