During pregnancy, most doctors advise women to stay away from such things as alcohol, coffee, and certain medicines. For example, pregnant women are advised to avoid antidepressants, because studies have shown antidepressants can cause neurodevelopmental problems such as autism spectrum disorder, and attention-deficit/hyperactivity disorders as well as complications like shorter gestation, reduced fetal growth. Obvious concerns include the economic and social stress placed on a family and the child. Shorter gestation is associated with limited body and organ growth and decreased oxygen access. Reduced fetal growth is associated with the development of cardiovascular disease, stroke, and eventually, death. However, according to a study led by Dr. Ayesha Sujan, Dr. Brian D’Onofrio, and Dr. Sara Oberg, some of these outcomes may have been exaggerated. “Observing an association between antidepressant use and adverse outcomes in the offspring does not have to mean that antidepressant use is causing the outcome,” Dr. Oberg said.
In this recent study, scientists examined a little more than 1.5 million Swedish children to examine the association between first-trimester antidepressant exposure and the risk of preterm birth, small size for gestational age, autism spectrum disorder, and attention-deficit/hyperactivity disorders. “This was made possible by linkage of nation-wide population registers through which individuals could be followed,” says Dr. Oberg. In analyzing this data, the scientists used several approaches to explore non-causal explanations to the observed associations. “Antidepressant use can appear associated with an adverse outcome if the two share risk factors, and this we call confounding. The aim of this study was to use different designs to understand the role of confounding, both measured and unmeasured,” Dr. Oberg said. Some of the reasons for using antidepressants in pregnancy, such as severity of symptoms or stress, may also influence risk of pregnancy complications or neurodevelopmental problems in the offspring.
The results seem to show an association between antidepressant use and adverse effects after birth. However, once the data was adjusted for factors such as measured pregnancy, maternal and paternal traits, and timing of exposure to antidepressants, the associations were less pronounced. The researchers then compared exposed children to their unexposed siblings, thereby additionally accounting for all factors that siblings share. In this analysis, maternal first trimester antidepressant use was still associated with preterm birth, but no association was seen with small for gestational age. The hazard ratio, the probability of children developing a disorder, comparing exposed children to unexposed children for autism spectrum disorder was about 0.83 and about 0.99 for attention-deficit/hyperactivity disorder. From these results, the scientists conclude that there is a small risk of preterm birth associated with maternal first trimester antidepressant use. Otherwise, there does not appear to be any risk for children being small for gestational age or developing disorders like autism spectrum disorder and attention-deficit/hyperactivity disorders.
Despite these favorable results, Dr. Oberg still advises caution. “While providing some reassuring news regarding the risk of short gestational age, autism spectrum disorder, and ADHD following antidepressant use early in pregnancy, this does not mean we can go ahead and say that it is safe for women to take antidepressants in pregnancy,” said Dr. Oberg. More research needs to be conducted to understand the role of timing and especially late trimester exposure to antidepressants. “It is also vital to fully understand the influence of the underlying depression and severity of symptoms so that women with depression can receive appropriate care in pregnancy,” said Dr. Oberg. In this pursuit, Dr. Oberg and team have taken the first steps towards breaking the myth of antidepressant use.