Smoking has been linked with an increased risk for euploid abortion (Kline and coworkers, 1980). Two studies suggested that the abortion risk increased in a linear fashion with cigarettes smoked per day (Armstrong and colleagues, 1992; Chatenoud and associates, 1998). Subsequent studies, however, failed to support this association (Maconochie, 2007; Rasch, 2003; Wisborg, 2003, and all their coworkers).
Both spontaneous abortion and fetal anomalies may result from frequent alcohol use during the first 8 weeks of pregnancy (Floyd and coworkers, 1999). The risk seems to be related to both frequency and dose (Armstrong and associates, 1992). A low level of alcohol consumption during pregnancy was not associated with a significant risk for abortion (Kesmodel and associates, 2002; Maconochie and coworkers, 2007).