If you are pregnant or think you might be pregnant, don't take Accutane. Use reliable birth control to avoid pregnancy if you do use it. Miscarriage Miscarriage occurs when a pregnancy ends before the embryo or fetus can survive on its own outside the uterus. We don't usually know and are often unable to find out what causes a miscarriage. The most common finding in early miscarriages is an abnormality in the development of the early embryo.
Studies indicate more than half of all early miscarriages have chromosomal abnormalities.
Called teratogens, these adverse factors are discussed in depth in Week 9. We believe various maternal factors are important in some miscarriages. Unusual infections, such as listeria, toxoplasma and syphilis, have been implicated in miscarriages. We have no concrete evidence that deficiency of any particular nutrient or even a moderate deficiency of all nutrients causes a miscarriage. Women who smoke have a higher rate of miscarriage.