| Abstrakt: |
OBJECTIVE: To describe the different types of double trisomies diagnosed in spontaneous abortions.STUDY DESIGN: Retrospective review of spontaneous abortions with double trisomies, 1989-99. Maternal reproductive history was obtained by physician contact and medical record review. Data collection is ongoing.RESULTS: There were 42 cases of double trisomy; 20 (47.6%) female and 22 (52.4%) male. The mean maternal age was 39.6 years (22-46); the mean paternal age (n=21) was 40.9 years (33-53). The gestational age ranged 5.8 - 10.2 weeks. A fetal pole was seen in 15/25 (60%). The 16 double trisomies cited for the first time in this study were X/6, 3/21, 4/20, 6/8, 7/8, 7/21, 8/19, 8/21, 10/15, 12/21, 13/14, 14/15, 15/18, 15/marker, 16/18, 20/21. Two cases, X/6 and 8/21 were mosaic; one of the 2 cell lines had a single trisomy. The most common double trisomy was 15/21 (4 cases), followed by 15/20 (3 cases). The chromosomes that were trisomic in more than one double trisomy case were: numbers 21 (18 cases), 15 (14 cases), 20 (8 cases), 18 (7 cases), 16 (6 cases), 14 (5 cases), 8, 13, 22 (4 cases each); 6, 7 (three cases each), 17 (2 cases), and 3, 4, 10, 12, 19 (1 case each). Chromosomes 1, 2, 5, 9, and 11 were not found. Assisted reproductive technology was used in 12/33 cases (36%). Gynecologic pathology was seen in 15/28 (53%) of cases. Reproductive history prior to the index pregnancy (n=34), showed 8 livebom in 7 patients, and 41 spontaneous abortions in 20 patients.CONCLUSION: Advanced maternal age is associated with double trisomy. Chromosomes 21 and 15 are the most frequently involved chromosomes in double trisomy. The mean maternal age of 39.6 years in double trisomy appears higher than that reported for single trisomy, 31 years. This is the largest reported series of double trisomies in spontaneous abortion specimens. This information can aid in the genetic counseling of patients with spontaneous abortions and advanced maternal age. |
