There is no evidence that there are any health benefits related to eating the placenta post birth, a review says.

Eating one's own placenta after giving birth may be trendy but there is no scientific evidence that women derive any benefits from it, researchers said Thursday.

A review of 10 previously published studies showed no "human or animal data to support the common claims that eating the placenta - either raw, cooked or encapsulated - offers protection against postpartum depression, reduces post-delivery pain, boosts energy, helps with lactation, promotes skin elasticity, enhances maternal bonding or replenishes iron in the body," said the study by experts at Northwestern University.

Nor was there any data on the potential risks of the practice, which has been touted by reality show star Kourtney Kardashian, among others.

"There are a lot of subjective reports from women who perceived benefits, but there hasn't been any systematic research investigating the benefits or the risk of placenta ingestion," said co-author Crystal Clark, assistant professor of psychiatry and behavioural sciences at Northwestern University Feinberg School of Medicine.

"The studies on mice aren't translatable into human benefits."

The placenta is an organ that develops in the uterus during pregnancy to provide nutrients to the fetus and remove waste products from the infant's blood. Most mammals, including cats, eat it after birth.

The first documented accounts of women doing it in North America date back to the 1970s, according to the Northwestern study.

"The popularity has spiked in the last few years," Clark said.

"Our sense is that people aren't making this decision based on science or talking with physicians. Some women are making this based on media reports, blogs and websites."
The study was published June 4 in Archives of Women's Mental Health.