Autistic Traits in Mothers Linked to Increased Risk of Preterm Birth

Multiple barriers to receiving adequate prenatal care, including communication difficulties and lack of tailored resources, may lead to an increased risk of preterm birth in mothers who score higher on autism quotient tests.

Autism spectrum disorder (ASD) includes a wide range of symptoms that can impact a person's daily life at varying levels. However, autistic traits, including difficulty understanding social cues, communication challenges, and strict adherence to routines, can occur in people without ASD.

Some research suggests that autistic traits are common in the general public, and autism exists on a continuum in the general population.

However, other studies question that hypothesis.

While much is already known about how autism impacts employment, romantic relationships, and education, it's unclear whether people with autistic traits experience similar challenges. Moreover, few studies have examined whether autism or autistic traits affect other aspects of life, like birth outcomes.

In a first-of-its-kind study, researchers wanted to clarify this better, so they took a closer look at whether high levels of autistic traits in mothers could lead to adverse birth outcomes, such as preterm birth or babies born small for gestational age (SGA).

The study, published on January 23 in JAMA Network Open, included 87,000 female participants recruited between January 2011 and March 2014 by the Japan Environmental Children's Study — a nationwide, multicenter, prospective birth cohort study funded by the Ministry of the Environment of Japan.

The team measured maternal autistic traits during the participants' second or third trimesters using the AQ-J10 — a questionnaire designed to identify autistic traits in the general population.

Then, using medical records, the scientists assessed the participants' birth outcomes, such as whether they experienced moderate to late preterm birth, very preterm birth, or had a baby born SGA.

When analyzing the data, the team included variables that might impact the results, such as maternal age, highest level of education, and preexisting health conditions.

Overall, participants in the general population who had higher levels of autistic traits had an increased risk of all adverse birth outcomes, including preterm, moderate-to-late preterm, very preterm births, and a child born SGA.

Moreover, every standard deviation increase in maternal autistic traits was associated with a 1.16-fold increased risk of very preterm birth after adjusting for variables and pregnancy complications.

The scientists note that 2,350 participants had AQ-J10 scores within the clinical range for an autism diagnosis, yet only 18 were diagnosed with ASD.

Why would autistic traits be a risk factor for preterm birth?

The study's authors suggest there could be several reasons for the findings. For example, previous research found that women with developmental and intellectual disabilities, including autism, were more likely to begin prenatal care later and experience multiple barriers to care.

In addition, communication challenges and a lack of resources tailored to autistic individuals or people with autistic traits may play a role in the findings.

The scientists say previous research has shown that women with a higher level 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. Women with higher levels of autistic traits may also experience more psychological distress during pregnancy, which is linked to poorer birth outcomes.

Although the study did not prove that a higher level of autistic traits in women causes adverse pregnancy outcomes, the findings shine a light on the need for more personalized and timely prenatal care and support for individuals with these traits, even if they do not have a formal ASD diagnosis.