WEDNESDAY, June 4, 2014 (HealthDay News) — Although antipsychotic medications have not been shown to cause birth defects, new research suggests these drugs can have other harmful effects on babies.

Antipsychotic drugs are used to treat a range of mental illnesses, such as schizophrenia, depression and bipolar disorder. An Australian study found that babies born to women on these medications are more likely to spend time in a neonatal intensive care unit (NICU) or to need specialized care after birth.

The researchers cautioned that health guidelines for the use of antipsychotic drugs during pregnancy should be clarified.

“There’s been little research on antipsychotic medication during pregnancy, and if it affects babies. The lack of data has made it very difficult for clinicians to say anything conclusively on how safe it is for babies,” lead investigator, Jayashri Kulkarni, director of the Monash Alfred Psychiatry Research Center, said in a Monash University news release.

“This new research confirms that most babies are born healthy, but many experience neonatal problems, such as respiratory distress,” Kulkarni explained.

The seven-year observational study, published online recently in PLOS ONE, included 147 Australian women on antipsychotic medications. The women were interviewed every six weeks throughout their pregnancy. They were also followed for the first year after their baby was born.

The investigators found that 43 percent of the babies born to the women in the study spent time in a special care nursery or NICU.

Among the reasons the babies required specialized care:

• 18 percent were born prematurely
• 37 percent showed signs of respiratory distress
• 15 percent developed symptoms of withdrawal

The study authors pointed out that women have higher rates of anxiety disorders than men. They added that the development of new antipsychotic drugs have controlled a number of mental disorders, allowing women on these medications to have children.

“The potentially harmful effects of taking an antipsychotic drug in pregnancy have to be balanced against the harm of untreated psychotic illness,” cautioned Kulkarni. “The good news is we now know there are no clear associations with specific congenital abnormalities [birth defects] and these drugs. However, clinicians should be particularly mindful of neonatal problems such as respiratory distress.”

While the study found an association between use of these medications during pregnancy and certain neonatal problems, it did not prove a cause-and-effect relationship.

More information

Visit the U.S. National Institute of Mental Health for more on antipsychotic medications.