E/CN.4/2000/4 page 19 illnesses and is provided by health professionals and/or generally trained doctors working within the community at relatively low cost; secondary health care is provided in centres, usually hospitals, and typically deals with relatively common minor or serious illnesses that cannot be managed at community level, using specialty-trained health professionals and doctors, special equipment and sometimes in-patient care at comparatively higher cost; tertiary health care is provided in relatively few centres, typically deals with small numbers of minor or serious illnesses requiring specialty-trained health professionals and doctors and special equipment, and is often relatively expensive. Since forms of primary, secondary and tertiary health care frequently overlap and often interact, the use of this typology does not always provide sufficient distinguishing criteria to be helpful for assessing which levels of health care States parties must provide, and is therefore of limited assistance in relation to the normative understanding of article 12. 10 According to WHO, the stillbirth rate is no longer commonly used, infant and under-five mortality rates being measured instead. 11 Prenatal denotes existing or occurring before birth; perinatal refers to the period shortly before and after birth (in medical statistics the period begins with the completion of 28 weeks of gestation and is variously defined as ending one to four weeks after birth); neonatal, by contrast, covers the period pertaining to the first four weeks after birth; while post-natal denotes occurrence after birth. In this General Comment, the more generic terms pre- and post-natal are exclusively employed. 12 Reproductive health means that women and men have the freedom to decide if and when to reproduce and the right to be informed and to have access to safe, effective, affordable and acceptable methods of family planning of their choice as well as the right of access to appropriate health-care services that will, for example, enable women to go safely through pregnancy and childbirth. 13 The Committee takes note, in this regard, of Principle 1 of the Stockholm Declaration of 1972 which states: “Man has the fundamental right to freedom, equality and adequate conditions of life, in an environment of a quality that permits a life of dignity and well-being”, as well as of recent developments in international law, including General Assembly resolution 45/94 on the need to ensure a healthy environment for the well-being of individuals; Principle 1 of the Rio Declaration; and regional human rights instruments such as article 10 of the San Salvador Protocol to the American Convention on Human Rights. 14 ILO Convention No. 155, art. 4.2. 15 See para. 12 (b) and note 8 above. 16 For the core obligations, see paras. 43 and 44 of the present General Comments. 17 Article 24.1 of the Convention on the Rights of the Child.