Taking the most popular type of antidepressants during pregnancy does not increase the risk of stillbirth or newborn death, according to the latest sweeping study in a string of investigations probing the safety of pregnant women taking the drugs.
Researchers analyzed data from more than 1.6 million women in Nordic countries, including nearly 30,000 women who had filled a prescription for a selective serotonin reuptake inhibitor (SSRI) while pregnant.
Women who took an SSRI did have higher rates of stillbirth and infant death than those who did not. "However," study co-author Dr. Olof Stephansson, a clinical epidemiologist with Karolinska University Hospital in Sweden told HuffPost, "this was because of an increased proportion of smokers, older [maternal] age, diabetes and hypertensive disease."
"The risk increase," he explained, "was attributed to [those] factors and not the medication."
The data used in the study was obtained from prescription registries in Denmark, Finland, Iceland, Norway and Sweden, as well as from patient and birth registries in those countries. The findings were published in the Journal of the American Medical Association this week and funded, in part, by the Swedish Pharmacy Company.
"This data is some of the best in the world [for] doing population-based research," said Dr. Katherine Moore, an assistant professor of psychiatry with the Mayo Clinic, who did not work on the study. "It integrates data from multiple sources: out-patient and in-patient, pharmacy records. This study offers additional evidence supporting the safety of SSRI use in pregnancy."
A 2009 joint report from the American College of Obstetricians and Gynecologists and American Psychiatric Association found that up to 23 percent of women have at least one depressive episode while pregnant. Women with mild symptoms should consider not using SSRIs during pregnancy, that report recommended, but women with severe depression should continue taking medication as untreated severe depression carries potential risks for both mom and baby.
But not all recent research supports the safety of SSRIs during pregnancy. A widely covered study published in November in the journal Human Reproduction found that pregnant women who take SSRIs may have a greater risk of pregnancy complications, including birth defects, preterm birth and miscarriage.
Dr. Adam Urato, chairman of obstetrics and gynecology at MetroWest Medical Center in Massachusetts and an author on that study, expressed some concerns about the latest research.
"The [JAMA] study looked at information on dispensed drugs, not ingested drugs and these numbers are often quite different," he said in an email to The Huffington Post. "When exposure information is inexact … the result is often that we do not find evidence of harm from a drug," Urato added.
A woman might get misclassified as taking an SSRI and having a good outcome, but actually belonged in the 'not taking an SSRI' group, he said.
Though the authors of the new study found no significant link between SSRI use during pregnancy and risk of stillbirth or newborn death, they stressed that decisions about treatment options must take into account other possible outcomes.
"Previous studies have found an increased risk for congenital cardiac malformations for Paroxetine [known by trade names like Paxil] and a modest risk increase for persistent pulmonary hypertension among newborns," Stephansson said.
"This is the most individualized medicine we can do," agreed Moore. "These risk-benefit discussions are so crucial for each patient and their partner -- if a partner's involved."
"For mild symptoms, we should absolutely consider non-pharmacologic treatments first, to avoid any risk to the fetus," she said. "But when medication is suggested by moderate to severe symptoms of depression, providers and patients can feel confident about the safety of [SSRIs]."
When patients have moderate to severe symptoms, however, "providers and patients can feel confident about the safety of [SSRIs]," said Moore.