A pregnancy test reveals chromosome 13 trisomy, which is a manifestation of a severe chromosomal abnormality in the fetus, and if this occurs, the fetus may have some malformations in several organ systems. Commonly, trisomy 13 can be manifested in the central nervous system as malformations of the whole forebrain of the fetus, and in addition, the fetus may have cleft lip and palate or severe malformations of the fetal cardiovascular system, and so on. So clinically, trisomy 13 is a series of clinical symptoms of cumulative fetal multi-organ and multi-system malformations, and the prognosis of such fetuses after birth is relatively poor, and the survival period is relatively short. Therefore, if the diagnosis of trisomy 13 can be confirmed through chromosomal examination, it is recommended to terminate the pregnancy.