War Stress During Pregnancy Linked to Schizophrenia in Offspring

According to US study, girls born in Jerusalem during the 1967 war were 4.3 times more likely to get schizophrenia than those in control group.

Ze'ev Ben-Yechiel,

Mental health center in Israel
Mental health center in Israel
Photo: Flash90

Children born to women exposed to extreme stress or trauma during pregnancy are at a significantly greater risk of becoming schizophrenic later in life, according to a study published Thursday on mothers pregnant in Jerusalem during the Six Day War. 

The study, conducted by the New York University School of Medicine, concluded that women exposed to the severe psychological stress of war or other traumatic conditions in the second month of their pregnancy are several times more likely to give birth to children that will ultimately develop the devastating mental illness.

The findings of the study, published online in an open-access and peer-reviewed medical journal from the BioMed Central Publishing house (www.biomedcentral.com) supported the conclusions of other recent studies showing a correlation between exposure to severe stress in pregnant women and a higher rate of severe psychiatric disorders such as schizophrenia. Additional factors found in medical studies to be linked to schizophrenia risk are low birth weight and premature birth.

The disease, considered the most frightening and complex of all psychiatric disturbances, affects about 1% of the Israeli population.

The authors of the study said that their findings are not conclusive and said that their research should not be cause for alarm among expecting mothers. Psychiatrists Dolores Malaspina and Anita and Joseph Steckler stressed that their research "only supports but does not prove" their hypothesis that the second month of fetal development is the one in which the child is most vulnerable to schizophrenia-inducing stress, citing the narrow sample base: 88,829 Jerusalemites born in the capital between 1964 and 1976, collected from the Jerusalem Perinatal Study, linked to birth records from the Israel’s Psychiatric Registry.  They said that the study also did not take into account the length of pregnancy, as premature babies have been found to have a higher risk of developing the disease.

Natural disasters, terrorist attacks or the sudden death of a loved one could have the same effect on the child’s risk of contracting the mental illness as a war zone, say the three doctors, but they also said that pregnant women should “not be alarmed about handling daily stressors during pregnancy. A developing fetus requires some exposure to maternal stress, as it normalizes their stress functioning. But women experiencing anxiety or excessive stress would do well to address it before a planned pregnancy and to have good social support systems."

The battle for Jerusalem, which was won in the third day of the war, endangered the lives of many residents of the capital. The children of Jerusalemite women in their second month of pregnancy at the time were found to have developed a higher incidence of schizophrenia over the following 21 to 33 years. The NYU study found that girls born from that sample were 4.3 times more likely to develop schizophrenia as young adults than those born at other times between 1964 and 1976. Meanwhile, boys were only 1.2 times more likely to do so.

The reasons for the vast gender discrepancy are not clear. Traditionally it was believed that men are at a slightly higher risk for schizophrenia than women, but a study by a group in Germany found that data supporting this conclusion could be skewed by data they found: men tend to develop the disorder three to four years earlier than women.

Commenting on the findings of their study, Dr. Malaspina said, "It's a very striking confirmation of something that has been suspected for quite some time. The placenta is very sensitive to stress hormones in the mother. These hormones were probably amplified during the time of the war."

The findings of the study have been well-received in the Israeli medical community. One senior Israeli psychiatrist said that the study was a very interesting one that “confirms previous reports of an excess incidence of schizophrenia in offspring born to mothers who experienced stress in early pregnancy.”  Prof. Avi Weizman, a senior psychiatrist at Petah Tikva’s Geha Mental Health Center, went on to add that the research “suggests a relatively narrow window of vulnerability in the second month.... It deserves to be replicated in a larger sample," he said in an interview with the Jerusalem Post.

The range of birth years for the children in the sample include 1973, which saw the most intensive war Israel fought since its independence, the Yom Kippur War. That war lasted much longer than the one in 1967, saw higher casualty rates, and was arguably the most stressful one nationwide as it put the country in its greatest risk of defeat since 1948. Prof. Arieh Shalev, chief of the psychiatric division at Hadassah-Hebrew University Medical Center, thinks this war, along with other periods of conflict in Israel, should be the focus of additional studies and repeated the researchers’ advice for pregnant women not to be overly concerned.

"Even if the increased risk of schizophrenia is a few times higher, it is still very low; it can still mean a small minority. Women should not be frightened. Severe stress in pregnant women during the Yom Kippur War, the Lebanon wars and the intifada should also be studied to see if there is support for their hypothesis," said Shalev.

Another expert on mental illness expressed qualified approval of the research, pointing out that it is not the stress itself that creates the risk for pregnant women, but rather the subjective factor of their reaction to it. "The study is important. The authors are clearly on to something, but what is really still missing is a subjective perception of the stress by the mothers,” said Dr. Danny Brom,  psychologist and director of the Temmy and Albert Latner Israel Center for the Treatment of Psychotrauma at Herzog Hospital in Jerusalem.

“One of the most important effects of stress/trauma happens when the person experiences severe helplessness and horror. The study, therefore, as the authors suggest, creates a hypothesis but not proof. This is an interesting direction, but the evidence so far is not very convincing evidence.”

Dr. Brom criticized the researchers for what he considered to be premature publishing of the article. “Although they state that mothers should not be worried, I think that their article creates too much anxiety and possibly guilt feelings in parents without a stable basis for it," he said.