There are a number of possible chromosomal conditions in fetal arrest, many of which are undetectable. These include chromosome number abnormalities and structural abnormalities. Numerical abnormalities are most common with trisomies, and structural abnormalities include balanced translocations, inversions, deletions, chimeras, and overlaps. Chromosomal causes of fetal arrest include chromosome number abnormalities and structural abnormalities. The most common chromosomal abnormalities are trisomy 21, trisomy 18, trisomy 13, trisomy 16, and trisomy 22, followed by haplogroup X. Triploidy and tetraploidy are less common. Structural abnormalities are mainly balanced translocations, inversions, deletions, chimeras, and overlaps. Chromosomal abnormalities in the embryo are the most common cause of early pregnancy arrest. If a woman suffers a first termination, she can get pregnant again; if she suffers two or more terminations, the embryo should be tested for chromosomal abnormalities. Consult your physician for details.