A/74/136 many States, caregivers need to make a specific request and obtain, either separately or jointly, authorization by judicial, social and/or prison authorities to allow the child to live in prison with them. Some States also explicitly refer to further indi cators such as: breastfeeding needs; lack of alternative child -care solutions; suitability of prison accommodation for the child’s development; health of the child; protection of the child’s safety; full parental responsibility and ability to exercise pare nthood; length of the sentence; and the caregiver-child relationship before entering the prison. 53. The study research shows that there is a general lack of adequate prison facilities, such as those with specific mother-child units or other special accommodation for prenatal, perinatal and postnatal care and treatment. 54. If and when the time comes for separation of child and caregiver owing to age limits imposed on co-habitation in prison, this requires careful preparation, well in advance of the child’s departure, and the possibility for continued contact. Questionnaire responses show that such policies are not always in place or implemented in practice. In addition, the child’s best interests are not consistently considered, and a review of the alternative care options is not always undertaken. 55. In some States, support to both caregiver and child, including psychological counselling and enrolment in social programmes, is provided in cooperation with social welfare institutions, educators, child protection authorities and non-governmental organizations, and often depends on the resources available. C. Migration-related detention 56. Research for the study recognizes that migration-related detention of children cannot be considered as a measure of last resort and is never in the best interests of the child and, therefore, should always be prohibited. This applies to unaccompanied and separated children, as well as to children with their families. Detaining children to “keep families together” or for their “protection”, where alternative care is lacking, can never be a justification. 57. Nevertheless, the data collected by the study indicate that, around the world, at least 330,000 children are detained for migration-related purposes per year. At least 77 States are known to still detain children for such reasons, while at least 21 States do not, or claim not to do so. 58. The practice of those States which refrain from placing children in migration detention illustrates that legitimate State interests of regulating migration can be met through policy responses applying non-custodial solutions. These include: open and child-friendly accommodation within child protection systems that are disconnected from migration policies and authorities; periodic reporting; foster families; and other arrangements which prioritize the best interests of the child. 59. States that do detain children on the basis of their migration status offer multiple justifications and employ a range of legal systems and physical locations for doing so, including prisons, closed reception centres, offshore locations, transit shelters and institutional settings. However, immigration detention of children and families is often decided under a procedure that does not respect basic procedural rights, and the conditions of detention are often appalling. 60. Regardless of the conditions of detention, the available evidence shows that immigration detention is harmful to a child’s physical and mental health and exposes the child to the risk of sexual abuse and exploitation. Reports have found that it both aggravates existing health conditions and causes new ones to arise, including anxiety, depression, suicidal ideation and post-traumatic stress disorder. 12/23 19-11838