To study the impact of chronic, life-threatening stressors in the form of daily missile attacks, for five consecutive years, on pregnancy outcomes.

Charts of deliveries from two neighboring towns in the south of Israel, covering the years 2000 and 2003–2008, were reviewed retrospectively. One city had been exposed to missile attacks, while the other was not. For each year, 100 charts were chosen at random.

Significant association was found between exposure to stress and frequency of pregnancy complications (P = 0.047) and premature membrane rupture (P = 0.029). A more detailed analysis, based on dividing the stressful years into three distinct periods: early (2003–2004), intermediate (2005–2006) and late (2007–2008), revealed that preterm deliveries were significantly more frequent (P = 0.044) during the intermediate period, as was premature membrane rupture during the late period (P = 0.014).

Exposure to chronic life-threatening stress resulted in more pregnancy complications and in particular more premature membrane ruptures. The impact was most significant during the middle period of the 5-year-exposure to the stressor. Hence it seems that factors of duration and habituation may play a role in the impact of chronic, life-threatening stressors on pregnancy.