Taking antidepressants during pregnancy may increase the risk of a preterm birth, according to a recent study.

Researchers from Brigham and Women's Hospital, Vanderbilt University, MetroWest Medical Center and Tufts Medical Center found that antidepressant medications taken by pregnant women are associated with increased rates of preterm birth, according to a press release.

"Preterm birth is a major clinical problem throughout the world and rates have been increasing over the past two decades. At the same time, rates of antidepressant use during pregnancy have increased approximately four-fold," Krista Huybrechts, the study's lead author, said in a statement.  "Therefore it is essential to determine what effects these medications have on pregnancy."

For the study, researchers conducted a systematic review and meta-analysis of 41 published studies that evaluated women who took antidepressants during pregnancy and had information on gestational age at birth.

The majority of the 41 studies they reviewed showed increased rates of preterm birth in patients taking antidepressants. The association was strongest with use in the third trimester. There was no evidence of a beneficial effect or reduction in preterm birth with antidepressant use.

"We ... found that the available scientific evidence is becoming clearer that antidepressant use in pregnancy is associated with preterm birth," Adam Urato, study's senior author and a Maternal-Fetal Medicine specialist at Tufts Medical Center and MetroWest Medical Center, said in a statement. "The complication of preterm birth did not appear to be due to the maternal depression but rather it appears likely to be a medication effect."

Children born preterm have higher infant mortality rates than full-term babies and surviving infants are at increased risk of health problems ranging from neurodevelopmental disabilities such as cerebral palsy and intellectual delays to other chronic health problems like asthma.

Preterm birth is the leading cause of infant death and it is also a major contributor to both short and long-term illness," Urato said. "While very preterm infants have the highest risk, we now know that even later preterm birth is associated with significant increases in neonatal morbidity and mortality."

Their findings were published in the journal PLOS ONE.