|
|
|
|
|
|
|
|
|
|
By Merritt McKinney
NEW YORK, Mar 28 (Reuters Health) - A stressful experience such as living through a major earthquake appears to have more of an impact on pregnant women early in pregnancy, researchers in California report.
Women in the first trimester of pregnancy when a 6.8-magnitude earthquake struck in 1994 felt more stressed out by the quake than those who were further along or had already given birth, according to results of a study of 40 women who were pregnant or new mothers when the quake occurred.
Stress early in pregnancy also appeared to lead to earlier births, Dr. Laura M. Glynn of the University of California at Irvine and her colleagues report in the March issue of the American Journal of Obstetrics and Gynecology. The investigators found that the earlier a woman was in her pregnancy at the time of the earthquake, the earlier her child was born.
On average, women in the first trimester when the ground shook gave birth after about 38 weeks of pregnancy, compared to almost 39 weeks for women in the third trimester. In contrast, women who had already given birth at the time of the quake gave birth after an average of 39.5 weeks of pregnancy. A full-term pregnancy lasts about 40 weeks.
"The effects of stress do not appear to be uniform across pregnancy," Glynn told Reuters Health. "The effects of early stress seem more detrimental, both in terms of maternal psychological or emotional state and in terms of pregnancy outcome."
This diminishing response to stress may be the body's way of protecting the health of both the mother and the child she carries, the authors suggest.
How stress produces a smaller effect on women as they proceed through pregnancy is uncertain, but one possibility is that the increased levels of certain hormones during pregnancy may blunt a woman's response to stress. One such hormone, corticotropin-releasing hormone, may affect the "placental clock," which plays a role in controlling the length of pregnancy, Glynn's team notes.
Of course, most women do not live in earthquake zones, but the impact of ordinary stress also appears to vary during pregnancy, according to Glynn. Last week, at a meeting of the Society of Behavioral Medicine, she and her colleagues presented study findings showing that 18 different life events triggered less profound psychological responses late in pregnancy.
"This suggests that it is not just emotional responses to an earthquake that are altered as a function of pregnancy, but responses to stressors in general," Glynn said.
Assuming that future research confirms these findings, interventions developed to reduce stress during pregnancy should focus on early pregnancy, which appears to be "a particularly vulnerable time," according to the California researcher.
SOURCE: American Journal of Obstetrics and Gynecology 2001;184:637-642.
| Health Topics | Drug Information | Dictionaries | Directories | Other Resources |
|
U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894
Copyright and Privacy Policy, We welcome your comments. Last updated: 29 March 2001 |