Assessment of Motor Milestones in Twins

Abstract

The aim of this study was to investigate the reliability of obtaining through mailed surveys maternal reports of specific major motor milestones achievement. To accomplish this aim we compared and contrasted mailed survey data and telephone interview data on a series of questions about age at which motor milestones were achieved. We used monthly telephone interviews with mothers of 238 twin pairs, beginning at age 6 months, which ascertained the age at which each specific milestone was met. The contrasting ‘through the mail’ survey was sent after the second birthday of an independent group of children, and included 463 twin pairs. All twins were born between March 2003 and March 2004. Comparisons were made for the following 5 milestones: sitting without support, hands and knees crawling, turning from back to belly, standing without support, and walking without support. There was no difference between the concurrent telephone interviews and the retrospective through the mail survey on any of the landmarks, except ‘standing without support’. From this work we conclude that data on achieving milestones can be reliably obtained through the mail using retrospective surveys when the children are 2 years of age.

Age of Achievement of Gross Motor Milestones in Infancy and Adiposity at Age 3 Years

“…Also, although there is evidence that maternal report of motor milestones is valid [8, 19, 42], mothers in this study may not have stated their children's milestone achievement accurately. Mothers were not informed that they would be asked to report their children's gross motor milestones prior to enrollment in the study.…”

“…In our study, however, we asked mothers to recall their children's motor milestone achievement at fairly regular intervals in an effort to improve the accuracy of reporting. A previous study assessing the validity of maternal report found that mothers were able to recall accurately their children's gross motor milestone attainment during infancy even after their children had reached 2 years of age [8]. …”

“…Mothers reported age of achievement by month of each motor milestone on questionnaires (close-ended) when their infants were 6 months, 1 year, and 2 years of age. Previous studies have found maternal recall and report of their children's milestone achievement to be accurate [8, 19, 42], and this method of motor milestone assessment has been used in recent studies [43, 44]. …”

Gross Motor Milestones and Subsequent Development

“…Previous reports confirm the validity of maternal reports on child development and support the accuracy of maternal rating on infant’s motor milestone achievement. 12,13 In particular, questionnaires administered repeatedly and with short intervals minimize the recall bias and make it less likely that mothers erred in their reporting of milestone ages. We hypothesized that delayed motor development is adversely associated with a child’s adaptive, social, communication, motor, and cognitive skills in both singletons and twins.…”

Developmental and behavioral outcomes of uncomplicated monochorionic diamniotic twins born in the third trimester

“…Screening tests are designed to identify groups at sufficient risk to warrant a more in-depth evaluation, rather than providing a quantitative assessment or diagnosis and therefore potentially have a higher rate of positive results 51. Furthermore, it has been suggested that this problem is more pronounced for twins, where parents must remember two separate developmental trajectories and are likely to compare and contrast the two children, potentially leading to an overestimation or under-estimation of differences between the two 52. In any event, the observed differences between parent-structured questionnaire report of difficulties (eg, CDC, CBCL) and parent qualitative report of previously diagnosed difficulties merit investigation in future studies.…”