The labels of all antipsychotic drugs have been revised to include information on their effects on newborns when women take them during the third trimester of pregnancy. Adverse effects can occur when the antipsychotics cross the placenta, and infants born to mothers receiving these drugs may experience abnormal muscle movements (extrapyramidal symptoms) or withdrawal symptoms.

The Food and Drug Administration's Adverse Event Reporting System database shows that through October 28, 2009, there had been 69 cases of extrapyramidal or withdrawal symptoms in neonates that were related to maternal antipsychotic use. The effects reported in those case reports include agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, and feeding disorder. The symptoms have varied in intensity (with recovery occurring without treatment in some cases and requiring intensive care in others), onset (occurring within hours after birth to as long as a month after birth), and duration (ending in some cases within hours of onset; in others only after prolonged hospitalization).

Case reports are difficult to interpret because the information reported isn't equally comprehensive and a variety of confounding variables are involved, such as the concomitant use of other drugs, prematurity, congenital malformations, and obstetrical and perinatal complications. Case reports also don't provide the blood levels of the antipsychotics involved, so it's difficult to determine whether reported events are related to drug toxicity or to withdrawal. Some cases occurred only with antipsychotic use alone and suggest neonatal extrapyramidal symptoms or withdrawal (or both). It should also be remembered that case reports don't carry the same level of evidence a randomized clinical trial does; they shouldn't be taken as absolute proof that antipsychotics cause extrapyramidal symptoms or withdrawal.

Nurses should be aware of these risks and be able to discuss them with patients. Nurses who care for newborns should assess the mothers for antipsychotic use and monitor the newborn accordingly. Women who are concerned about these possible effects on their newborn should have a conversation with their prescriber to determine whether they can be weaned off of the antipsychotic safely.