LONDON, Jan 4: Anti-inflammatory drugs, commonly used by millions of pregnant women worldwide, may increase the risk of autism in their babies, according to a new study.

The research focused on the effects of glucocorticoids, a class of steroids, on children who were exposed to these drugs in the womb. It found that babies exposed to glucocorticoids had a 30 to 50 percent higher chance of being diagnosed with autism compared to those whose mothers did not take the drugs.

The study also linked glucocorticoid exposure to an increased risk of intellectual disabilities, Attention-deficit/hyperactivity disorder (ADHD), and anxiety in children. Glucocorticoids, which include medications like prednisone and cortisone, mimic the hormone cortisol, produced by the adrenal gland, known for its anti-inflammatory effects.

These steroids are often prescribed to pregnant women at risk of preterm birth because they assist in fetal organ development and maturation. Additionally, they are used to treat pregnant women with autoimmune or inflammatory conditions, such as rheumatoid arthritis, lupus, and asthma, as they help suppress the immune response.

However, the study suggests that excessive exposure to glucocorticoids during pregnancy may negatively impact brain development in the fetus. It is estimated that two to three percent of the population are currently prescribed glucocorticoids, with the most common drugs in the US being prednisone, triamcinolone acetonide, and methylprednisolone.

Betamethasone and dexamethasone, which can cross the placenta, are typically used for women at risk of preterm delivery and are usually administered through injections. While side effects from long-term glucocorticoid use, such as weight gain and osteoporosis, have been known for decades, the latest research from Denmark suggests these drugs could also harm the developing brain of babies.

The study examined the development of more than 1 million infants born between 1996 and 2016, with over 300,000 of them exposed to glucocorticoids in the womb. Some of the women in the study received steroids to prevent preterm birth, while most were treated for autoimmune or inflammatory conditions.

Researchers followed the children for 15 years, reviewing their medical histories to determine how prenatal glucocorticoid exposure affected their development. The findings revealed that children born to mothers at risk of preterm birth who took glucocorticoids were 50 percent more likely to be diagnosed with autism compared to those whose mothers were not exposed to the drugs. The risk of intellectual disabilities and ADHD was 30 percent higher in the exposed group, and the likelihood of developing mood, anxiety, and stress-related disorders was 50 percent higher.

For children of mothers with autoimmune or inflammatory conditions, the study found a 30 percent higher risk of autism and ADHD in the exposed group. Additionally, the risk of mood disorders and intellectual disabilities was 40 percent higher.

The researchers conclude that their data supports "continued caution" in the use of glucocorticoids during pregnancy. They suggest that alternative medications might be safer for pregnant women with autoimmune or inflammatory conditions, though they emphasize the need for further research to evaluate these options.