Parental asthma and risk of autism spectrum disorder in offspring: a population and family-based case-control study
Children of mothers with asthma are at increased risk of developing autism, highlighting the importance of studying environmental risk factors during pregnancy.
Gong T, Lundholm C, Rejno G, et al. Clinical and Experimental Allergy. 2019 Feb 11.
This large observational study reports that children of mothers with asthma are at increased risk of developing autism spectrum disorder (ASD). The study looked at all children born in Sweden between 1992 and 2007, including almost 23,000 children with ASD. The researchers posit that maternal immune activation during pregnancy may represent a biological mechanism explaining the association. The increased ASD risk could not be explained by socioeconomic, demographic, or genetic factors, underscoring “the importance of investigating other maternal environmental factors.”
A lowered probability of pregnancy in females in the USA aged 25–29 who received a human papillomavirus vaccine injection
Women vaccinated for HPV have a lower probability of conceiving.
Gayle DeLong (2018) Journal of Toxicology and Environmental Health, Part A, 81:14, 661-674, DOI: 10.1080/15287394.2018.1477640
Approximately 60% of the single women who did not receive the HPV vaccine had been pregnant at least once, whereas only 35% of women who were exposed to the vaccine had conceived. For married women, 75% who did not receive the shot were found to conceive, while only 50% who received the vaccine had ever been pregnant.
The offspring of mothers exposed to DDT and its metabolites during pregnancy are at increased risk for autism.
Brown AS, Cheslack-Postava K, Rantakokko P, et al. American Journal of Psychiatry. 2018;175:1094-1101.
The study provides the first evidence based on biomarkers of an increased autism risk in the offspring of mothers exposed to certain insecticides during pregnancy. In this large national birth cohort study of Finnish children, the odds of autism plus intellectual disability were increased by greater than twofold in mothers measuring with the highest levels of a DDT metabolite.
Prenatal stress, maternal immune dysregulation, and their association with autism spectrum disorders
Two prenatal exposures—stress and maternal immune dysregulation—are associated with autism, probably in combination with other genetic and environmental risk factors.
Beversdorf DQ, Stevens HE, Jones KL. Current Psychiatry Reports. 2018;20:76.
Prenatal stress and disruption of a pregnant woman’s immune response (“maternal immune activation”) are two environmental factors associated with the increased incidence of autism spectrum disorder (ASD). However, the fact that, in many cases, these prenatal exposures do not result in ASD suggests an “interaction with multiple other risks.” Some evidence points to greater susceptibility to prenatal stress and maternal immune dysregulation in male offspring.
In utero exposure to methylmercury from power plants and seafood is associated with lifelong loss of intelligence and billions of dollars in lost productivity.
Trasande L, Landrigan PJ, Schechter C. Public health and economic consequences of methyl mercury toxicity to the developing brain. Environmental Health Perspectives. 2005;113(5):590-596.
This study shows that the IQ losses associated with methylmercury toxicity cost the U.S. economy billions of dollars in lost productivity each year. Hundreds of thousands of American children in any given year have cord blood levels of methylmercury associated with lowered intelligence, traceable to in utero exposure to power plant emissions or to maternal seafood consumption. The loss of intelligence that results “causes diminished economic productivity that persists over the entire lifetime of these children”—amounting to about $8.7 billion annually.