When stress happens matters: effects of earthquake timing on stress responsivity in pregnancy.
OBJECTIVE
The purpose of the study was to assess the effects of the timing of stress during pregnancy on emotional responses and birth outcome. We hypothesized that as pregnancy advanced women would become increasingly resistant to the adverse effects of stress, and so early stress would have more profound effects than later stress.


METHODS
Forty pregnant women who had experienced an earthquake during pregnancy or shortly afterward were identified. Using regression analyses we determined whether the timing of the earthquake was related to an affective response to this event and to length of gestation.


RESULTS
The earthquake was rated as more stressful when it occurred early in pregnancy compared with late in pregnancy, and postpartum ratings were similar to first-trimester ratings (r (quad) =.39; P <.05). Stress experienced early in pregnancy was associated with shorter gestational length (r =.35; P <.05).


CONCLUSIONS
As pregnancy advances, women become decreasingly sensitive to the effects of stress. This decrease in vulnerability may reflect increasing protection of the mother and fetus from adverse influences during pregnancy.
Department of Psychiatry and Human Behavior, University of California, Irvine 92626, USA. lglynn@uci.edu
L M
LM
Glynn
P D
PD
Wadhwa
C
C
Dunkel-Schetter
A
A
Chicz-Demet
C A
CA
Sandman
D003346:Corticotropin-Releasing Hormone / Q000097:blood; D004190:Disasters; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications; D012044:Regression Analysis; D012307:Risk Factors; D013315:Stress, Psychological / Q000150:complications*; D013997:Time Factors
D003346:Corticotropin-Releasing Hormone