According to the researchers, from the University of Pennsylvania in Philadelphia, USA, the study is one of the first to examine the role of psychosocial stress on early pregnancy loss.

They recruited 326 pregnant women who presented at the university hospital's emergency department, and followed them through to 22 weeks' gestation. The study cases were those women who experienced a spontaneous abortion, and controls were those whose pregnancy continued beyond the 22 week cut-off point.

At recruitment, all of the women completed three psychosocial stress questionnaires: the Perceived Stress Scale, the Prenatal Social Environment Inventory, and the Index of Spousal Abuse. These measured both external stress and subjective, perceived stress, whether chronic or acute. Blood and urine samples were also collected.

Writing in the latest issue of the journal Annals of Epidemiology, the researchers report no relationship between the level of psychosocial stress — as determined by the three stress scales and by cortisol levels  —and the risk of spontaneous abortion.

However, they say that women with high levels of stress as measured by the Prenatal Social Environment Inventory were more likely than women with lower levels of stress to use cigarettes or marijuana during pregnancy.

Role of stress "unclear"

The Philadelphia researchers conclude: "The influence of psychosocial stress on the risk of spontaneous abortion is unclear. The results of this study do not support the hypothesis that psychosocial stress during early pregnancy is related to an increased risk of spontaneous abortion."

They add that the data do suggest that chronically high stress is associated with cigarette and marijuana use during pregnancy, "which presents a considerable health risk both to the mother and to the fetus."

Source: Annals of Epidemiology 2003; 13: 223-9, Issue 10: 19 May 2003