Does breastfeeding account for the association between maternal sensitivity and infant cognitive development in a large, nationally representative cohort?

BACKGROUND: Previous research has established that exposure to high maternal sensitivity is positively associated with advances in infant cognitive development. However, there are many fixed and modifiable factors that influence this association. This study investigates whether the association between maternal sensitivity and infant cognitive development in the first year of life is accounted for by other factors, such as breastfeeding, maternal depressive symptoms, maternal alcohol use, infant birth weight or demographic covariates. METHODS: Using data from the Early Childhood Longitudinal Study-Birth (ECLS-B) Cohort, a nationally representative sample of U.S. born children, multi-variable regression analyses was used to examine whether breastfeeding, maternal depressive symptoms and alcohol use were associated with maternal sensitivity, as measured by the Nursing Child Assessment Teaching Scale (NCATS), and with infant cognitive development, as measured by the Bayley Scales of Infant Development, Short Form, Research Edition, after controlling for demographic covariates (infant sex, maternal age, education, race/ethnicity, income, parity, family structure) and infant birth weight. RESULTS: Breastfeeding, depressive symptoms and alcohol use were not associated with maternal sensitivity scores after controlling for demographic covariates and infant birth weight. However, breastfeeding (ß = .079, p < .001), depressive symptoms (ß = -.035, p < .05), and maternal sensitivity (ß = .175, p < .001) were each significantly associated with infant cognitive development scores, even after controlling for demographic covariates and birthweight (R2 = .053, p < .001). The association between maternal sensitivity and infant cognitive development did not attenuate after adjusting for breastfeeding. Instead, both sensitivity and breastfeeding independently contributed to higher infant cognitive development scores. CONCLUSION: Maternal sensitivity and breastfeeding are separate means to advancing infant cognitive development. This study is significant because it is the first to examine breastfeeding, maternal depressive symptoms and alcohol use together, upon the association between maternal sensitivity and infant cognitive development, after adjusting for demographic covariates and infant birthweight. Maternal sensitivity, a measurable quality, advances infants' cognitive development. Moreover, sensitivity and breastfeeding had independent effects upon cognitive development after controlling for multiple fixed and modifiable covariates. Understanding factors impacting the association between sensitivity and infant cognitive development provide avenues for developing more effective parenting interventions.

The incidence of diagnosed autism spectrum disorders in Finland.

BACKGROUND: Previous reports indicate an increase in incidence of autism spectrum disorders (ASD). AIMS: First, to assess the incidence of diagnosed ASD in children born between 1996 and 1998, based on nationwide inpatient and outpatient register information. Second, to investigate the incidence rate over time of diagnosed ASD and specifically childhood autism, Asperger's syndrome and pervasive developmental disorder (PDD-NOS) in children born between 1987 and 1998. METHODS: This is population-based cohort study with children born in Finland between 1 January 1987 and 31 December 2005; a total of more than 1.2 million children. Children were identified in the Finnish Hospital Discharge Register, and the reported diagnoses were based on the International Statistical Classification of Diseases (ICD-10, ICD-9). RESULTS: The annual incidence rate of diagnosed ASD based on inpatient and outpatient register data was 53.7 per 10,000 (95% CI 50.4-57.2). Incidence was 82.6 per 10,000 in boys and 23.6 per 10,000 in girls, yielding a sex ratio (boys:girls) of 3.5:1. We report an eightfold increase in the incidence rates in children of diagnosed ASD and specifically in childhood autism, Asperger's syndrome and PDD-NOS and born between 1987 and 1992 based on inpatient register information. CONCLUSIONS: Increased awareness of ASD, more precise diagnostic criteria and changes in practice for diagnosing autism may have had a substantial effect on the increased incidence of inpatient treated ASD cases from 1987 to 1992. Between 1992 and 1998, the incidence rate based on inpatient and outpatient service use remained rather stable.

Risk of autism spectrum disorders in low birth weight and small for gestational age infants.

OBJECTIVE: To examine the relationship between birth weight, gestational age, small for gestational age (SGA), and 3 of the most common autism spectrum disorder (ASD) subtypes. STUDY DESIGN: In this population-based case-control study conducted in Finland, 4713 cases born between 1987 and 2005 with International Classification of Diseases-diagnoses of childhood autism, Asperger syndrome, or pervasive developmental disorder (PDD), were ascertained from the Finnish Hospital Discharge Register. Four controls, individually matched on sex, date of birth, and place of birth, were selected from the Finnish Medical Birth Register for each case. Conditional logistic regression models were used to assess whether birth weight and gestational age information predicted ASD after controlling for maternal age, parity, smoking during pregnancy, and psychiatric history, as well as for infant's major congenital anomalies. RESULTS: Very low (<1500 g) and moderately low (<2500 g) birth weight, very low gestational age (less than 32 weeks), and SGA increased risk of childhood autism (adjusted OR 3.05, 95% CI 1.4-6.5; 1.57, 1.1-2.3; 2.51, 1.3-5.0; and 1.72, 1.1-2.6, respectively). Very low and moderately low birth weight, very low gestational age, and SGA were also associated with increase in PDD risk (OR 3.44, 95% CI 1.9-6.3; 1.81, 1.4-2.4; 2.46, 1.4-2.3; and 2.24, 1.7-3.0, respectively). No associations were found between the perinatal characteristics and Asperger syndrome. The increased risks persisted after controlling for selected potential confounders. CONCLUSIONS: The finding that low birth weight, prematurity, and SGA were related to childhood autism and PDD but not to Asperger syndrome suggests that prenatal factors related to these exposures may differ for these ASD subtypes, which may have preventive implications.

Finnish Prenatal Study of Autism and Autism Spectrum Disorders (FIPS-A): overview and design.

This article presents an overview of the Finnish Prenatal Study of Autism and Autism Spectrum Disorders (FIPS-A), a new study designed to examine the relationship between prenatal serologic factors, mediating and moderating developmental antecedents, and risk of autism spectrum disorders (ASD). The FIPS-A is based on register linkages between births from 1987 to 2005 ascertained from the Finnish Medical Birth Register (FMBR) and other national registers on treatment for this group of disorders. All subjects were members of the Finnish Maternity Cohort (FMC), which consists of virtually all births in Finland from 1983 to the present, and which includes archived maternal serum samples. This study also capitalizes on other registry information, such as systematically collected data on pregnancy, prenatal and neonatal complications and manual data collection from well-child clinics providing developmental data from birth to the age of 7 years. In this paper, we describe the methods used in the FIPS-A study, including a description of the national registers, available data and case ascertainment procedures. Finally, we discuss implications of the data for future work on uncovering putative aetiologies of ASD and key strengths and limitations of the design.