Which SSRI in pregnancy ?
Fluoxetine is considered to be the first choice antidepressant for use in pregnancy. However, there is little
evidence that paroxetine or citalopram pose greater risks and treatment choice should be based on history of previous
response rather than safety concerns.
The risks and benefits of any switch in treatment should be considered. For example, a woman who is responding well
to paroxetine and becomes pregnant may be put at risk if an attempt is made to switch to another SSRI where clinical
response is uncertain.
Both depressive symptoms and exposure to antidepressants during pregnancy are associated with foetal growth changes
and shorter gestation time. The relative effects are difficult to determine as the majority of studies that have evaluated
the risk of antidepressant use have been unable to control for the possible effects of a depressive disorder. Short term
neonatal behavioural changes and irritability are also linked to both maternal depression and antidepressant treatment.21
Several studies have reported foetal malformations in association with first trimester exposure to antidepressants,
but there is no specific pattern of defects associated with individual drugs or drug classes. SSRIs are widely used in
pregnancy and a recent study estimated that 2.3% of pregnant women are exposed to SSRIs.22
There has been recent concern about an increased risk of cardiac malformations with first trimester exposure to paroxetine.
This led to warnings and recommendations against the use of paroxetine for the treatment of depression in pregnancy, especially
during the first trimester. Fluoxetine then emerged as the SSRI of choice for the treatment of depression in pregnancy.
However, a recent review conducted in the UK has concluded that the risks of cardiac malformations associated with paroxetine
and fluoxetine are similar.23 This report further stated that the risk of a foetal cardiac abnormality is increased
from 1% to 2% with antenatal exposure to fluoxetine - an absolute risk increase of about 1%, similar to that reported
with paroxetine. These figures are still debated due to study design problems and the influence of confounding factors.
Although fluoxetine remains the preferred SSRI for use in pregnancy there is no strong evidence that it is any safer than
paroxetine or the other SSRIs.
All SSRIs are associated with a small increased risk of persistent pulmonary hypertension in new-born infants. The background
rate of this condition is 0.5 - 2 per 1000 and it has been estimated that SSRI exposure in pregnancy increases this to
3 - 6 per 1000.21
All antidepressants taken during late pregnancy can give rise to neonatal withdrawal symptoms. Symptoms with SSRIs include
irritability and feeding problems but they are usually mild and short-lived. These symptoms are probably less likely with
fluoxetine due to its longer half-life. Venlafaxine can cause similar withdrawal symptoms.
TCAs, e.g. amitriptyline, imipramine and nortriptyline, have been used for many years in pregnancy and are considered
relatively safe. However, in practice, an SSRI is considered preferable as they are better tolerated and are less toxic