Approximately 3% – 10% of pregnant women take an antidepressant. According to new research, taking these drugs during the second and third trimester of pregnancy, especially the selective inhibitors of serotonin reuptake (SSRI), like Prozac, almost double the risk of having a child with autism spectrum disorder (ASD).
A group of experts from the University of Montreal (Quebec, Canada) in an article in this week’s issued of JAMA Pediatrics. As the authors note in their work, it is known that exposure to these drugs is associated with higher probabilities of abortion, birth defects, gestational hypertension, prematurity and low birth weight. However, regarding the risk of autism, few studies have gone into this relationship. Some determine an increase in the chances of having a child with autism spectrum disorder, and others, however, suggest that no statistically significant association. In addition, most of these investigations have significant limitations, such as the failure to take into account the genetic predisposition.
Since the expectation is that depression will be the second leading cause of disability worldwide and, therefore, antidepressants will continue to be used, even in pregnancy is a public health priority to have more information on effects long term neurological development of children when used during pregnancy.
The team of researchers decided to analyze the cases of all pregnancies and babies born in Quebec between January 1998 and 2009, from the moment of conception until ten. Of the 145,456 new lives, 1,054 were diagnosed with ASD, representing 0.72%. This is one, even lower than recent estimates, which place it at around 1% moderate prevalence.
Of the 145,456 births, 4,724 were exposed to antidepressants in utero; the rest (140 732), no. Of the exhibits, 2,532 (53.6%) were at during the second and third trismestre. Crossing data, researchers at Montreal observed that the use of this medication in the last six months of pregnancy was associated with a 1.87 times higher risk of having children with autism spectrum disorder. By contrast, no relationship was found with these drugs in the first three months of pregnancy or during the previous year. The study included information on the use of contraceptives, the child’s diagnosis of autism and many details that allow unravel the specific impact of these drugs. For example, the scientists had in mind when analyzing the data family history (some people are genetically predisposed) or the age of the mother. The results also indicate increased risk of TEA with selective reuptake inhibitors of serotonin, such as Prozac, and using more than one class of antidepressants.
Selective reuptake inhibitors of serotonin have more effect probably because these drugs can cross the placental barrier. They can cause a state which is described as increased serotonin, a neurotransmitter that can modulate neuronal development. Somehow, the association between SSRI and TEA makes biological sense as the process of increasing serotonin is linked to certain abnormalities in the neural development.
However, there are some limitations in their research. For example, the data show prescriptions, not the actual use of antidepressants and lack of information about the lifestyle of the mother.
This study does not mean you can not take antidepressants during pregnancy. In addition, 1.87 times the risk are not very shocking figures. What would have happened if mothers had not taken antidepressants? Untreated depression can also increase prenatal stress, which can lead to increased production of corticosteroids and release of vasoactive amines. This not only predisposes to hypoxia (oxygen deficiency in the blood) or prematurity, may also cause psychiatric disorders such as anxiety, depression and hyperactivity. Depression itself may be a risk factor for autism and may predispose to other psychiatric problems. For this reason, this large sample does not have enough quality to draw conclusions. It is not easy to establish direct and conclusive associations on external factors that can modulate the incidence of autism. More research to specifically assess the risk of autism spectrum disorder related to the types and dosages of antidepressants during pregnancy is needed.
In short, clinical practice must be followed carefully reviewing, evaluating case by case the relationship between the benefits and risks of prescribing antidepressants during pregnancy.