Association of stressful life events with chromosomally normal spontaneous abortion.

Spontaneous abortion is the most common adverse reproductive outcome. Despite evidence that negative life events increase risk for a number of medical disorders, their role in pregnancy disruption has not been investigated. The present study tested an a priori hypothesis that recent negative life events increase the odds of spontaneous abortion of a chromosomally normal conceptus. Between 1984 and 1986, 192 women aged 18-42 years who visited a medical center after spontaneous abortion were interviewed about positive and negative events that had occurred in the 4-5 months preceding the loss. Subsequently, women with chromosomally normal (n = 111) and chromosomally abnormal (n = 81) losses were identified on the basis of tissue culture after interview. The women with chromosomally abnormal loss provided an estimate of the expected frequency of life events against which to compare the event frequencies of women with chromosomally normal loss. Analyses were adjusted for duration of the recall period, payment status, maternal age, education, and ethnicity. Seventy percent of the women with chromosomally normal losses reported having had one or more negative life events in the months preceding loss, compared with 52% of the women with chromosomally abnormal losses (adjusted odds ratio = 2.6, 95% confidence interval (CI) 1.3-5.2). For private patients (n = 69), the adjusted odds ratio was 4.2 (95% CI 1.3-13.4); for public patients (n = 123), it was 1.9 (95% CI 0.8-4.8). The associations held for postconception events alone and were absent for positive events. Results were unaltered by adjustment for smoking, caffeine intake, and alcohol consumption. With recall bias precluded by the study design, the strength, timing, and specificity of these associations suggest that recent negative life events play a role in chromosomally normal spontaneous abortion. Efforts to replicate these results and to elucidate underlying biologic mechanisms are required.