A new study has found that women with higher levels of autistic traits are more likely to have adverse birth outcomes, such as preterm births and children born small for gestational age (SGA). The study, published in JAMA Network Open, is the first to examine the association between maternal autistic traits and the risk for adverse birth outcomes in a large, nationwide, multicenter prospective birth cohort.
What are autistic traits and how are they measured?
Autistic traits are characteristics that reflect the cognitive, behavioral, and social aspects of autism spectrum disorder (ASD), a developmental condition that affects how people communicate and interact with others. Autistic traits can vary widely among individuals and are not necessarily indicative of a clinical diagnosis of ASD. However, some people may have a high level of autistic traits that affect their daily functioning and quality of life.
Autistic traits can be measured using various tools, such as the Autism-Spectrum Quotient (AQ), a self-report questionnaire that assesses the degree of autistic-like features in adults. The AQ consists of 50 items that cover five domains: social skills, attention switching, attention to detail, communication, and imagination. A higher AQ score indicates a higher level of autistic traits.
The study used the short form of the AQ Japanese version (AQ-J10), which consists of 10 items that are derived from the original AQ. The AQ-J10 has been validated in the Japanese population and has shown good reliability and validity. The AQ-J10 score ranges from 0 to 10, with a higher score indicating a higher level of autistic traits. A score of 6 or higher is considered to be within the clinical range, meaning that the person may have a high probability of having ASD.
What did the study find?
The study included 87,687 women who gave birth to singletons between 2011 and 2014 in Japan. The women completed the AQ-J10 during the second and third trimesters of pregnancy. The study also collected information on maternal and pregnancy-related factors, such as age, education, income, smoking, alcohol use, body mass index, parity, gestational diabetes, hypertension, and depression. The study defined adverse birth outcomes as preterm births (before 37 weeks of gestation), moderate-to-late preterm births (32 to 36 weeks of gestation), very preterm births (before 32 weeks of gestation), and SGA (birth weight below the 10th percentile for gestational age).
The study found that 2.7% of the women had AQ-J10 scores within the clinical range, and 0.02% were diagnosed with ASD. The study also found that a higher AQ-J10 score was associated with an increased risk for all birth outcomes, after adjusting for maternal and pregnancy-related factors. Specifically, the study found that:
- For every one-standard deviation increase in the AQ-J10 score (about 1.5 points), the risk for preterm births increased by 6%, the risk for moderate-to-late preterm births increased by 5%, the risk for very preterm births increased by 16%, and the risk for SGA increased by 4%.
- Women with AQ-J10 scores within the clinical range had 16% higher risk for preterm births, 12% higher risk for moderate-to-late preterm births, 49% higher risk for very preterm births, and 11% higher risk for SGA, compared to women with AQ-J10 scores below the clinical range.
The study also conducted subgroup analyses to examine the effect of maternal autistic traits on birth outcomes by maternal age, parity, and depression. The study found that the association between maternal autistic traits and adverse birth outcomes was stronger among older women, multiparous women, and women with depression.
What are the possible explanations and implications of the study?
The study authors suggested several possible mechanisms that may explain how maternal autistic traits may affect pregnancy outcomes. For example, women with higher levels of autistic traits may have more difficulties in accessing and utilizing prenatal care, coping with stress, and adhering to healthy behaviors during pregnancy. Moreover, women with higher levels of autistic traits may have more specific dietary patterns that lack certain nutrients required during pregnancy, potentially leading to fetal growth restriction and a heightened risk of preterm birth.
The study authors also highlighted the clinical and public health implications of their findings. They emphasized that health care practitioners should acknowledge the significant perinatal health disparity experienced by women with a high level of autistic traits, particularly those with autistic traits in the clinical range. They recommended that women with higher levels of autistic traits should be screened for pregnancy complications and offered tailored interventions to optimize their pregnancy outcomes. They also suggested that women with higher levels of autistic traits should be provided with adequate support and resources to enhance their well-being and parenting skills.
The study authors acknowledged some limitations of their study, such as the use of self-reported data, the lack of information on paternal autistic traits, and the potential residual confounding by unmeasured factors. They also noted that their findings may not be generalizable to other populations or settings. They called for more research to replicate and extend their findings, and to explore the biological and psychosocial pathways that link maternal autistic traits and adverse birth outcomes.