Diagnosing maternal anemia early in pregnancy may be associated with increased risk for autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and intellectual disability (ID) in the child, according to research published in JAMA Psychiatry.

Iron deficiency and iron deficiency anemia are common during pregnancy. However, the association between maternal iron shortage and the offspring’s risk for neurodevelopmental disorders is unclear.

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Researchers conducted a prospective registry-based cohort study to evaluate 532,232 non-adopted children and their 299,768 mothers. Mothers were diagnosed with anemia in 31,018 pregnancies. Of mothers diagnosed with anemia, 1534 (5%) were diagnosed before 30 weeks of pregnancy and 28,198 (90.9%) were diagnosed after 30 weeks of pregnancy.

Mothers who were overweight (odds ratio [OR], 1.16; 95% CI, 1.12-1.19) and obese (OR, 1.28; 95% CI, 1.22-1.34) or older than than 40 years (OR, 1.17; 95% CI, 1.10-1.25) were more likely to be diagnosed with anemia compared with normal-weight mothers and mothers younger than 25 years, respectively. Other factors associated with increased incidence of maternal anemia included psychiatric history, being in the highest income quintile, primipara, interpregnancy interval longer than 5 years, multiple births, and hospitalization for infection during pregnancy.

Earlier onset anemia (occurring before 30 weeks of pregnancy) was more common in less educated parents, less wealthy families, underweight mothers, and younger mothers.

Children born to mothers diagnosed with anemia before 30 weeks of pregnancy were more likely to be born preterm or small for gestational age compared with children whose mothers were not diagnosed with anemia. Conversely, children born to mothers diagnosed with anemia after 30 weeks of gestation were more likely to be born post-term and large for gestational age.

Risk for ASD was associated with both earlier and later diagnosis of anemia, whereas risk for ADHD and ID was increased only in children born to mothers with an early diagnosis. The strongest mediator for obstetric complications was preterm delivery, which accounted for approximately one-third of the association between early diagnosis of anemia and risk for ASD, ADHD, or ID.

The investigators noted that earlier diagnosis of maternal anemia was associated with greater risk for ASD, ADHD, and ID even in models considering potential confounds, such as socioeconomic, maternal, and pregnancy-related factors. They underscored the value of screening pregnant patients for iron status and nutritional counseling.

Reference

  1. Wiegersma AM, Dalman C, Lee BK, et al. Association of prenatal maternal anemia with neurodevelopmental disorders [published online September 18, 2019]. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2019.2309