The incidence of significant birth defects or genetic disorders in pregnancy is approximately 3%. Some will be found to have a congenital or genetic defect during childhood or early adulthood. The demands of modern society are for a healthy 'perfect' baby. Recent technological advances have enabled the development of techniques aimed at early diagnosis of the abnormal fetus, at a point where parents who wish to do so may terminate the pregnancy. Some of these techniques render the woman and fetus at risk of harm, whereas in others, efficacy has not yet been established. The implementation of these techniques raises several ethical questions which will be discussed in this article. We will also give a concise scientific background to the available techniques.