Despite concerns that antidepressant use during pregnancy might affect infants’ growth and development, a small new study finds no size differences in the first year of life between babies exposed and not exposed to the drugs.

The medications — known as selective serotonin reuptake inhibitors, or SSRIs, which include fluoxetine (marketed as Prozac) and citalopram (Celexa) — have been tied to premature births and lower birth weight. But their effect on growth during infancy had not been studied.

“It’s a reassuring finding in that when you have an illness during pregnancy, you want to know what is the impact of the illness and what is the impact of the medication,” Katherine Wisner, the study’s lead author, said.

Untreated depression also didn’t seem to influence infant growth, according to Wisner, the director of Northwestern University’s Asher Center for the Study and Treatment of Depressive Disorders.

That’s important because a baby’s most rapid growth happens in the first year, which sets the stage for growth patterns for the whole lifes pan, she added.

Wisner and her colleagues tracked 97 pregnant women without depression, 46 on antidepressants and 31 with depression that was not treated with medication. Their babies were measured and weighed four times over the first year of life.

Almost 20 percent of the women on SSRIs gave birth prematurely — before 37 weeks of gestation — compared with 10 percent of the depressed, non-medicated women and 5 percent of women without depression; these rates were consistent with previous studies.

However, neither depression nor SSRIs were associated with lower weight, shorter length or smaller head size at two weeks, three months, six months and one year.

“This is a good study with some significant limitations, which is inherent in this kind of work,” according to Richard Shelton, a psychiatrist who studies antidepressants and pregnancy at the University of Alabama at Birmingham and was not involved in the study.

Previous studies have found that babies exposed to SSRIs tend to have more problems immediately after birth, Shelton said.

Babies can be less responsive and more irritable, which may be caused by withdrawal from the drugs they’ve had in their systems, Shelton said. One of his studies also found that SSRI-
exposed babies had a slightly increased risk of seizures after birth.

Depression alone has been linked to risks as well, including low birth weight, Wisner said. There’s also a large body of evidence on the risks to a child’s psychological development from growing up in a home with a depressed mom.

Wisner has received grant money for Pfizer, which markets antidepressants. The new study — published in the American Journal of Psychiatry — was funded by the National Institute of Mental Health.