One of the toughest decisions in clinical psychopharmacology is whether or not to prescribe medication to a patient who is pregnant.  Data is available that supports the connection between antidepressants and birth defects. However, the data is limited in amount and scope and the literature is not in complete agreement about the degree of risk associated with antidepressants.  In fact, the field is not even in complete agreement that there is indeed a connection.

Canadian researchers have shed additional and critical light on this important subject.  Just this year, the British Medical Journal (BMJ) published online a study titled “Antidepressant Use during Pregnancy and the Risk of Major Congenital Malformations in a Cohort of Depressed Pregnant Women: An Updated Analysis of the Quebec Pregnancy Cohort.” Here is what they did, what they found and what it means.

What They Did

The Montreal-based researchers pulled data from the Quebec Pregnancy Cohort (QPC).  Their primary variables of interest included pregnant women with a diagnosis of depression or anxiety, those exposed to an antidepressant medication during the 12 months prior to pregnancy and a live birth.  They were mostly interested in ascertaining if any congenital birth defects (including specific organ defects) were associated with any antidepressants during the child’s first year.

The types of antidepressants used in the analysis include selective serotonin reuptake inhibitors (SSRI), serotonin-norepinephrine reuptake inhibitors (SNRI), tricyclic antidepressants (TCA) and “others.”

The sample size was large at 18,847 women.  Pregnant women taking antidepressants were compared to those who were not.

What They Found

The results are alarming and support the notion that birth defects are associated with antidepressant use during the first trimester of pregnancy.  Specific risks associated with specific medications include: paroxetine (heart defects, particularly ventricular and atrial septal defects); citalopram (musculoskeletal defects and craniosynostosis); and venlafaxine (respiratory defects).  The TCAs were associated with greater risk of eye, ear, face, neck and digestive problems.  It should be noted, however, that the risk associations between the medications and birth defects are very low and occurrence of these defects is still quite rare.

As with most studies, there are several strengths and weaknesses. The authors report two notable strengths as being the large sample size and a sample with diverse and broad data available (e.g., potential confounds).  Notable limitations include potential for recall bias (patients misremembering important information) and the large number of comparisons that were made of medications between the two groups. The authors state that this could lead to results that are a byproduct of chance.

What Does it Mean?

The decision to prescribe medication to a pregnant woman, regardless of psychiatric illness, is a difficult one.  We have further support that antidepressant medications can and do hurt the developing fetus.  But, we also know that untreated depression can lead to problems during gestation to include spontaneous abortion.

We also know that severely depressed pregnant women are less likely to adhere to healthy prenatal nutritional plans.  They are more likely to smoke or drink.  Sleep is less regulated.  And in extreme cases, suicide occurs.

When faced with the dilemma of prescribing or not prescribing medication to a depressed pregnant woman it is imperative that adequate informed consent is obtained.  The patient should be fully aware of the risks associated with taking antidepressant medication during pregnancy. The decision should be a joint one between the patient and prescriber.  And at any time the patient’s concerns about taking medication during this vulnerable time should be acknowledged, considered and validated.

Points to Remember

■ Research shows that antidepressants increase birth defects in pregnant women

■ Serotonergic medications seem to carry the greatest risk

■ Patients should fully understand the risks associated with taking antidepressant medication during pregnancy during the first trimester

■ The decision to prescribe medication to a pregnant woman should be jointly made between the patient and prescriber

■ Not treating depression pharmacologically can also cause indirect harm to the developing fetus

Reference

Bérard, A., Zhao, J., & Sheehy, O.  (2017). Antidepressant Use during Pregnancy and the Risk of  Major Congenital Malformations in a Cohort of Depressed Pregnant Women: An                         Updated Analysis of the Quebec Pregnancy Cohort. BMJ Open, 7. doi: 10.1136/bmjopen-2016-013372.