Lamont M A
Department of Child Health, Southampton General Hospital, England.
J Ment Defic Res. 1988 Jun;32 ( Pt 3):221-32. doi: 10.1111/j.1365-2788.1988.tb01408.x.
A study of 169 midly mentally retarded children included consideration of social class, medical risk factors, sibship position, family size and parental education. Ninety-four (56%) children were from social class IV or V. Medical risk factors were identified in 71 (42%) children overall: the prevalence fell from 55% in social class II to 30% in social class V. Prenatal factors were identified in 22 children of whom 14 were third or later born in their sibship: this may reflect increased maternal age at birth. Perinatal events had been reported in 41 children, 20 of whom were in social class III; there was no clear relationship to sibship position. Seven of eight postnatal events had occurred in children in social class II or III. Children in social class IV or V did not appear to be at increased risk of retardation from environmental medical events. Firstborn children were over-represented in the survey, with a minor shift towards fourth-or later-born children. Average family size was 3.25 children (general population 2.0 children). The prevalence of medical risk factors was lowest (18%) in children from large sibships in social class V. Both parents of 86 children had had educational problems: this included 13 children in social class III. Thirty-eight (33%) of these children had medical risk factors, compared with 43/83 (51%) in children where at least one patient had achieved average education. Thirty children had no medical risk factor, nor any history of parental learning difficulty.
一项针对169名轻度智力发育迟缓儿童的研究涵盖了社会阶层、医学风险因素、出生顺序、家庭规模和父母教育程度等方面。九十四名（56%）儿童来自社会阶层IV或V。总体上，71名（42%）儿童被确定存在医学风险因素：患病率从社会阶层II的55%降至社会阶层V的30%。在22名儿童中发现了产前因素，其中14名是其家庭中的第三个或更晚出生的孩子：这可能反映出母亲生育时年龄增大。41名儿童报告了围产期事件，其中20名处于社会阶层III；这与出生顺序没有明显关系。八项产后事件中的七项发生在社会阶层II或III的儿童中。社会阶层IV或V的儿童似乎并未因环境医学事件而增加智力发育迟缓的风险。调查中头胎儿童的比例过高，且有向第四胎或更晚出生儿童的轻微转变。平均家庭规模为3.25个孩子（普通人群为2.0个孩子）。社会阶层V中来自大家庭的儿童医学风险因素患病率最低（18%）。86名儿童的父母双方都有教育问题：这包括社会阶层III中的13名儿童。这些儿童中有38名（33%）存在医学风险因素，而至少有一方父母达到平均教育水平的儿童中这一比例为43/83（51%）。30名儿童既没有医学风险因素，也没有父母学习困难的病史。
