Trisomy 1 in a clinically recognized IVF pregnancy.

Most chromosomal trisomies lead to spontaneous abortion. To date, trisomies of all human chromosomes have been observed. Chromosome 1 has been the most elusive, as trisomy 1 was the last aberration to be identified. To date there has been only one case report of a full trisomy 1 in the literature [1997: Am J Med Genet 68:98]. We have identified a second full trisomy 1 from the chromosome analysis of products of conception. We present a patient who conceived by in vitro fertilization (IVF). The cellular divisions of the fertilized egg were carefully monitored prior to transfer. Hormonal changes (increased hCG) indicated that implantation had occurred. Vaginal ultrasound demonstrated a gestational sac. At 42 days postfertilization no fetal heart beat could be detected. Cytogenetic analysis of the chorionic villi isolated from the products of conception found that all of the cells analyzed contained a 47,XY,+1 chromosomal complement.