Delay In Preschool Children Research Articles

Association Between Excessive Screen Time and Language Delay in Preschool Children

Background: Language is a fundamental medium for expression and comprehension of complex ideas and is acquired from early childhood through both receptive and expressive forms, such as spoken words or sign language. The initial years of life are critical for language development, and the rise of digital device usage during this period prompts an investigation into its potential impact. Objective: This study aims to explore the connection between excessive screen time and language delay in preschool children, a subject of increasing relevance in the digital age. Methods: A cross-sectional approach was taken, gathering data from the caregivers of 318 preschool children in Lahore, using the Ages and Stages Questionnaires-3 (ASQ-3) to measure developmental milestones. SPSS version 23 was employed for statistical analysis. Results: The study included 318 participants, with a gender distribution of 218 females (68.6%) and 100 males (31.4%). In terms of device usage, 209 children (65.7%) used mobile phones, while 91 (28.6%) watched television, and 18 (5.7%) played video games. Regarding screen time duration, 65 children (20.4%) used devices for 1-3 hours, 105 (33.0%) for 3-6 hours, 113 (35.5%) for 6-9 hours, and 35 (11.0%) for more than 9 hours. Notably, for children with over 9 hours of screen time, only 27% met their language developmental milestones at 33 months, which reduced with age, culminating in just 20.1% meeting milestones by 60 months. Conclusion: The study's findings suggest a significant negative correlation between excessive screen time and language development in preschool children, with a clear trend of decreasing milestone achievement with increased screen time. This highlights the need for strategic interventions to manage screen time in early childhood.

Analysis of Factors Related to Speech Delay in Preschool Children in Paud Mampang Prapatan District

Background: Pre-school age children should be given stimuli such as carrying out motorized activities that are trained to get stimulation for all aspects of the child's development and prevent developmental disorders in children. In essence, speaking is an aspect of a child's development that starts from birth. Speech Delay is a tendency where children have difficulty expressing desires or feelings to other people, such as not being able to speak clearly, and lack of mastery of vocabulary which makes the child different from other children his age Purpose: The aim of this research is to analyze the factors that influence speech delay in pre-school age children in PAUD Mampang Prapatan District Methods: The research method used is Descriptive Analysis using Chi Square test data analysis. The sampling technique will be carried out using the Non Random Sampling technique. The research instrument consisted of the KPSP questionnaire, parental knowledge, frequency of gadget use and parenting patterns. Result: The research results showed that there was a relationship between the frequency of gadget use and speech delay (p value 0.051), there was a relationship between parenting patterns and speech delay (p value 0.033) and there was a relationship between parental knowledge and speech delay (p value 0.002). Conclusion: Therefore, the participation of health workers, especially nurses, is needed in studying and analyzing the incidence of speech delay in the aggregate of preschool-aged children

Factors Affecting Speech Delay In Toddlers

The problem of speech delays in preschool children is estimated at 5% of the normal population. It is known that 19% of toddlers have speech and language development disorders, with details of 6.4% speech delay, 4.6% speech and language delay, and 6% language delay. This study aimed to identify factors associated with speech delay in toddlers. This study uses the Literature Review design. The article was taken from the SINTA, Garuda, PubMed, Science Direct, and Google Scholar databases with the keywords (((speech delay) AND toddler) AND influencing factors). The criteria for the articles used are 2018-2021 publications. The articles were selected using the PEOS framework and the JBI Critical Appraisal tools. The results showed that the factors that influenced the occurrence of speech delays included two articles related to gender, one article related to the incidence of physical trauma, two articles related to genetic factors, two articles related to neurological disorders, three articles related to the use of gadgets, and six articles related to parenting. Suggestions that further research can be carried out on the effect of implementing parenting patterns on speech delays in toddlers.

The role of well-child visits in detecting developmental delay in preschool children

BackgroundEarly detection of developmental delay (DD) in preschool children is crucial for counselling parents, initiating diagnostic work-up, and starting early intervention (EI).MethodsWe conducted a register study of all preschool children referred for EI in the Canton of Zurich, Switzerland, in 2017 (N = 1,785) and used an online survey among primary care physicians (PCPs, N = 271) to evaluate the care service of DD children.ResultsPCPs accounted for 79.5% of all referrals by physicians and had correctly referred over 90% of the children in need of EI at an average age of 39.3 months (SD 8.9). In the survey, which represents 59.2% of all pediatricians and 11.3% of all general practitioners in the Canton, PCPs reported performing a mean of 13.5 (range 0–50, SD 10.7) well-child visits per week to preschool children and estimated well-child visits to be the most frequent type of consultation (66.7%) for the identification of DD. Parents’ hesitancy in accepting further evaluation or support were reported by 88.7%.ConclusionsMost preschool children with DD are identified in well-child visits. These visits represent an ideal opportunity for early detection of developmental impairment and initiation of EI. Carefully addressing parents’ reservations could reduce the rate of refusal, thus improving early support for children with DD.

Association of household food insecurity with developmental delay in preschool children: 2018 Ecuadorian Nutrition and Health National Survey.

We investigated the association of household food insecurity (HFI) with developmental delays in 36-59-month-old preschool children (n 7005) using cross-sectional data from the 2018 Ecuadorian National Health and Nutrition Survey. HFI was assessed with the Food Insecurity Experience Scale and developmental delays with the Early Childhood Development Index. Log-binomial regression models estimated the association of HFI with global (overall) developmental delay (GDD) and delays in four individual developmental domains, adjusting for covariates. Nearly half of the children lived in households with marginal (24⋅5 %) or moderate-severe HFI (21⋅7 %). Eighteen percent were identified with GDD. Delays in the individual domains of literacy-numeracy, social-emotional, physical and cognitive development were identified for 64, 21⋅5, 3⋅3 and 3⋅1 %, respectively. GDD was more likely among preschool children from households with marginal (aPR = 1⋅29; 95 % C.I. = 1⋅10, 1⋅49) and moderate-severe HFI (aPR = 1⋅30; 95 % C.I. = 1⋅11, 1⋅51). Social-emotional development delays were also more likely among those from households with marginal (aPR = 1⋅36; 95 % C.I. = 1⋅19, 1⋅56) and moderate-severe HFI (aPR = 1⋅33; 95 % C.I. = 1⋅15, 1⋅54) different from the other three domains. Several other potentially modifiable risk (violent discipline, maternal depressive symptoms) and protective factors (adequate child stimulation, higher maternal education, handwashing with soap/detergent) were also independently associated with GDD and/or literacy-numeracy and cognitive delays. Our findings suggest that HFI is an independent risk factor for GDD and social-emotional developmental delays in Ecuadorian preschoolers. They underscore the importance of strengthening and expanding poverty reduction, food security and early childhood development policies and interventions to improve the opportunities for children to achieve their full developmental potential.

Severe obesity and global developmental delay in preschool children: Findings from a Canadian Paediatric Surveillance Program study.

The co-presentation of severe obesity (SO) and global developmental delay (GDD) in Canadian preschool children has not been examined. However, SO and GDD may require syndromic diagnoses and unique management considerations. To determine (1) minimum incidence; (2) age of onset and risk factors; and (3) health care utilization for co-presenting SO and GDD. Through the Canadian Paediatric Surveillance Program (CPSP), a monthly form was distributed to participants from February 2018 to January 2020 asking for reports of new cases of SO and GDD among children ≤5 years of age. We performed descriptive statistics for quantitative questions and qualitative content analysis for open-ended questions. Forty-seven cases (64% male; 51% white; mean age: 3.5 ± 1.2 years) were included. Age of first weight concern was 2.5 ± 1.3 years and age of GDD diagnosis was 2.7 ± 1.4 years. Minimum incidence of SO and GDD was 3.3 cases per 100,000 for ≤5 years of age per year. Identified problems included school and/or behavioural problems (n = 17; 36%), snoring (n = 14; 30%), and asthma/recurrent wheeze (n = 10; 21%). Mothers of 32% of cases (n = 15) had obesity and 21% of cases (n = 10) received neonatal intensive care. Microarray was ordered for 57% (n = 27) of children. A variety of clinicians and services were accessed. As reported by CPSP participants, challenges faced by families and health service access were barriers to care. Children with SO and GDD have multiple comorbidities, and require early identification and referral to appropriate services. These cases may also benefit from additional testing to rule out known genetic obesity syndromes.

Don't delay on identifying SEN

Identifying developmental delay in pre-school children is a priority area for early years professionals. Sian Marsh takes a look at this important area, with a setting case study and the roll out of a new Level 3 SENCo qualification.

Pemantauan Kemampuan Anak dalam Mencapai Tumbuh Kembang yang Optimal dengan Deteksi Tumbuh Kembang pada Anak Usia Prasekolah

This community service aims to monitor the growth and development of pre school children at PAUD Tarbiyatussibyan. The method used is a lecture and measuring growth and development. Monitoring and measurement of growth and development was carried out on 30 children in September-Nopember 2021. The results obtained were 100% of the participants had normal growth and development. Monitoring of growth and development should be done regularly at least once every 3 months as an effort to detect early developmental delays in pre-school children.

Fundamental Motor Skill Delays in Preschool Children With Disabilities: 2012 National Youth Fitness Survey

Delays in fundamental motor skill (FMS) competency have been observed in a variety of children with disabilities. However, evidence of FMS delays is largely limited to small, geographically specific, limitedly diverse, and non-representative samples. The purpose of this study was to examine the association between FMS competency and reported disability status among pre-school children, ages 3–5 years, using the 2012 National Youth Fitness Survey (NYFS). In total, 329 preschool children (49% female; 4.00 ± 0.04 years of age) from the 2012 NYFS completed the Test of Gross Motor Development−2, including 43 preschoolers identified with a disability based on parental report (44% female; 4.20 ± 0.16 years). Associations were examined with logistic regression using sampling weights. Poor FMS competency, defined as gross motor quotient scores ≤ 79, was observed in significantly more children with disabilities (29%) than children without disabilities (10%, OR = 3.5, p = 0.04). While not statistically significant, there was a growing disparity in FMS competency at age 5 (41 vs. 11%) compared to age 3 (15 vs. 9%, OR = 1.80, p = 0.30). The results provide additional evidence for poor FMS competency among pre-school children with disabilities. FMS should be an early part of comprehensive assessments for all children suspected of disability or development delay as it is critical to identify and intervene upon FMS delays before discrepancies can widen.

HUBUNGAN PERAN ORANG TUA DALAM STIMULASI BERMAIN DENGAN PERKEMBANGAN ANAK PRASEKOLAH DI MASA PANDEMI COVID – 19 (Studi di TK Dharma Wanita RSJ Dr Radjiman Wediodiningrat Lawang)

The role of parents in stimulating play for their children is very important and influential in the development of children. The COVID-19 pandemic situation that is happening all over the world makes parents, feel worried and anxious if their children are infected with this dangerous virus. The impact of this problem is the occurrence of developmental delays in preschool children. The purpose of this study is to analyze the relationship parents role in play stimulation and the development of preschool children during the covid 19 pandemic at Dharma Wanita Kindergarten, Dr. Radjiman Wediodiningrat Lawang Hospital. The research design used cross sectional analytic. The population in this study were parents who had preschool children at Dharma Wanita Kindergarten, RSJ Dr Radjiman Wediodiningrat Lawang. The sample as many as 38. The sampling technique was simple random sampling. The independent variable is the role of parents and the dependent variable is the development of preschool children during the Covid 19 pandemic. Data were collected using a questionnaire. Data processing by editing, coding, scoring, tabulating and analysis using Spearman's Rank test with alpha 0.05. The results of this study were obtained from 38 respondents, mostly (52.6%) the role of parents was good, most (68.4%) development was according to the age of the child. Spearman rank test shows that the significance value = 0.001 < (0.05), so H1 was accepted. The conclusion is that there is relation of parents role in play stimulasion to preschool development during the Covid 19 pandemic.

The combined effects of nucleotide-binding domain-like receptor protein 3 polymorphisms and levels of blood lead on developmental delays in preschool children

Nucleotide-binding domain-like receptors protein 3 (NLRP3) inflammasomes are associated with neuroinflammation and multiple NLRP3 genes regulate NLRP3 expression. Our study aimed to investigate the association of NLRP3 polymorphisms with developmental delay in preschool children. We also explored whether NLRP3 polymorphisms modified the effects of total urinary arsenic and blood cadmium and lead to developmental delays. A total of 178 children with developmental delays and 88 healthy children were analyzed for urinary arsenic concentrations and red blood cell lead and cadmium concentrations. We examined the genotypes of fifteen common single-nucleotide polymorphisms in NLRP3. We observed that levels of total urinary arsenic and blood lead were significantly associated with developmental delay. The NLRP3rs10754555 CG versus CC/GG, NLRP3rs12048215 AG versus AA/GG, and NLRP3rs12137901 TC/TT versus CC genotype showed a lower odds of developmental delay, with the odds ratio (OR) and 95% confidence interval (CI) = 0.38 (0.19–0.75), 0.52 (0.27–0.99), and 0.33 (0.12–0.90), respectively. Children with the NLRP3rs10754555 CC/GG genotype and high blood lead levels had a significant multiplicative interaction with developmental delay [OR (95% CI) = 9.74 (3.59–26.45)]. This study found evidence that suggested the joint effects of NLRP3rs10754555 CC/GG genotype and high blood lead levels on developmental delays.

156 Evening Light-Induced Circadian Phase Shift in Preschool-Aged Children

Abstract Introduction In adults, exposure to light at night delays the timing of the circadian clock in a dose-dependent manner with intensity. Although children’s melatonin levels are highly suppressed by evening bright light, the sensitivity of young children’s circadian timing to evening light is unknown. This research aimed to establish an illuminance response curve for phase delay in preschool children as a result of exposure to varying light intensities in the hour before bedtime. Methods Healthy children (n=36, 3.0 – 4.9 years, 39% males), participated in a 10-day protocol. For 7 days, children followed a strict parent-selected sleep schedule. On Days 8-10, an in-home dim-light assessment was performed. On Day 8, dim light melatonin onset (DLMO) was measured through saliva samples collected in 20-30-min intervals throughout the evening until 1-h past habitual bedtime. On Day 9, children were exposed to a white light stimulus (semi-randomly assigned from 5lx to 5000lx) for 1-h before their habitual bedtime, and saliva was collected before, during, and after the exposure. On Day 10, children provided saliva samples in the evening for 2.5-h past bedtime for a final DLMO assessment. Phase angle of entrainment (habitual bedtime – DLMObaseline) and circadian phase delay (DLMOfinal – DLMObaseline) were computed. Results Final DLMO (Day 10) shifted between -8 and 123 minutes (M = 56.1 +/- 33.6 min; negative value = phase advance, positive value = phase delay) compared with DLMO at baseline (Day 8). Raw phase shift did not demonstrate a dose-dependent relationship with light intensity. Rather, we observed a robust phase delay across all intensities. Conclusion These data suggest preschoolers’ circadian clocks are immensely sensitive to a large range of light intensities, which may be mechanistically influenced by less mature ophthalmologic features (e.g. clearer lenses, larger pupils). With young children’s ever-growing use of light-emitting devices and evening exposure to artificial lighting, as well as the prevalence of behavioral sleep problems, these findings may inform recommendations for parents on the effects of evening light exposure on sleep timing in early childhood. Support (if any) This research was supported with funds from the Eunice Kennedy Shriver National Institute of Child Health &amp; Human Development (R01-HD087707).

Association of screen time with parent-reported cognitive delay in preschool children of Kerala, India

BackgroundScreen use is increasing rapidly among preschool children and excess screen use in these children has been associated with cognitive side effects and speech delay. We undertook this study to estimate the risk associated with screen time in children, parental supervision, and parent-reported cognitive development among preschool children aged 2–5 years.MethodsA cross-sectional study was done between July 2019 and January 2020 involving parents of all students aged 2–5 years, attending 2 kindergarten schools in Thiruvalla using a self-administered questionnaire. Parents also used the Werner David Development pictorial scale (WDDPS), a screening tool to report cognitive development. The schools were sampled based on convenience.ResultsOf the 189 children included in the study, 89.4% had excess screen use (> 1 h per day) and the average use was 2.14 h. 45.0% of parents supervised screen use inconsistently (self-reported). Meal-time screen use (OR 3.8, 95% CI 1.3–10.8), receiving screen on demand (OR 3.7, 95% CI 1.2–11.3), and using devices other than computers (OR 6.5, 95% CI 1.6–26.8) were significantly associated with excess screen use in pre-school children. Similarly, those children with inconsistently supervised screen time were significantly more likely to have suspected deficits in attention (OR 3.2, 95% CI 1.3–8.2), intelligence (OR 4.1, 95% CI 1.3–13.3), and social skills (OR 15.3, 95% CI 1.9–121.2), compared to children whose screen use was consistently supervised.ConclusionScreen time in the majority of preschool children is above the recommended limits, and inconsistent supervision by parents was seen in almost half of the study participants. Inconsistently supervised screen time is associated with suspected cognitive delays in children.

Combined effect of polymorphisms of MTHFR and MTR and arsenic methylation capacity on developmental delay in preschool children in Taiwan.

Polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MTR) are related to cognitive dysfunction and mental disability. These genes, along with folate and vitamin B12 levels, are regulators of one-carbon metabolism, which synthesizes S-adenosylmethionine (SAM) as a methyl donor for arsenic methylation. The aim of this study was to explore whether polymorphisms of MTHFR and MTR influence arsenic methylation capacity and plasma folate and vitamin B12 levels and if these influences cause developmental delay in preschool children. A total of 178 children with developmental delay and 88 without developmental delay were recruited from August 2010 to March 2014. A high-performance liquid chromatography-hydride generator and atomic absorption spectrometer were used to determine urinary arsenic species. Plasma folate and vitamin B12 concentrations were measured by SimulTRAC-SNB radioassay. Polymorphisms of MTHFR C677T, MTHFR A1298C, and MTR A2756G were examined by polymerase chain reaction and restriction fragment length variation. The results show that MTHFR C677T C/T and T/T genotypes had a lower risk of developmental delay than the C/C genotype (odds ratio [OR] = 0.47; 95% confidence interval, 0.26-0.85). Subjects with the MTHFR C677T C/C genotype had significantly lower plasma folate and vitamin B12 levels than those with the MTHFR C677T C/T and T/T genotype. The MTHFR C677T C/C genotype combined with high total urinary arsenic and poor arsenic methylation capacity indices significantly increased the OR of developmental delay in a dose-response manner. This is the first study to show the combined effect of MTHFR C677T genotype and poor arsenic methylation capacity on developmental delay.

Factors affecting language delay in preschool children

Factors affecting language delay in preschool children

Factors associated with risk of developmental delay in preschool children in a setting with high rates of malnutrition: a cross-sectional analysis of data from the IHOPE study, Madagascar

Background50% of Malagasy children have moderate to severe stunting. In 2016, a new 10 year National Nutrition Action Plan (PNAN III) was initiated to help address stunting and developmental delay. We report factors associated with risk of developmental delay in 3 and 4 year olds in the rural district of Ifanadiana in southeastern Madagascar in 2016.MethodsThe data are from a cross-sectional analysis of the 2016 wave of IHOPE panel data (a population-representative cohort study begun in 2014). We interviewed women ages 15–49 using the MICS Early Child Development Indicator (ECDI) module, which includes questions for physical, socio-emotional, learning and literacy/numeracy domains. We analyzed ECDI data using standardized z scores for relative relationships for 2 outcomes: at-risk-for-delay vs. an international standard, and lower-development-than-peers if ECDI z scores were > 1 standard deviation below study mean. Covariates included demographics, adult involvement, household environment, and selected child health factors. Variables significant at alpha of 0.1 were included a multivariable model; final models used backward stepwise regression, clustered at the sampling level.ResultsOf 432 children ages 3 and 4 years, 173 (40%) were at risk for delay compared to international norms and 68 children (16.0%) had lower-development than peers. This was driven mostly by the literacy/numeracy domain, with only 7% of children considered developmentally on track in that domain. 50.5% of children had moderate to severe stunting. 76 (17.6%) had > = 4 stimulation activities in past 3 days.Greater paternal engagement (OR 1.5 (1.09, 2.07)) was associated with increased delay vs. international norms. Adolescent motherhood (OR. 4.09 (1.40, 11.87)) decreased children’s development vs. peers. Engagement from a non-parental adult reduced odds of delay for both outcomes (OR (95%CI = 0.76 (0.63, 0.91) & 0.27 (0.15, 0 48) respectively). Stunting was not associated with delay risk (1.36 (0.85, 2.15) or low development (0.92 (0.48, 1.78)) when controlling for other factors.ConclusionsIn this setting of high child malnutrition, stunting is not independently associated with developmental risk. A low proportion of children receive developmentally supportive stimulation from adults, but non-parent adults provide more stimulation in general than either mother or father. Stimulation from non-parent adults is associated with lower odds of delay.

Use of the method for the formation of the concepts of size and shape in preschool children for clinical research

The goal of the present study was to test the method of forming or actualizing preverbal concepts in the conditions of an independent search for a task solution in order to use the method in clinical practice. The conditions of the absence of researchers instructions allow: 1) to compare in ontogenetic and clinical aspects; 2) to develop the skills of an independent search for solutions in problem situations; 3) to improve the creative potential of a child; 4) to develop the ability to achieve a goal. The advantage of using the preverbal concepts of size and shape is that this method can be applied to children of primary preschool age and children with a delay in speech development. To test the method, 7 healthy children of the middle preschool age (4-5-year-old children) were selected. The first task was to form or actualize the concept of a bigger or smaller size in children during the simultaneous presentation of 4 flat or volume geometrical figures. The second task was to form or actualize the concept of a flat or volumetric object among simultaneously presented 4 figures of the same size (small, medium or big). To get reward children should have chosen the figure, which was different from the other 3 ones in a trial during the formation of both the concepts. In the both tasks, we calculated the quantity of trials, which were needed for the single attainment or excess of the 70% level of the correct task performance per each type of learning. The behavioral results showed that the learning speeds during the formation of the concepts of the bigger/smaller size and flat/volumetric shape did not significantly differ from each other. It could be suggested that those concepts were equally important for the 4-5-year-old children. The study showed that the concept formation model is a convenient psychological method for testing the level of the development of the higher cognitive functions in participants and its use is possible in clinical practice with the parallel recording of the brain activity (EEG, evoked potentials etc.) in children in the process of their performing cognitive tasks. The described model is promising for identifying intellectual developmental delays in preschool children and can be used to test children with various cognitive abnormalities.

Prenatal, perinatal and postnatal risk factors associated with fine motor function delay in pre-school children in Neiva, Colombia

ABSTRACT The assessment of fine motor skills in preschoolers becomes a determining indicator of a child's health conditions. The objective of the present study was to determine the prenatal, perinatal and postnatal risk factors of children with delayed development of fine motor skills. The participants were 240 boys and girls from 2 to 5 years old from the Child Development Centers of Neiva Huila Colombia. Abbreviated Developmental Scale (EAD-3) was applied to assess fine motor skills at children. Sociodemographic survey was applied to mothers to collect prenatal, perinatal and post-natal background information of the boys and girls who were part of the study. The results showed that there is a correlation between fine motor skills and prenatal risk factors such as the use of psychoactive substances and signs of abortion during pregnancy. As well as perinatal risk factors such as gestation time, duration of delivery, birth weight and postnatal risk factors such as constant falls.

Preterm birth and risk for language delays before school entry: A sibling-control study.

We investigated whether children born preterm are at risk for language delay using a sibling-control design in the Norwegian Mother and Child Cohort Study (MoBa), conducted by the Norwegian Institute of Public Health. Participants included 26,769 siblings born between gestational weeks 23 and 42. Language delay was assessed when the children were 1.5, 3, and 5 years old. To adjust for familial risk factors, comparisons were conducted between preterm and full-term siblings. Pregnancy-specific risk factors were controlled for by means of observed variables. Findings showed that preterm children born before week 37 had increased risk for language delays at 1.5 years. At 3 and 5 years, only children born before week 34 had increased risk for language delay. Children born weeks 29-33 and before week 29 had increased risk for language delay at 1.5 years (RR = 4.51, 95% CI [3.45, 5.88]; RR = 10.32, 95% CI [6.7, 15.80]), 3 years (RR = 1.50, 95% CI [1.02, 2.21]; RR = 2.78, 95% CI [1.09, 7.07]), and 5 years (RR = 1.63, 95% CI [1.06, 2.51]; RR = 2.98, 95% CI [0.87, 10.26]), respectively. In conclusion, children born preterm are at risk for language delays, with familial confounders only explaining a moderate share of the association. This suggests a cause-effect relationship between early preterm birth and risk for language delay in preschool children.

Association of plasma folate, vitamin B12 levels, and arsenic methylation capacity with developmental delay in preschool children in Taiwan.

Developmental delay has been associated with inefficient arsenic methylation capacity in preschool children. Folate and vitamin B12 are important nutrients that produce s-adenosylmethionine during single-carbon metabolism and provide methyl groups for arsenic methylation. The aim of the present study was to explore whether plasma folate and vitamin B12 levels influence arsenic methylation capacity and in turn are related to developmental delay in preschool children. A case-control study was conducted in 178 children with developmental delay and 88 normal children, who were recruited from Shin Kong Wu Ho-Su Memorial Teaching Hospital from August 2010 to March 2014. Arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MMAV), and dimethylarsinic acid (DMAV) in the urine was determined by high-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. Plasma folate and vitamin B12 levels were measured using a SimulTRAC-SNB radioassay. The results show that the combination of high plasma folate and high vitamin B12 levels were correlated with efficient arsenic methylation capacity (low MMAV%, low InAs%, and high DMAV%). High MMAV% significantly increased and high DMAV% and secondary methylation index decreased the odds ratio (OR) of developmental delay in a dose-dependent manner in both low plasma folate and low vitamin B12 (low/low) groups; the multivariate OR and 95% confidence interval were 5.01 (0.83-30.06), 0.21 (0.04-1.23), and 0.20 (0.03-1.20), respectively. This is the first study to show that the combination of high plasma folate and high vitamin B12 levels increases arsenic methylation capacity and indirectly decreases the OR of developmental delay in preschool children.