Stress and preterm birth
More than 80 scientific investigations on stress and
PTB were recently reviewed by Dunkel Schetter and
Glynn [7&&], of which a majority had prospective
designs, large samples, and validated measures,
and were fairly well controlled for confounds such
as medical risks, smoking, education, income, and
parity. These studies can be grouped by the type
of stress examined. Of the more than a dozen
published studies assessing ‘major life events in
pregnancy’, a majority found significant effects;
women who experienced major life events such as
the death of a family member were at 1.4 to 1.8 times
greater risk of PTB, with strongest effects when
events occurred early in pregnancy. The majority
of a second, smaller group of studies on catastrophic, community-wide disasters (e.g., earthquakes
or terrorist attacks) also showed significant
effects on gestational age at birth or PTB. A third
small set of studies on chronic stressors, such as
household strain or homelessness, all reported significant
effects on PTB. Finally, a majority of past
investigations on neighborhood stressors such as
poverty and crime indicated significant effects on
gestational age or PTB. In comparison, studies on
daily hassles and perceived stress did not consistently
predict PTB. Thus, of the many distinguishable
forms of stress, many (but not all) contribute to the
risk of PTB.