Age at Autism Spectrum Disorder (ASD) Diagnosis by Race, Ethnicity, and Primary Household Language Among Children with Special Health Care Needs, United States, 2009-2010.

We examined prevalence of diagnosed autism spectrum disorder (ASD) and age at diagnosis according to child's race/ethnicity and primary household language. From the 2009-2010 National Survey of Children with Special Health Care Needs, we identified 2729 3-17-year-old US children whose parent reported a current ASD diagnosis. We compared ASD prevalence, mean diagnosis age, and percentage with later diagnoses (≥5 years) across racial/ethnic/primary household language groups: non-Hispanic-white, any language (NHW); non-Hispanic-black, any language (NHB); Hispanic-any-race, English (Hispanic-English); and Hispanic-any-race, other language (Hispanic-Other). We assessed findings by parent-reported ASD severity level and adjusted for family sociodemographics. ASD prevalence estimates were 15.3 (NHW), 10.4 (NHB), 14.1 (Hispanic-English), and 5.2 (Hispanic-Other) per 1000 children. Mean diagnosis age was comparable across racial/ethnic/language groups for 3-4-year-olds. For 5-17-year-olds, diagnosis age varied by race/ethnicity/language and also by ASD severity. In this group, NHW children with mild/moderate ASD had a significantly higher proportion (50.8 %) of later diagnoses than NHB (33.5 %) or Hispanic-Other children (18.0 %). However, NHW children with severe ASD had a comparable or lower (albeit non-significant) proportion (16.4 %) of later diagnoses than NHB (37.8 %), Hispanic-English (30.8 %), and Hispanic-Other children (12.0 %). While NHW children have comparable ASD prevalence and diagnosis age distributions as Hispanic-English children, they have both higher prevalence and proportion of later diagnoses than NHB and Hispanic-Other children. The diagnosis age findings were limited to mild/moderate cases only. Thus, the prevalence disparity might be primarily driven by under-representation (potentially under-identification) of older children with mild/moderate ASD in the two minority groups.

Gestational diabetes mellitus, prenatal air pollution exposure, and autism spectrum disorder.

BACKGROUND: Ambient air pollution and maternal diabetes may affect common biological pathways underlying adverse neurodevelopmental effects. However, joint effects of maternal diabetes and air pollution on autism spectrum disorder (ASD) have not been studied. OBJECTIVE: We evaluated whether prenatal and early-life air pollution exposure interacts with maternal diabetes status to affect ASD risk. METHODS: This retrospective cohort study included 246,420 singleton children born in Kaiser Permanente Southern California hospitals in 1999-2009. Children were followed from birth until age 5, during which 2471 ASD cases were diagnosed. Ozone (O3), particulate matter < 2.5 µm (PM2.5) and <10 µm in aerodynamic diameter, and nitrogen dioxide measured at regulatory air monitoring stations were interpolated to estimate exposures during preconception and each pregnancy trimester, and first year of life at each child's birth address. Hazard ratios (HRs) for ASD were estimated adjusting for birth year, KPSC service areas, and relevant maternal and child characteristics. For each exposure window, interactions were tested between pollutants and a 4-category maternal diabetes variable (none, GDM ≥ 24 and <24 weeks' gestation, and pre-existing type 2 diabetes). For an exposure window with statistically significant global interaction between pollutant and diabetes (p < 0.05), pollutant-associated HRs were estimated separately for each category of maternal diabetes. RESULTS: There were associations of ASD with preconception, first and third trimesters, and first year of life PM2.5, but not with other pollutants. There were, however, interactions of maternal diabetes with first trimester and first year of life O3. Increased ASD risk was associated with first trimester O3 among mothers with GDM < 24 weeks' gestation [adjusted HR 1.50 per 15.7 ppb O3 (95% CI: 1.08-2.09)]. No O3 associations with ASD were observed in other categories of maternal diabetes. CONCLUSIONS: GDM onset early in pregnancy may increase children's susceptibility to prenatal O3-associated ASD risk. These novel findings merit further investigation.

Associations of gestational diabetes mellitus with residential air pollution exposure in a large Southern California pregnancy cohort.

BACKGROUND: Studies of effects of air pollution on gestational diabetes mellitus (GDM) have not been consistent, and there has been little investigation of effects of exposure preceding pregnancy. In previous studies, the temporal relationship between exposure and GDM onset has been difficult to establish. METHODS: Data were obtained for 239,574 pregnancies between 1999 and 2009 in a population-based health care system with comprehensive electronic medical records. Concentrations of ambient nitrogen dioxide (NO2), particulate matter (PM) ≤2.5 µm in aerodynamic diameter (PM2.5) and ≤10 µm (PM10), and ozone (O3) during preconception and the first trimester of pregnancy at the residential birth address were estimated from regulatory air monitoring stations. Odds ratios (ORs) of GDM diagnosed in the second and third trimesters in association with pollutant exposure were estimated using generalized estimating equation models adjusted for birth year, medical center service areas, maternal age, race/ethnicity, education, census-tract household income, and parity. RESULTS: In single-pollutant models, preconception NO2 was associated with increased risk of GDM (OR = 1.10 per 10.4 ppb, 95% confidence interval [CI]: 1.07, 1.13). First trimester NO2 was weakly associated with GDM, and this was not statistically significant (OR = 1.02 per 10.4 ppb, 95% CI: 0.99, 1.05). Preconception NO2 associations were robust in multi-pollutant models adjusted for first trimester NO2 with another co-pollutant from both exposure windows. In single-pollutant models, preconception PM2.5 and PM10 associations were associated with increased risk of GDM (OR = 1.04 per 6.5 µg/m3, 95% CI: 1.01, 1.06; OR = 1.03 per 16.1 µg/m3, 95% CI: 1.00, 1.06, respectively), but these effect estimates were not robust to adjustment for other pollutants. In single-pollutant models, preconception and first trimester O3 were associated with reduced risk of GDM (OR = 0.94 per 15.7 ppb, 95% CI: 0.92, 0.95; OR = 0.95 per 15.7 ppb, 95% CI: 0.94, 0.97), associations that were robust to adjustment for co-pollutants. CONCLUSIONS: Maternal exposure to NO2 during the preconception trimester may increase risk of GDM.

Sex-specific associations of autism spectrum disorder with residential air pollution exposure in a large Southern California pregnancy cohort.

Autism spectrum disorder (ASD) affects more boys than girls. Recent animal studies found that early life exposure to ambient particles caused autism-like behaviors only in males. However, there has been little study of sex-specificity of effects on ASD in humans. We evaluated ASD risk associated with prenatal and first year of life exposures to particulate matter less than 2.5 µm in aerodynamic diameter (PM2.5) by child sex. This retrospective cohort study included 246,420 singleton children born in Kaiser Permanente Southern California (KPSC) hospitals between 1999 and 2009. The cohort was followed from birth through age five to identify 2471 ASD cases from the electronic medical record. Ambient PM2.5 and other regional air pollution measurements (PM less than 10 µm, ozone, nitrogen dioxide) from regulatory air monitoring stations were interpolated to estimate exposure during each trimester and first year of life at each geocoded birth address. Hazard ratios (HRs) were estimated using Cox regression models to adjust for birth year, KPSC medical center service areas, and relevant maternal and child characteristics. Adjusted HRs per 6.5 µg/m3 PM2.5 were elevated during entire pregnancy [1.17 (95% confidence interval (CI), 1.04-1.33)]; first trimester [1.10 (95% CI, 1.02-1.19)]; third trimester [1.08 (1.00-1.18)]; and first year of life [1.21 (95% CI, 1.05-1.40)]. Only the first trimester association remained robust to adjustment for other exposure windows, and was specific to boys only (HR = 1.18; 95% CI, 1.08-1.27); there was no association in girls (HR = 0.90; 95% CI, 0.76-1.07; interaction p-value 0.03). There were no statistically significant associations with other pollutants. PM2.5-associated ASD risk was stronger in boys, consistent with findings from recent animal studies. Further studies are needed to better understand these sexually dimorphic neurodevelopmental associations.

Maternal prepregnancy body mass index and child psychosocial development at 6 years of age.

BACKGROUND: Both obesity and developmental disabilities have increased in recent decades. Limited studies suggest associations between maternal prepregnancy obesity and child neurodevelopment. METHODS: The Infant Feeding Practices Study II, a US nationally distributed longitudinal study of maternal health and infant health and feeding practices, was conducted from 2005 to 2007. In 2012, mothers were recontacted for information on their children's health and development. We examined associations between maternal prepregnancy BMI and child psychosocial development in 1311 mother-child pairs included in this follow-up study. Children's development was assessed by maternal report of child psychosocial difficulties from the Strengths and Difficulties Questionnaire, past developmental diagnoses, and receipt of special needs services. RESULTS: Adjusting for sociodemographic factors, children of obese class II/III mothers (BMI >35.0) had increased odds of emotional symptoms (adjusted odds ratio [aOR] 2.24; 95% confidence interval [CI], 1.27-3.98), peer problems (aOR 2.07; 95% CI, 1.26-3.40), total psychosocial difficulties (aOR 2.17; 95% CI, 1.24-3.77), attention-deficit/hyperactivity disorder diagnosis (aOR 4.55; 95% CI, 1.80-11.46), autism or developmental delay diagnosis (aOR 3.13; 95% CI, 1.10-8.94), receipt of speech language therapy (aOR 1.93; 95% CI, 1.18-3.15), receipt of psychological services (aOR 2.27; 95% CI, 1.09-4.73), and receipt of any special needs service (aOR 1.99; 95% CI, 1.33-2.97) compared with children of normal weight mothers (BMI 18.5-24.9). Adjustment for potential causal pathway factors including pregnancy weight gain, gestational diabetes, breastfeeding duration, postpartum depression, and child's birth weight did not substantially affect most estimates. CONCLUSIONS: Children whose mothers were severely obese before pregnancy had increased risk for adverse developmental outcomes.