MIAMI - Pregnant women with a genetic predisposition to schizophrenia should consider a cesarian delivery to reduce the risk of their baby developing the psychiatric disorder later in life, according to an expert in the field.
A growing body of evidence implicates obstetrical complications, including long labors and oxygen deprivation during birth, as risk factors for schizophrenia, said Dr. Richard Warner, medical director of the Mental Health Centre of Boulder County in Colorado.
Recent studies show a history of obstetrical complications occurs in one-third to more than half of schizophrenic patients, Dr. Warner said during an American Psychiatric Association meeting here.
"If you knew you had a family history, you should think about a C-section," Dr. Warner said. "You should think about very good antenatal care" to avoid any brain injury.
Improved obstetrical care has contributed to the 16% to 30% drop in the rate of schizophrenia over the past 30 years in North America, said Dr. Warner, who is also associate professor-adjunct, in the departments of psychiatry and anthropology at the University of Colorado.
Dr. Warner speculated patients with a genetic predisposition to schizophrenia may have a "nervous system fragility" which renders their brain tissue more sensitive to the effects of oxygen deprivation or intracranial bleeding.
Researchers are uncovering phenomena that further explain the relationship between obstetrical complications and schizophrenia. A series of British studies on poor Afro-Caribbean immigrants found that while the rate of schizophrenia among the first generation was equivalent to the general population, the rate of first hospital admissions among second generation immigrants was up to nine times greater.
"This is an extraordinary new piece of knowledge," said Dr. Warner, author of Recovery from Schizophrenia: Psychiatry and Political Economy.
"My theory is that there's an increased risk of prolonged labor in women who migrate from a poor culture into a more affluent culture.
"Their diet improves and their fetuses are big compared to their own small stature. So you get prolonged labor as a result, which increases the risk of schizophrenia."
These babies tend to survive because of improved technologies. "So you have high survival of oxygen starved babies," he said.
Dr. Warner, who has tracked the epidemiology of schizophrenia around the world, noted that while the disorder is more common among lower classes in urban areas of more affluent cultures, the reverse is true in developing nations like India.
He said this does not contradict the argument that obstetrical complications are crucial to the etiology of schizophrenia.
"The reason the rate is higher in upper castes in India could be the better survival rates in these castes and higher death rates in the lower classes."
As well, he added, food taboos restrict protein intake among pregnant women in the developing world, which results in limiting the size of the fetus and preventing a rise in the number of resulting birth complications.
Recent theories about why schizophrenia appears to come on suddenly - at an average age of 20 in men and 25 in women - focus on brain programming.
"This illness could be programmed to cut in after puberty with the maturation of the brain," Dr. Warner said.
The disease is more severe in men perhaps because of the protective effect of estrogen. After peaking in the mid-20s, the incidence of the disease falls off in women but then picks up again at the time of menopause, Dr. Warner said.
However, there's increasing awareness of possible early signs of the disorder.
Researchers who viewed home movies of children who subsequently developed schizophrenia and their normal siblings could distinguish between the two based on a failure to display a full range of emotions such as joy and excitement, Dr. Warner said.
Copyright © 1995 Maclean Hunter Publishing Limited
Reprinted with permission.
Internet Mental Health (www.mentalhealth.com) copyright © 1995-2011 by Phillip W. Long, M.D.