据报道，丹麦哥本哈根大学(University of Copenhagen)对超过9万名当地孕妇进行分析研究指出，25%以上第1次流产的案例，事实上都可以避免。
哥本哈根大学资深研究员安德森(Anne-Marie Nybo Andersen)指出，不论是年轻或年长的妇女，连同那些有政策影响力的人都应该了解，35岁后再怀孕大幅提高流产的风险。
Objective To identify modifiable risk factors for miscarriage and to estimate the preventable proportion of miscarriages that could be attributed to these. Design Nationwide observational follow-up study. Setting Denmark. Population Ninety-one thousand four hundred and twenty seven pregnancies included in the Danish National Birth Cohort between 1996 and 2002. Methods Information on potentially modifiable risk factors before and during pregnancy was collected by means of computer-assisted telephone interviews and linkage with Danish registers, ensuring almost complete follow-up of pregnancy outcome. Modifiable risk factors for miscarriage were identified by multiple Cox regression analysis, which provided the background for our estimations of population attributable fractions. In all, 88 373 pregnancies had full information on all covariates and were included in this analysis. Main outcome measures Miscarriage before 22 completed weeks of gestation. Results The potentially modifiable pre-pregnant risk factors associated with increased miscarriage risk were: age of 30 years or more at conception, underweight, and obesity. During pregnancy the modifiable risk factors were: alcohol consumption, lifting of >20 kg daily, and night work. We estimated that 25.2% of the miscarriages might be prevented by reduction of all these risk factors to low risk levels. Modification of risk factors acting before and during pregnancy could lead to prevention of 14.7 and 12.5%, respectively, of the miscarriages. Maternal age at conception and alcohol consumption were the most important risk factors. Conclusions Miscarriage risk is increased by multiple potentially modifiable risk factors and a considerable proportion of miscarriages may be preventable.