These specific difficulties affect lexical and sub-lexical processes (visual and phonological processing) implicit in both reading and writing accuracy, and they result from a deficit in the phonological component that is neurobiological in origin. They are characterised by difficulties in the precise and fluid recognition of words and by problems with spelling-in other words, difficulties with the basic components of reading and writing, such as reading and writing accuracy. Pupils who display such difficulties have below the expected reading and writing level for their age, despite receiving adequate instruction for at least six months and having the intelligence to be a good reader.

Specific learning disabilities in reading and writing present disorders in cognitive processes and associative behaviours, which are explained by hypotheses on the biological origin thereof.

Some of these complications can on occasion lead to neuropsychological difficulties, academic difficulties, and even death. Multiple births are associated with prematurity, low Apgar scores, neonatal sepsis, pulmonary hypertension, hyperbilirubinaemia, and restricted intrauterine growth, among others. Twins have been considered in some studies as a psychologically and academically vulnerable population, even though this population is subject to the influence of certain prenatal and perinatal factors-hence, the interest of this study. Future research using larger samples of younger children is required to analyse the relationship between obstetric and neonatal variables and the different basic indicators of reading and writing. Binary logistic regressions applied to each dependent variable indicated that caesarean delivery is a possible independent risk factor for difficulties in reading accuracy and phonetic and visual orthography. Intelligence was measured using the K-BIT test reading and writing variables were evaluated using the Evalúa-1 battery of tests, and clinical records were used to measure gestational, obstetric, and neonatal variables. A total of 124 children born in twin births were evaluated in year one of primary education.

In this retrospective cohort study, the exposed and non-exposed cohorts consisted of children born by caesarean section and vaginal delivery, respectively. The aim of this study was to analyse the relationship between the type of delivery (vaginal or caesarean), as a risk factor, and the likelihood of having learning disabilities in reading (reading accuracy) and writing (phonetic and visual orthography), controlling for the interaction and/or confounding effect of gestational, obstetric, and neonatal variables (maternal age at delivery, gestational age, foetal presentation, Apgar 1, and newborn weight) among six-year-old children born in twin births.

Twin word writer