SSRI use in pregnancy and birth defects

A recent case-control analysis from the National Center on Birth Defects compared women who had children with birth defects to those without, to assess the association of the birth defects with specific SSRIs (selective serotonin reuptake inhibitors) taken from the month before  pregnancy and through the third month of pregnancy ​(see depression ssri birth defects bmj2015 in dropbox, or  BMJ 2015;350:h3190​). details:

--17952 mothers of infants with birth defects from US centers in 10 states were compared with 9857 who did not have infants with birth defects. they looked specifically at the birth defects previously reported to be associated with SSRIs, with data from the US National Birth Defects Prevention Study database. Excluded were mothers at higher risk for having children with birth defects for other reasons (diabetes, teratogenic drugs), or those not on SSRIs for psych conditions including depression, bipolar disorder, obsessive compulsive disorder.

--researchers looked at 5 SSRIs (citalopram, escitalopram, fluoxetine, paroxetine, and sertraline), controlling for maternal race/ethnicity, education, smoking and prepregnancy obesity.

--results:

    --3.0% of mothers were on an SSRI (298 women)

    --sertraline was the most commonly used SSRI (38.6% of controls), but there was no association with birth defects (assessed for the previously reported problems of anencephaly, septal defects, anal atresia, limb reduction, omphalocele)

    ​--paroxetine (14.1% of controls) was associated with anencephaly [OR 3.2 (1.6-6.2)]; atrial septal defects [OR 1.8(1.1-3.0)]; right ventricular outflow tract obstruction defects [OR 2.4 (1.4-3.9)]; gastroschisis [OR 2.5 (1.2-4.8)]; and omphalocele [OR 3.5 (1.3-8.0)] (also assessed for previously reported hypospadias, cleft palate)

    --fluoxetine (24.8% of controls) was associated with right ventricular outflow tract obstruction defects [OR 2.0 (1.4-3.1)] and craniosynostosis [OR 1.9 (1.1-3.0)] (also assessed for ventricular septal defects, esophageal atresia)

    --citalopram (9.7% of controls) and escitalopram (8.7% of controls), no association with birth defects, except for marginal association between citalopram and neural tube defects [OR 1.8 (1.0-3.0)]. (citalopram also assessed for ventricular septal defects, cleft lip/palate, hypospadias; escitalopram assessed for septal defects)

so, this was a pretty large database, with presumably pretty thorough data collection, having a few conclusions (though should be confirmed in other large databases)

    --sertraline, which has evolved into being the most prescribed SSRI used in early pregnancy, seems to be pretty safe, not confirming any of the five previously reported birth defects

    --paroxetine should be avoided if possible. that being said, it is important to bear in mind that depression itself may have a significant morbidity an mortality (maternal and fetal), treating depression is very important and often needs meds, and one SSRI may work a lot better than others. so, the perspective here is that the likely very real  higher risk of fetal abnormalities that they found translates to pretty small absolute risks of anencephaly of 2-7/10,000; right ventricular outflow tract obstruction from 10-24/10,000 (assuming the associations are causal).

    ​--the variability of the birth defect risks suggest that it risk is not intrinsic to the serotonin reuptake inhibition itself but to other structure or pharmacokinetic properties of the meds

    ​--in terms of fetal effects of untreated maternal depression, there was a review and set of recommendations from the  American Psychiatric Association and the American College of Obstetricians and Gynecologists (see depression pregnancy management obgyn2009 in dropbox, or doi:10.1016/j.genhosppsych.2009.04.003​), with a few more recent studies. Overall,

            ​--miscarriage rate: some suggestion in the literature of an association, but studies were small and methodologically limited. So, no clear-cut association.

            --growth effects: some studies found increased risk of low-birth-weight and small-for-gestational-age infants, but again poor quality data. 2 more recent studies have found some evidence of decreased fetal weight gain and fetal growth restriction.  So, no clear-cut association.

            --preterm delivery: again, overall not great studies. more recent ones have found modest effect in decreased breast-feeding and more preterm delivery.  So, no clear-cut association.

            --neonatal effects: no clear association with congenital abnormalities. but more neonatal irritability, less activity and attentiveness, and fewer facial expressions; and, small studies have found increased blood cortisol levels and decreased dopamine and serotonin levels (as found in the depressed mothers), and greater neonatal right frontal EEG activation and lower vagal tone.

            --longer-term effects: no data on mothers with Major Depressive Disorder (formally assessed), but instead in mothers with prenatal depressive symptoms, finding that kids at 18 months had greater developmental delay. other studies were less impressive.

    --bottom line to me: good studies have not been done (that I know of) which assess pregnant women with Major Depressive Disorder (which is the group in the general population most responsive to SSRIs) and look at important maternal and fetal/childhood outcomes, including not just the "hard outcomes" of congenital abnormalities, in utero growth, preterm delivery, but also the short-term effects on the pregnant woman (coping skills, function, general sense of well-being) and the longer-term effects on the child (bonding, general assessment of function, happiness, developmental milestones, psychological effects, etc). In the meantime, I think it is important to treat depression in pregnancy, which may well include using medications (as well as support, counseling), and that the BMJ study provides reassurance that there are several antidepressants which are not associated with evident fetal congenital abnormalities, despite some reports to the contrary.