"Nearly 8 percent of women take antidepressants while pregnant in the U.S.," Time magazine reported last week, following the publication of a new study that assessed the risks to mother and child of drug-related treatment and nontreatment. "Women who took antidepressants during pregnancy were more likely to have babies with reduced head size and had twice the risk of preterm birth, compared with depressed women who did not take medication," health writer Maia Szalavitz reported for the magazine. "Women with untreated depression, in contrast, were more likely to have babies with both smaller body size and reduced fetal head growth."
The study, published last week in the Archives of General Psychiatry and based on cross-checked, self-reported results by close to 8,000 pregnant women in the Netherlands, found that "the reduction in fetal head growth was greater in the SSRI group compared with that seen in the untreated group. The magnitude of the effect of antidepressant use on head size was between that seen in previous studies of tobacco and marijuana use in pregnancy. Smoking reduces fetal head growth by 0.13 millimeters per week, while SSRIs slowed it by 0.18 mm." To put that differently, the secondary effects of SSRIs on fetal head growth were found to be considerably worse than among those who smoke while pregnant.
As if that weren't sufficiently worrying, Szalavitz notes, "the study also found that preterm birth was more common in women taking antidepressants: ... 10.1 percent of those taking SSRIs had a preterm birth," compared with "5.1 percent of women without depression and 6.3 percent of those with untreated depression who delivered prematurely."
Many readers will find it difficult to view such results as a plus, but the authors of the study, urging further studies and careful assessment of their findings, also stress the consequences of untreated depression, including for the head and body size of newborns. In this way, they render the adverse effects of SSRIs the lesser of two evils: "Untreated maternal depression was associated with slower rates of fetal body and head growth. Pregnant mothers treated with SSRIs had fewer depressive symptoms and their fetuses had no delay in body growth but had delayed head growth and were at increased risk for preterm birth. Further research on the implications of these findings is needed."
Clearly, prenatal depression has physiological consequences on newborns. Still, concerning the greater reduction in head growth from SSRIs, the authors note: "Small head size in [newborns] predicts behavioral problems and psychiatric disorders, such as internalizing problems, anxiety and attention-deficit/hyperactivity disorder, and poorer cognitive performance later in life. Importantly, a recent study demonstrated that prenatal exposure to SSRIs might increase the risk of autism spectrum disorders."
Other recent studies, including in Pharmacopsychiatry and the Canadian Journal of Clinical Pharmacology, underscore such concern, having determined that the negative impact—or "transfer"—of SSRI and SNRI antidepressants across the placenta was "substantial," with well-documented adverse effects: "Neonates [or newborns] exposed at term to selective serotonin (SSRI) or serotonin-norepinephrine reuptake inhibitors (SNRI) medications," note the authors of the Canadian study, "may encounter symptoms such as irritability, rigidity, tremor and respiratory distress.... Preliminary evidence suggests that the very early respiratory symptoms may not be part of discontinuation but rather part of a reversible form of persistent pulmonary hypertension of the newborn."
Put another way, untreated depression in pregnant mothers correlates with diminished head and body growth in newborns, but antidepressant treatment for the same population correlates with a larger reduction in head growth, a sizeable risk of premature birth, and "substantial" knock-on effects in the newborn, including cognitive impairment, respiratory distress, and hypertension.
I'm glad the authors of the Dutch study have brought greater attention to prenatal depression. However, their findings about the effects of antidepressants on newborns don't suggest that such drugs are a viable remedy or acceptable risk to either mother or child.