Pregnant women with bipolar disorder at higher risk for developing postpartum psychosis

Pregnant women with bipolar disorder and their families and physicians should be aware of a significantly higher risk for developing postpartum psychosis, according to a new Northwestern Medicine review of literature on the rare and under-researched disorder.

Postpartum psychosis almost always stems from bipolar disorder but is often missed because of its rarity and lack of research on the subject, according to the review from Northwestern Medicine, Stanford University and Erasmus Medical Center in the Netherlands.

Compounding the problem, physicians are reluctant to prescribe lithium for breastfeeding women for fear that the drug will negatively impact the baby. However, a small number of lithium-treated mothers and breastfed babies have been studied and the infants had no adverse effects with careful followup, Wisner said. Lithium is the most effective and fast-acting drug to treat postpartum psychosis.

Postpartum psychosis increases the risk for a mother harming or killing her baby or herself.

"More often than not, the risk of the medication is less than the risk of the uncontrolled disorder," said senior author Dr. Katherine Wisner, the Norman and Helen Asher Professor of Psychiatry and Behavioral Sciences and Obstetrics and Gynecology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine psychiatrist.

"This is a really serious disorder, and no one likes to treat women with medication during pregnancy or breastfeeding, but there's certainly very high risk in not treating as well, such as the risk for suicide," Wisner said.

Lithium is recommended as the first line of medication, according to the review, which was published today, Sept. 9, in The American Journal of Psychiatry.

Awareness of the treatable disorder and diagnosing it can prevent tragedy, according to the review. But because only one or two out of every 1,000 mothers are affected and the lack of research on the disorder, the diagnosis can be missed.

"People think that once you're pregnant, you're not entitled to your body, but what happens to the mother happens to the fetus -- a mentally healthy mom is critical for fetal and infant development," Wisner said. "And these women often experience good responses with lithium treatment."

Postpartum depression should not be confused with postpartum psychosis, Wisner stressed. Women with postpartum depression can have symptoms that can include fatigue, anxiety and often obsessional thoughts, such as fearing they'll put their babies in danger ("What if I drown the baby in the bath?"). They often obsessively wash their hands before touching their babies and check every 10 minutes to make sure their babies are breathing. These thoughts are very distressing to women experiencing postpartum depression, but there are no hallucinations, delusions or psychotic symptoms.

Acute onset postpartum psychosis is much more severe, with women often looking "suddenly disorganized and confused like they're in some sort of delirium," Wisner said. Some sufferers have delusions such as a "dark or out-of-body force makes them want to harm their baby," Wisner added.

Another important finding from the review, Wisner said, was that physicians must distinguish between different treatments for the two groups of women who develop postpartum psychosis: Those who have postpartum-only episodes and those who have more chronic mood episodes throughout and after their pregnancy.

"For women who only have postpartum episodes, I always recommend, 'Baby comes out, lithium goes in,' and you provide immediate medication to prevent an episode of psychosis," Wisner said.

Women with more chronic bipolar disorder usually require medication throughout their pregnancy to remain well, and their physician should monitor their dosing frequently to adjust for the body's metabolic changes throughout pregnancy, Wisner said.

Lastly, the review calls attention to the lack of mother-baby joint care offered at psychiatric hospitals in the United States.

"In other countries, there are mother-baby joint admission units in which the mothers are admitted with the babies, and families can come as well, so they're treated as a unit," Wisner said. "In America, they're admitted to a psychiatric hospital, which may not allow newborn visitation, making it impossible to breastfeed or care for their baby during their recovery."

Due to the small number of postpartum psychosis cases available to study, there are very few experts. The American Journal of Psychiatry requested this review to develop an updated and overarching view of the disorder.

"Everyone knows a woman with bipolar disorder -- it's about one to five percent of the population," Wisner said. "These women need to be aware that postpartum psychosis is a possibility and that there are preventive treatments that are highly effective."