Medical and Ethical Considerations Related to Viable Fetuses with Trisomy 13 in the 36th Week of Pregnancy--a Review of the Literature.

Patau syndrome was first described in 1960 as a group of birth defects caused by trisomy of chromosome 13 (T13). Providing accurate information and relevant reproductive genetic counseling that would allow parents to make informed decisions is not easily accomplished because of the limited information available prenatally. Only 1/3 of all cases of T13 are diagnosed prenatally, which means it cannot be expected that most cases will be detected early in pregnancy, that the parents will decide to terminate the pregnancy, and that difficulties will be avoided.