Pregnant women who take antidepressants such as Prozac and Paxil may be increasing the chances that their babies suffer from irritability, tremors and seizures at birth.

But while the babies of women who took antidepressants in the third trimester of pregnancy were three times more likely to have these symptoms than other babies, the effects were not found to last more than a few weeks, doctors at the University of Pittsburgh School of Medicine report in today's issue of the Journal of the American Medical Association.

Their study, which analyzed previous research on the topic, is meant to inform physicians about the risks of medication during pregnancy, but "by no means is it intended to say that women should not take these medications," said lead author Dr. Eydie Moses-Kolko, a Pitt assistant professor of psychiatry.

These results highlight a dilemma faced by an increasing number of women who endure symptoms of depression: Is it better to go off medication and struggle with depression during pregnancy, or risk taking antidepressants to better deal with the demands of nurturing a child?

As many as 20 percent of women experience some symptoms of depression during pregnancy, and one in 10 women develop major depression during that time, according to a guide published by some of the leading researchers on the topic.

Pregnant women with depression can be treated in a few different ways, including psychotherapy. Pharmaceutical solutions include a type of antidepressants called selective serotonin reuptake inhibitors, or SSRIs, which include Prozac, Paxil and Zoloft; and a type called serotonin/norepinephrine reuptake inhbitiors, or SNRIs, such as Effexor. This study looked at women taking both classes of medication; both types appear to affect babies.

Babies may be irritable because they are experiencing withdrawal -- basically going "cold turkey" off a drug that they've been receiving through a mother's placenta, said Moses-Kolko. The symptoms may also be due to the toxicity of the drugs, some of which stay in the system; a baby's enzymes are not developed enough to purge the system of them quickly.

The most severe symptoms found in the literature review included seizures, vomiting and difficultly breathing; in one case, a baby needed to be intubated. Usually, the babies suffered only short-term, mild effects such as difficulty feeding and sleeping, irritability, and prolonged crying.

Little conclusive research is available on how antidepressants affect newborns. A 2003 study found that babies of women who took SSRIs while pregnant had no more birth defects than non-depressed women, while a 2005 study cautioned doctors against prescribing the medications.

In the spring of 2004, the Food and Drug Administration recommended that SSRI labels include a warning about the possible neonatal effects of the drugs.

Some say they overreacted. Others disagree.

"We can't assume that there's no adverse effects," said Sandy Zeskind, a research professor in pediatrics at the University of North Carolina-Chapel Hill. He believes that there are longer-lasting effects than those that can be explained by withdrawal.

Babies who were prenatally exposed to SSRIs had adverse effects on their central and autonomic nervous systems, according his research, which he presented on Monday at the Pediatric Academic Societies' annual meeting.

Still, women need to weigh the problems of going off medication against how much their depression might affect their child, said Zeskind, because a depressed mother could lead to a depressed baby.

Most women who stop taking antidepressants during pregnancy will suffer from symptoms associated with depression, said Dr. Lee Cohen, director at the Center for Women's Mental Health at Massachusetts General Hospital.

"Failure to keep women well during pregnancy has very significant consequences," he said. Research has shown that the children of women who are depressed during pregnancy can have a whole host of problems, such as premature birth and low birthweight.

Cohen, who serves as a consultant to several antidepressant manufacturers, worries that women may decide to stop taking antidepressants based on studies that he calls incomplete, if not incorrect.

"There is a tendency to discount the severity of depression and the rate at which it impacts on patients' lives both emotionally and medically," he said.

Depression in pregnant women is also the most reliable predictor for post-partum depression, said Adrienne Einarson, assistant director of the Motherisk program at the Hospital for Sick Children in Toronto. She and her colleagues are publishing a study on this topic in next week's Canadian counterpart of JAMA.

Only one drug has been approved by the FDA for use during pregnancy for any condition, said Einarson, and it alleviates the symptoms of morning sickness. This means that for whatever else ails her, a woman who takes medicine during pregnancy might be taking some risk.

Some women may choose to wean themselves off antidepressants during pregnancy, substituting psychotherapy or light therapy for their medications.

Others who decide to stay on the medication may decrease the time between feedings and increase the amount of skin-to-skin contact, the study suggests, preparing for symptoms that may or may not occur.

"There are many women who really need these medications to have any quality of life," Moses-Kolko said.