Structural brain changes occur in a complex manner throughout life, and understanding healthy brain development is crucial for the study of brain abnormalities in various conditions. Diffusion tensor imaging (DTI) is an advanced magnetic resonance imaging technique that provides information about tissue microstructure not accessible via conventional imaging methods. In this dissertation, DTI is used to assess typical brain development, brain abnormalities in fetal alcohol spectrum disorder (FASD), and relationships between cognition and brain structure in both populations. Cross-sectional and longitudinal DTI studies were used to measure brain maturation from childhood to adulthood. Significant, nonlinear changes of diffusion parameters were noted across the brain, with regional variation in the timing and magnitude of development. Most regions experienced rapid maturation during childhood and adolescence, reached a developmental peak during adulthood, and then, during senescence, underwent a reversal of structural changes that occurred more gradually than the initial development. The genu and splenium of the corpus callosum had the earliest development, while frontal-temporal connections and the corticospinal tracts showed the most prolonged maturation trajectories. DTI was also used to examine brain abnormalities in children with FASD, an acquired brain disorder associated with numerous cognitive, behavioural, and emotional difficulties. DTI revealed widespread differences in children with FASD when compared to healthy controls, suggesting extensive structural brain damage. Finally, significant relationships between cognitive abilities and brain structure were observed in both populations. Brain lateralization of a frontal-temporal pathway correlated with two specific cognitive abilities in typically-developing children. Additionally, a significant relationship between brain structure and mathematical ability was observed in the left parietal lobe of children with FASD. Preliminary results demonstrating reading-brain structure correlations in both healthy and FASD groups are also presented. In conclusion, DTI has shown significant age-related changes in the typically-developing human brain, abnormalities in children with FASD, and correlations between brain structure and cognition in both populations. Normative DTI studies such as the ones presented here are important to establish healthy milestones of brain development and degradation, which may then be used to understand abnormalities in a variety of conditions, including FASD.

Vaccination has proven a cost-effective method of managing infectious diseases, but attempts to develop an effective fetal vaccine have proven difficult due to the immaturity of the immune system and the propensity of the developing immune system to induce tolerance to immunizing antigens. This thesis is concerned with the induction of specific immunity in the second trimester ovine fetus using the oral DNA immunization method. In utero oral delivery of naked DNA plasmid was selected as the method of immunization due to previous successes in the third trimester ovine fetus and the immunostimulatory properties of the bacterial DNA backbone, which may help overcome developmental tolerance. Transfection and expression studies in the third trimester ovine fetus revealed the oral mucosal epithelium as the primary site of transgene expression and functionally active antigen was also localized to lymph nodes draining the oral cavity. Efficient transfection and expression of plasmid following oral delivery was specific to the fetus and correlated with a lesser degree of epithelial differentiation. Oral DNA delivery in the second trimester resulted in detection of transgene activity in 100% of treated fetuses and the level of transgene activity was greater than in fetuses treated in the mid-third trimester. Using a plasmid encoding the gene for bovine herpesvirus-1 truncated glycoprotein D (tgD), immunization studies were then conducted in the second trimester fetus. A new lower age limit for fetal immunization was established at 55-60 days gestation (gestation period is 148 days), which coincides with the appearance of lymphocytes in peripheral tissues. Antigen-specific antibody, interferon-× responses and/or neonatal anamnestic responses were detected in 66% of fetuses immunized between 55 and 84 days gestation. The duration of fetal primary immune responses was equivalent to that achieved in young lambs following optimized DNA vaccination, but the magnitude of fetal immune responses was limited. The persistence of immune memory from the second trimester to birth was consistent with experimental data which showed that the duration of immune memory had a stronger correlation to the duration, as compared to the magnitude, of the primary antibody response. Overall, the experiments within showed that oral DNA immunization of the early second trimester fetus is feasible and not associated with the induction of tolerance. These findings suggest that it may be possible to protect against mother-to-child transmission of infectious pathogens by targeting protection at the level of the fetus.

This thesis examines the experiences of parents who are raising their adopted children who have Fetal Alcohol Effects (FAE). Four married couples, and one single mother, who married after she had raised her sons participated in this study. All are white and middle or upper-middle class. Five adoptive mothers and one adoptive father were interviewed, while their spouses contributed to the study by reviewing the interview transcripts, and discussing issues raised within them. Eight children with diagnosed or suspected FAE are discussed. They are Cree or Saulteaux, and are between the ages of nine and 23 . Through multiple in-depth interviews, and the demographic profile form, richly detailed information was recorded on these families' day-to-day lives: the children's school experiences, learning disabilities and behaviour problems, their strengths, their health and interactions with peers; parents' interactions with professionals, treatments and behaviour management strategies they sought or devised, their use of support groups and other forms of social support and encounters with the criminal justice and mental health systems. <p> Grounded theory methodology was used to analyse the data and a conceptual model was constructed to outline the process of redefining parenting which describes the practical and psychological tasks parents perform as the family evolves over time. A central role is taken by the mothers who become advocates for their children as they undertake a quest for the meaning of their children's behaviour, seek a diagnosis, and try to secure services for them. It was found that people with FAE are misunderstood and misdiagnosed because of their anomalous nature, which often leads to stigmatisation. This thesis attempts to dispel these misconceptions, document the parents' and children's struggles, and identify the types of services these families desperately need.

This study described the hospital morbidity of 194,persons with Fetal Alcohol Syndrome (FAS), born between 1973-1992, who were identified through a major referral center for Saskatchewan children with disabling conditions. Computerized provincial hospital separation data were obtained for 84% of 101 males and 77% of 93 females. Complete hospitalization histories were obtained for 128 patients, and partial histories for 29 patients. This data provided information on 1,556 hospitalizations from January 1, 1973 to November 30, 1992. At least 54% of study group members experienced morbidity as newborns, and 83% of all females and 91% of all males had experienced at least one other hospitalization (excluding the newborn stay) during their life (based on provincial data combined with information from patient follow-up and record reviews). By November 1992 (provincial data only), the mean number of hospitalizations (SD) for males and females age 15-19 years was 8.4 (7.0) and 10.2 (8.1), respectively. For children <5 years the mean (SD) was 6.0 (5.8) for males and 3.1 (4.7) for females. Age and sex-specific hospital separation rates for the FAS group (based only on provincial data pooled from fiscal years 1987-91) were compared to the 1989-90 Saskatchewan rates. The 95% confidence intervals for the rate ratios indicated significantly higher rates for both males and females with FAS <1 year, 1-4 years and 5-14 years of age, relative to children in general. Comparisons were made using Saskatchewan Registered Indian rates, since 88% of the study group was Aboriginal. The 95% confidence intervals indicated significantly higher rate ratios for males with FAS in all age groups, and for females with FAS age 5-14 years, relative to Registered Indians. The rate ratios for females <1 year and 1-4 years may not have achieved significance because of a possible bias toward underestimation, given the higher proportions of missing data in these groups. The results suggest the high rates of hospitalization in children with FAS are not explicable solely by factors associated with racial identity or ethnicity.

Background: Sleep disorders have been poorly described in children and adolescents diagnosed with FASD. The objective of this study is to describe the sleep and circadian rhythm characteristics of children with FASD using overnight polysomnography, sleep questionnaires, and the Dim Light Melatonin Onset (DLMO) test. To our knowledge, no comprehensive studies of this nature have been conducted. Methods: Children ages 6-18 years diagnosed with Fetal Alcohol Spectrum Disorder (FASD) were recruited from various FASD clinics to the Youthdale Child and Adolescent Sleep Centre in Toronto. After medical consultation, each participant had one night of overnight polysomnography, as well as an additional night of DLMO. Participants completed various sleep and FASD questionnaires. Results: Significant differences were found when comparing the sleep architecture of FASD participants to normative data. There was a high prevalence of sleep disorders in this sample. Most of the melatonin profiles of the FASD participants were found to be abnormal.

Background: Sleep disorders have been poorly described in children and adolescents diagnosed with FASD. The objective of this study is to describe the sleep and circadian rhythm characteristics of children with FASD using overnight polysomnography, sleep questionnaires, and the Dim Light Melatonin Onset (DLMO) test. To our knowledge, no comprehensive studies of this nature have been conducted. Methods: Children ages 6-18 years diagnosed with Fetal Alcohol Spectrum Disorder (FASD) were recruited from various FASD clinics to the Youthdale Child and Adolescent Sleep Centre in Toronto. After medical consultation, each participant had one night of overnight polysomnography, as well as an additional night of DLMO. Participants completed various sleep and FASD questionnaires. Results: Significant differences were found when comparing the sleep architecture of FASD participants to normative data. There was a high prevalence of sleep disorders in this sample. Most of the melatonin profiles of the FASD participants were found to be abnormal.

This study examines the relationship between maternal emotional attachment to the fetus, beliefs about fetal health locus of control, and use of prenatal testing (i.e., amniocentesis and maternal serum screening). To date, no research has directly addressed the link between these psychosocial variables and prenatal testing uptake. Ninety-one pregnant women at risk for fetal abnormalities (i.e., 35 years of age or older) participated in the study, of whom 35 had no testing, 27 had serum screening, and 29 had amniocentesis in their current pregnancy. Results of a hierarchical multiple regression partially supported the hypothesis that internal and powerful others Fetal Health Locus of Control (Labs & Wurtele, 1986) and prenatal testing status would be predictive of attachment (Prenatal Attachment Inventory; Muller, 1993) over and above the effects of gestational age, maternal age and attitude toward abortion. Fetal Health Locus of Control beliefs regarding ones own role (FHLC-I) in determining the health of ones fetus were found to be predictive of prenatal attachment. Results failed to support the hypothesis that the role of health professionals (FHLC-P) would be predictive of prenatal attachment. As predicted, women who had not used prenatal testing or who underwent amniocentesis tended to have stronger prenatal attachment than those who underwent serum screening only. Results supported the hypotheses that stronger attachment to the fetus would be positively correlated with both FHLC-I and FHLC-P scores. Women who had no testing were found to hold less favourable attitudes toward abortion and rate their religious as stronger than those who had amniocentesis. Emotional attachment to the fetus was stronger among women who had previous miscarriages than those who had not, but did not differ between women who had a previous abortion and those who had not.

This study examines the relationship between maternal emotional attachment to the fetus, beliefs about fetal health locus of control, and use of prenatal testing (i.e., amniocentesis and maternal serum screening). To date, no research has directly addressed the link between these psychosocial variables and prenatal testing uptake. Ninety-one pregnant women at risk for fetal abnormalities (i.e., 35 years of age or older) participated in the study, of whom 35 had no testing, 27 had serum screening, and 29 had amniocentesis in their current pregnancy. Results of a hierarchical multiple regression partially supported the hypothesis that internal and powerful others Fetal Health Locus of Control (Labs & Wurtele, 1986) and prenatal testing status would be predictive of attachment (Prenatal Attachment Inventory; Muller, 1993) over and above the effects of gestational age, maternal age and attitude toward abortion. Fetal Health Locus of Control beliefs regarding ones own role (FHLC-I) in determining the health of ones fetus were found to be predictive of prenatal attachment. Results failed to support the hypothesis that the role of health professionals (FHLC-P) would be predictive of prenatal attachment. As predicted, women who had not used prenatal testing or who underwent amniocentesis tended to have stronger prenatal attachment than those who underwent serum screening only. Results supported the hypotheses that stronger attachment to the fetus would be positively correlated with both FHLC-I and FHLC-P scores. Women who had no testing were found to hold less favourable attitudes toward abortion and rate their religious as stronger than those who had amniocentesis. Emotional attachment to the fetus was stronger among women who had previous miscarriages than those who had not, but did not differ between women who had a previous abortion and those who had not.

Fetal growth potential reflects a complex regulatory system delivered by genetic and environmental factors acting directly on the fetus or through the placenta. Compromise of this potential, as seen in intrauterine growth restriction (IUGR), is associated with increased perinatal mortality and short and long term morbidity. The expression of several genes has been shown to be disturbed in placentas of fetuses with growth restriction. However, the primary causes for these changes have not yet been elucidated. I proposed that epigenetic mechanisms, specifically DNA methylation, may be involved in placental development leading to modulation of the expression of specific genes, and that their altered regulation will impact fetal development and growth. My primary objective was to identify DNA methylation variation in placenta, in association with variation of gene expression and with poor fetal growth. I used a global genomic screening approach, with 24 selected placental samples, from newborns considered IUGR or normal controls, to identify candidate target genomic regions carrying epigenetic alterations. Candidate regions were followed up, by expression analysis of corresponding regulated genes, for associations with altered expression and by targeted methylation analysis in an expanded cohort of 170 samples, for associations with birthweight percentile. I analyzed methylation variation at imprinting centers (IC), gene promoters and CpG islands. In two genome-wide case control screening studies using distinct commercial microarray platforms I identified approximately 68 differentially methylated autosomal candidate genomic regions overlapping gene promoters. Hypomethylated CpGs mapping to gene promoters were found to be more abundant in placentas of growth restricted newborns than in controls. One of the most interesting candidates, WNT2, was analyzed in an extended sample cohort and showed an association of high promoter methylation to low expression as well as low birthweight percentile. This gene is involved in a pathway that diverts cells from programmed apoptosis. It is highly expressed in placenta, and in mice, targeted biallelic inactivation of Wnt2 has been shown to cause poor growth and perinatal death in 50% of the affected pups. These findings support the hypothesis that dysregulation of epigenetic mechanisms are involved in abnormal placental development and can impact fetal growth.

Fetal growth potential reflects a complex regulatory system delivered by genetic and environmental factors acting directly on the fetus or through the placenta. Compromise of this potential, as seen in intrauterine growth restriction (IUGR), is associated with increased perinatal mortality and short and long term morbidity. The expression of several genes has been shown to be disturbed in placentas of fetuses with growth restriction. However, the primary causes for these changes have not yet been elucidated. I proposed that epigenetic mechanisms, specifically DNA methylation, may be involved in placental development leading to modulation of the expression of specific genes, and that their altered regulation will impact fetal development and growth. My primary objective was to identify DNA methylation variation in placenta, in association with variation of gene expression and with poor fetal growth. I used a global genomic screening approach, with 24 selected placental samples, from newborns considered IUGR or normal controls, to identify candidate target genomic regions carrying epigenetic alterations. Candidate regions were followed up, by expression analysis of corresponding regulated genes, for associations with altered expression and by targeted methylation analysis in an expanded cohort of 170 samples, for associations with birthweight percentile. I analyzed methylation variation at imprinting centers (IC), gene promoters and CpG islands. In two genome-wide case control screening studies using distinct commercial microarray platforms I identified approximately 68 differentially methylated autosomal candidate genomic regions overlapping gene promoters. Hypomethylated CpGs mapping to gene promoters were found to be more abundant in placentas of growth restricted newborns than in controls. One of the most interesting candidates, WNT2, was analyzed in an extended sample cohort and showed an association of high promoter methylation to low expression as well as low birthweight percentile. This gene is involved in a pathway that diverts cells from programmed apoptosis. It is highly expressed in placenta, and in mice, targeted biallelic inactivation of Wnt2 has been shown to cause poor growth and perinatal death in 50% of the affected pups. These findings support the hypothesis that dysregulation of epigenetic mechanisms are involved in abnormal placental development and can impact fetal growth.