Table 2.
Results of the cytogenetic analysis of miscarriages classified by clinical factors n (%)
| Total (n = 364) | Maternal age (years) | Previous miscarriages (n) | Embryonic/fetal size at miscarriagea (mm) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| < 35 (n = 87) | 35 to < 40 (n = 160) | ≥ 40 (n = 117) | p f | < 2 (n = 189) | ≥ 2 (n = 175) | p g | Empty (n = 73) | < 10 (n = 122) | 10 to < 20 (n = 102) | ≥ 20 (n = 67) | p f | ||
| Normal karyotypeb | 64 (17.6) | 28 (32.2) | 25 (15.6) | 11 (9.4) | < 0.001 | 25 (13.2) | 39 (22.3) | 0.023 | 14 (19.2) | 18 (14.8) | 12 (11.8) | 20 (29.9) | 0.203 |
| Abnormal karyotype | 300 (82.4) | 59 (67.8) | 135 (84.4) | 106 (90.6) | < 0.001 | 164 (86.8) | 136 (77.7) | 0.023 | 59 (80.8) | 104 (85.2) | 90 (88.2) | 47 (70.1) | 0.203 |
| Autosomal non-viable trisomyc | 178 (48.9) | 29 (33.3) | 81 (50.6) | 68 (58.1) | 0.001 | 91 (48.1) | 87 (49.7) | 0.765 | 40 (54.8) | 89 (73.0) | 48 (47.1) | 1 (1.5) | < 0.001 |
| Autosomal viable trisomyc | 61 (16.8) | 7 (8.0) | 30 (18.8) | 24 (20.5) | 0.025 | 42 (22.2) | 19 (10.9) | 0.004 | 2 (2.7) | 4 (3.3) | 20 (19.6) | 35 (52.2) | < 0.001 |
| Triploidyd | 16 (4.4) | 9 (10.3) | 4 (2.5) | 3 (2.6) | 0.016 | 9 (4.8) | 7 (4.0) | 0.723 | 4 (5.5) | 3 (2.5) | 6 (5.9) | 3 (4.5) | 0.832 |
| Tetraploidyd | 8 (2.2) | 3 (3.4) | 4 (2.5) | 1 (0.9) | 0.211 | 4 (2.1) | 4 (2.3) | 1.000 | 6 (8.2) | 2 (1.6) | 0 (0.0) | 0 (0.0) | 0.006 |
| Monosomy X | 13 (3.6) | 2 (2.3) | 7 (4.4) | 4 (3.4) | 0.725 | 10 (5.3) | 3 (1.7) | 0.090 | 0 (0.0) | 0 (0.0) | 8 (7.8) | 5 (7.5) | 0.002 |
| Structural abnormalities | 9 (2.5) | 6 (6.9) | 2 (1.3) | 1 (0.9) | 0.017 | 3 (1.6) | 6 (3.4) | 0.322 | 3 (4.1) | 0 (0.0) | 5 (4.9) | 1 (1.5) | 0.992 |
| Monosomy 21 | 2 (0.5) | 0 (0.0) | 1 (0.6) | 1 (0.6) | 0.444 | 1 (0.5) | 1 (0.6) | 1.000 | 0 (0.0) | 1 (0.8) | 1 (1.0) | 0 (0.0) | 0.941 |
| 47,XXY | 1 (0.3) | 0 (0.0) | 1 (0.6) | 0 (0.0) | 0.912 | 1 (0.5) | 0 (0.0) | 1.000 | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (1.5) | – |
| Complicated abnormalitiese | 12 (3.3) | 3 (3.4) | 5 (3.1) | 4 (3.4) | 0.997 | 3 (1.6) | 9 (5.1) | 0.078 | 4 (5.5) | 5 (4.1) | 2 (2.0) | 1 (1.5) | 0.125 |
aEmbryonic/fetal size was determined by vaginal ultrasonography at miscarriage. “Empty” means only a gestational sac was present (anembryonic)
bPericentric inversion 9 was classified as normal karyotype
cMosaicism consisting of a normal and trisomic karyotype was classified as trisomy. Autosomal viable trisomy included trisomies 13, 18, and 21, and autosomal non-viable trisomy included other autosomal trisomy
dPolyploidy with aneuploidy/structural abnormality was classified as polyploidy
eComplicated abnormalities mean that miscarriage specimens had two distinct abnormalities, such as trisomy and monosomy, or aneuploidy and structural abnormality, including mosaicism
fp values were calculated using a trend analysis for maternal age and embryonic/fetal size at miscarriage
gp values were calculated using the chi-squared test or Fisher’s exact test for the number of previous miscarriages