Paracetamol during pregnancy: a link with childhood depression?

A University of Auckland study shows a “small but significant” statistical association.

Professor Karen Waldie and her colleagues analysed data from Growing Up in New Zealand, the nation’s biggest longitudinal study, relating to 3,925 eight-year-olds and their mothers.

“Women shouldn’t be alarmed, but mounting evidence suggests it may be wise to use as low a dose of paracetamol as possible for the shortest time possible during pregnancy,” says Professor Waldie, of the School of Psychology in the Faculty of Science.

The researchers mined data from the Growing Up study to look for statistical associations between the health and lifestyles of women during pregnancy and the later incidence of signs of depression in children.

Read Prenatal determinants of depressive symptoms in childhood: Evidence from Growing Up in New Zealand Study in the National Library of Medicine.

The data came from quizzing mothers during pregnancy and, eight years later, quizzing children on such signs of depression as low mood, loss of appetite, and sleep disturbance. (Most mothers took paracetamol.)

Using statistical methods to analyse the information, the researchers found four lifestyle and health factors during pregnancy that seemed to be predictive of later signs of depression in kids. These were:

• Paracetamol use (also including Panadol, which contains acetaminophene)
• Being obese or overweight
• Smoking
• Stress

Individually, alcohol consumption, antidepressant use and smoking patterns were positively associated with childhood depressive symptoms (and folate and multivitamin use were protective). However, in the researchers’ final statistical model, which accounted for a range of variables, those factors didn’t remain statistically significant.

The study feeds into research around the world on how exposure to certain nutrients and chemicals during pregnancy may affect how children develop. This “fetal programming” could work partly by affecting the expression and function of genes.

In September last year, a group of international scientists urged caution around paracetamol during pregnancy, citing epidemiological studies and experimental research suggesting exposure could alter fetal development, increasing the risk of neurodevelopmental, reproductive, and urogenital disorders.

Epidemiological studies have shown statistical associations between paracetomol and attention deficit hyperactivity disorder (ADHD), autism spectrum disorder, language delay in girls and decreased intelligence quotients.

However, nothing is proven. In addition, there are limited alternatives to one of the world’s most popular drugs for treating pain and fever, and risks to mother and baby if pain or fever are left unchecked.

“We recognise that limited medical alternatives exist to treat pain and fever,” the international scientists said in the journal Nature Reviews Endocrinology. However, “the combined weight of animal and human scientific evidence is strong enough for pregnant women to be cautioned by health professionals against its indiscriminate use, both as a single ingredient and in combination with other medications.”

Professor Waldie says she supports that statement.

A previous University of Auckland study strengthened the case that taking paracetamol during pregnancy may increase the risk of ADHD-like behaviours in children.

The more recent research is the first that the University of Auckland academics are aware of to point to a potential link between paracetamol and childhood depression.

The prevalence of depression in young people has increased rapidly over the past decade, Professor Waldie and her colleagues wrote in the research paper. “Existing research from the United States indicates that depression affects around one percent of pre-schoolers and two percent of children.”

Young people who experience depression are at an increased risk of dependence on alcohol, suicidality, and impaired academic performance, the academics say.

Honours student Gisela Theunissen was the lead author of the paper.