Child Development 


Timeliness and completeness of routine childhood vaccinations in children by two years of age in Alberta, Canada

Vineet Saini, PhD, DVM, Shannon E. MacDonald, PhD, RN, Deborah A. McNeil, PhD, RN, Sheila W. McDonald, PhD, MSc, James D. Kellner, MD, MSc, Sarah A. Edwards, MHSc, Victoria Stagg, MSc, and Suzanne Tough, PhD, MSc


OBJECTIVES:  Assessing timeliness and completeness of vaccine administration is important for evaluating the effectiveness of immunization programs. Few studies have reported timeliness, particularly in Canada. The objective of this study was to examine timeliness of the receipt of vaccination for each routine childhood recommended vaccine by 24 months of age among children in a community-based pregnancy cohort in Calgary, Alberta.

METHODS:  Survey data from a community-based pregnancy cohort in Alberta were linked to Public Health vaccination records of children (n = 2763). The proportion of children receiving early, timely, delayed, or no vaccination was calculated. A dose was considered early if it was administered before the recommended age in days as per the vaccination schedule, timely if administered at any time from start of recommended age in days to age in days when delay counts were initiated, and delayed if it was administered on or after age in days when delay counts were initiated. Series completion rates were also calculated.

RESULTS: For multi-dose vaccines, over 80% of children had timely doses at 2, 4 and 6 months. By 12 months, this proportion decreased to 65% (95% CI: 63%–66%) for meningococcal conjugate group C, 61% (95% CI: 59%–62%) for measles antigen-containing vaccines and 64% (95% CI: 62%–65%) for
varicella antigen-containing vaccines. At 18 months, only 55% (95% CI: 53%–56%) of the children had a timely 4th dose of diphtheria, acellular pertussis, tetanus, polio, and Haemophilus influenzae type b vaccine. Eventual series completion rate for all recommended vaccines was 77% (95% CI: 75%–79%).

CONCLUSIONS:  The timeliness and completeness of routine childhood vaccination in preschool children in this community-based pregnancy cohort is lower than provincial targets. Data on timeliness of vaccination can inform further work on barriers and enablers to vaccination in order to meet provincial targets.

Maternal History of Childhood Abuse and Risk of Asthma and Allergy in 2-Year-Old Children

Lianne M. Tomfohr-Madsen, PhD; Hamideh Bayrampour, PhD; Suzanne Tough, PhD


OBJECTIVES: Exposure to child abuse (CA) is associated with an increased risk of developing asthma and allergies; it is unknown if that risk is present across generations. This study investigated if 2-year-old children born to mothers with a history of CA were at an increased risk of receiving a diagnosis of asthma or allergies.

METHODS: Data from 1,551 participants were collected as part of the All Our Babies (AOB) study, a prospective pregnancy cohort. During pregnancy, each woman provided information about her own history of CA, and at 24 months postpartum, she provided information about her child's medical diagnoses. Symptoms of maternal depression and anxiety were assessed during pregnancy and at 24 months postpartum.

RESULTS: Unadjusted models showed that compared to children born to mothers without a history of CA, 2-year-old children born to mothers with a history of CA were more likely to have had a diagnosis of asthma (7.4% vs 4.2%, p = .016) or allergy (15.6% vs 9.2%, p < .001). Maternal symptoms of depression assessed in late pregnancy and symptoms of depression and anxiety at 24 months postpartum were significant mediators of the relationship between maternal CA and 2-year-old asthma diagnosis. Maternal symptoms of depression and anxiety assessed in late pregnancy were also significant mediators of the relationship between maternal CA and 2-year-old allergy diagnosis.

CONCLUSIONS: The results indicate that maternal exposure to CA is associated with increased risk of asthma and allergy in their 2-year-old children; symptoms of maternal depression and anxiety were identified as pathways linking the variables.

Risk and protective factors in early child development: Results from the All Our Babies (AOB) pregnancy cohort

Sheila McDonald, Heather KehlerHamideh BayrampourNonie Fraser-LeeSuzanne Tough


BACKGROUND:Understanding factors that protect against early developmental delay among children who are experiencing adversity can inform prevention and early intervention strategies.

AIMS: To identify risk factors for development delay at one year and protective factors for developmental delay in ‘at risk’ environments (poor maternal mental health and socio-demographic risk).

METHODS AND PROCEDURES: Data was analyzed from 3360 mother-child dyads who participated in the All Our Babies (AOB) pregnancy cohort. Participants completed four questionnaires spanning pregnancy to one year postpartum and provided access to medical records. Risk factors for developmental delay at age one were identified using bivariate methods and multivariable modeling. Protective factors for child development in ‘at risk’ family environments were identified using bivariate analyses.

OUTCOMES AND RESULTS: At one year, 17% of children were developmentally delayed, defined as scoring in the monitoring zone on at least 2 of the 5 developmental domains of the Ages and Stages Questionnaire. Prenatal depression, preterm birth, low community engagement, and non-daily parent-child interaction increased the risk of delay. Protective factors for children in ‘at risk’ environments included relationship happiness, parenting self-efficacy, community engagement, higher social support, and daily parent-child interaction.

CONCLUSIONS AND IMPLICATIONS: The study results suggest that maternal and infant outcomes would be improved, even for vulnerable women, through identification and intervention to address poor mental health and through normalizing engagement with low cost, accessible community resources that can also support parent-child interaction.

Risk of developmental delay: Comparison of late preterm and full term Canadian infants at age 12 months

Marilyn BallantyneKaren M. Benzies, Sheila McDonaldJoyce Magill-Evans, Suzanne Tough


BACKGROUND: Late preterm (34(0/7) to 36(6/7)weeks gestation) infants may experience developmental delays greater than those found in term (≥ 37(0/7)weeks gestation) infants.

AIM: The aim of this study was to compare the risk of developmental delay between late preterm and full-term Canadian born infants at age 12months, and to determine infant and maternal factors associated with risk of delay.

METHODS: A descriptive comparative study was conducted from data available from the All Our Babies community-based, prospective, pregnancy cohort in Calgary, Alberta. Participants were a sample of mothers of 52 infants born late preterm and 156 randomly selected mothers of term infants, matched for infant sex; eligible infants were singleton births. Mothers completed a developmental screening tool, the Ages and Stages Questionnaire, version 3 (ASQ-3), when their infant was age 12months. Corrected age (CA) was used for preterm infants.

RESULTS: Both late preterm and term infants who required neonatal intensive care (NICU) were more likely to demonstrate risk of developmental delay. Compared to term infants, there was a trend for late preterm infants to be at risk of communication and gross motor delay at age 12months CA that was attenuated to the null when adjustments were made for NICU admission and other covariates.

CONCLUSIONS: Infants born between 34 and 41weeks who are admitted to NICU are at increased risk of developmental delay. Early identification of risk provides an opportunity for referral for developmental assessment and early intervention programming.



Risk and Protective Factors for Late Talking: An Epidemiologic Investigation

Beverly Anne Collisson, Susan A. Graham, Jonathan L. Preston, M. Sarah Rose, Sheila McDonald & Suzanne Tough


OBJECTIVE: To identify risk and protective factors for late talking in toddlers between 24 and 30 months of age in a large community-based cohort.

STUDY DESIGN: A prospective, longitudinal pregnancy cohort of 1023 mother-infant pairs in metropolitan Calgary, Canada, were followed across 5 time points: before 25 weeks gestation, between 34-36 weeks gestation, and at 4, 12, and 24 months postpartum. Toddlers who scored ≤10th percentile on The MacArthur-Bates Communicative Development Inventories: Words and Sentences between 24 and 30 months of age were identified as late talkers. Thirty-four candidate characteristics theoretically and/or empirically linked to language development and/or language impairment were collected using survey methodology.

RESULTS: The prevalence of late talking was 12.6%. Risk factors for late talking in the multivariable model included: male sex (P = .017) and a family history of late talking and/or diagnosed speech or language delay (P = .002). Toddlers were significantly less likely to be late talkers if they engaged in informal play opportunities (P = .013), were read to or shown picture books daily (P < .001), or cared for primarily in child care centers (P = .001).

CONCLUSIONS: Both biological and environmental factors were associated with the development of late talking. Biological factors placed toddlers at risk for late talking, and facets of the environment played a protective role. Enveloping infants and toddlers in language-rich milieus that promote opportunities for playing, reading, and sharing books daily may decrease risk for delayed early vocabulary.