Associations of maternal folic acid supplementation and folate concentrations during pregnancy with foetal and child head growth: the Generation R Study.

PURPOSE: Folic acid supplementation during pregnancy has been associated with a reduced risk of common neurodevelopmental delays in the offspring. However, it is unclear whether low folate status has effects on the developing brain. We evaluated the associations of maternal folic acid supplementation and folate concentrations during pregnancy with repeatedly measured prenatal and postnatal head circumference in the offspring. METHODS: Within a population-based prospective cohort, we measured maternal plasma folate concentrations at approximately 13 weeks of gestation (90 % range 10.5-17.2) and assessed folic acid supplementation by questionnaire (2001-2005). Up to 11 repeated measures of head circumference were obtained during foetal life (20 and 30 weeks of gestation) and childhood (between birth and age 6 years) in 5866 children (2002-2012). RESULTS: In unadjusted models, foetal head growth was 0.006 SD (95 % CI 0.003; 0.009, P < 0.001) faster per week per 1-SD higher maternal folate concentration. After adjustment for confounders, this association was attenuated to 0.004 SD per week (95 % CI 0.000; 0.007, P = 0.02; estimated absolute difference at birth of 2.7 mm). The association was independent of overall foetal growth. No associations were found between maternal folate concentrations and child postnatal head growth. Preconceptional start of folic acid supplementation was associated with larger prenatal head size, but not with prenatal or postnatal head growth. CONCLUSIONS: Our results suggest an independent, modest association between maternal folate concentrations in early pregnancy and foetal head growth. More research is needed to identify whether specific brain regions are affected and whether effects of folate on foetal head growth influence children's long-term functioning.

Folate concentrations during pregnancy and autistic traits in the offspring. The Generation R Study.

In a population-based study, we examined the associations of maternal plasma folate concentrations at 13 weeks of gestation and prenatal folic acid supplement use with autistic traits in the offspring at the age of six years. Parent-reported autistic traits were assessed using the Social Responsiveness Scale short form. Maternal folate was not associated with autistic traits in the offspring. In contrast, prenatal folic acid use was associated with less child autistic traits. Future research should focus on the timing of the potential effect of prenatal folate on the development of autistic traits in combination with clinical diagnosis of autism in the offspring.

Infant brain structures, executive function, and attention deficit/hyperactivity problems at preschool age. A prospective study.

BACKGROUND: Neuroimaging findings have provided evidence for a relation between variations in brain structures and attention deficit/hyperactivity disorder (ADHD). However, longitudinal neuroimaging studies are typically confined to children who have already been diagnosed with ADHD. In a population-based study, we aimed to characterize the prospective association between brain structures measured during infancy and executive function and attention deficit/hyperactivity problems assessed at preschool age. METHODS: In the Generation R Study, the corpus callosum length, the gangliothalamic ovoid diameter (encompassing the basal ganglia and thalamus), and the ventricular volume were measured in 784 6-week-old children using cranial postnatal ultrasounds. Parents rated executive functioning at 4 years using the behavior rating inventory of executive function-preschool version in five dimensions: inhibition, shifting, emotional control, working memory, and planning/organizing. Attention deficit/hyperactivity problems were assessed at ages 3 and 5 years using the child behavior checklist. RESULTS: A smaller corpus callosum length during infancy was associated with greater deficits in executive functioning at 4 years. This was accounted for by higher problem scores on inhibition and emotional control. The corpus callosum length during infancy did not predict attention deficit/hyperactivity problem at 3 and 5 years, when controlling for the confounders. We did not find any relation between gangliothalamic ovoid diameter and executive function or Attention deficit/hyperactivity problem. CONCLUSIONS: Variations in brain structures detectible in infants predicted subtle impairments in inhibition and emotional control. However, in this population-based study, we could not demonstrate that early structural brain variations precede symptoms of ADHD.

Maternal folate status in early pregnancy and child emotional and behavioral problems: the Generation R Study.

BACKGROUND: Maternal prenatal folate status has been linked to neurodevelopmental disorders, but the association with child emotional and behavioral problems is unclear. OBJECTIVES: We assessed the association of maternal folate status during pregnancy with child emotional and behavioral problems. Also, we examined whether any association between folate status and child problems is a consequence of maternal folic acid supplement use or variation in maternal MTHFR genotype. DESIGN: Within a population-based cohort, we measured maternal plasma folate concentrations in early pregnancy and assessed folic acid supplement use by questionnaire. Mothers of European descent were genotyped for the MTHFR 677 C→T polymorphism. Child emotional and behavioral problems were assessed with the Child Behavior Checklist at 3 y in 3209 children. RESULTS: Children of mothers with prenatal folate deficiency were at higher risk of emotional problems (OR: 1.57; 95% CI: 1.03, 2.38) but not behavioral problems (OR: 1.00; 95% CI: 0.64, 1.56) after adjustment for confounders. A higher risk of emotional problems was also found in children whose mothers started using folic acid supplements late or did not use supplements at all (OR: 1.45; 95% CI: 1.14, 1.84) than in children whose mothers started periconceptionally. However, low plasma folate concentrations only partly explained this association (OR: 1.38; 95% CI: 1.08, 1.78). Although related to plasma folate concentrations, maternal MTHFR genotype did not explain the association of folate status with offspring emotional problems. CONCLUSION: Low maternal folate status during early pregnancy is associated with a higher risk of emotional problems in the offspring.

Infant brain development and vulnerability to later internalizing difficulties: the Generation R study.

OBJECTIVE: Although clinical studies have demonstrated smaller subcortical volumes in structures such as the amygdala, hippocampus, caudate nucleus, and thalamus in adults and adolescents with depressive disorders and anxiety, no study has assessed such structures in babies, long before the development of the disorders. This study examined whether the size of the "gangliothalamic ovoid" (encompassing the basal ganglia and thalamus) assessed during infancy is associated with increased internalizing problems in early childhood. METHOD: Cranial ultrasounds were used to assess gangliothalamic ovoid diameter and ventricular volume at 6 weeks of postnatal age; moreover, head circumference was measured. Outcome data included ratings of internalizing and externalizing problems using the Child Behavior Checklist (reported by mothers and fathers) at 18 and/or 36 months. Analyses were based on a total of 651 children. RESULTS: Smaller gangliothalamic diameter was associated with higher Child Behavior Checklist Internalizing scores at ages 18 and 36 months. Results remained significant after correcting for head circumference and were evident for the DSM-oriented subscales of anxiety problems and affective problems. Total ventricular volume was not consistently associated with Internalizing scores. CONCLUSIONS: Findings associating infant brain measurements with Child Behavior Checklist mother and father reports at two time points are consistent with previous cross-sectional reports of smaller subcortical volumes in depression. Results were not simply reflective of overall brain development, because the pattern held after adjustment for head circumference. This is the first study to point toward a biological vulnerability evident in infancy, involved in the development of internalizing problems in childhood.

Maternal folic acid supplement use in early pregnancy and child behavioural problems: The Generation R Study.

Folate deficiency during embryogenesis is an established risk factor for neural tube defects in the fetus. An adequate folate nutritional status is also important for normal fetal growth and brain development. The aim of the present research was to study the association between folic acid use of the mother during pregnancy and child behavioural development. Within a population-based cohort, we prospectively assessed folic acid supplement use during the first trimester by questionnaire. Child behavioural and emotional problems were assessed with the Child Behaviour Checklist at the age of 18 months in 4214 toddlers. Results showed that children of mothers who did not use folic acid supplements in the first trimester had a higher risk of total problems (OR 1.44; 95 % CI 1.12, 1.86). Folic acid supplement use protected both from internalising (OR of no supplement use 1.65; 95 % CI 1.24, 2.19) and externalising problems (OR 1.45; 95 % CI 1.17, 1.80), even when adjusted for maternal characteristics. Birth weight and size of the fetal head did not mediate the association between folic acid use and child behaviour. In conclusion, inadequate use of folic acid supplements during early pregnancy may be associated with a higher risk of behavioural problems in the offspring. Folic acid supplementation in early pregnancy, aimed to prevent neural tube defects, may also reduce mental health problems in children.