Table 4.
Results of subgroup analyses
| MTHFR C677T | |||||
| Subgroup | Genetic model | No. of study | OR(95% CI) | Test for subgroup differences | |
| χ2 | P | ||||
| Ethnicity | Dominant | 0.99 | 0.32 | ||
| Caucasian | 67 | 1.47(1.25, 1.74) | |||
| Non-Caucasian | 18 | 1.28(1.03, 1.59) | |||
| Recessive | 0.33 | 0.57 | |||
| Caucasian | 67 | 1.65(1.37, 1.98) | |||
| Non-Caucasian | 18 | 1.47(1.06, 2.05) | |||
| Number of PL | Dominant | 0.06 | 0.8 | ||
| ≥ 2 | 51 | 1.46(1.24, 1.73) | |||
| ≥ 3 | 28 | 1.52(1.18, 1.96) | |||
| Recessive | 0.82 | 0.37 | |||
| ≥ 2 | 51 | 1.54(1.25, 1.90) | |||
| ≥ 3 | 28 | 1.79(1.39, 2.32) | |||
| Gestational age at PL | Dominant | 0.02 | 0.89 | ||
| Early pregnancy loss | 14 | 1.39(0.99, 1.95) | |||
| Late pregnancy loss | 31 | 1.43(1.16, 1.67) | |||
| Recessive | 0.12 | 0.73 | |||
| Early pregnancy loss | 14 | 1.38(0.98, 1.95) | |||
| Late pregnancy loss | 31 | 1.49(1.17, 1.89) | |||
| MTHFR A1298C | |||||
| Subgroup | Genetic model | No. of study | OR(95%CI) | Test for subgroup differences | |
| χ2 | P | ||||
| Ethnicity | Dominant | 5.09 | 0.02 | ||
| Caucasian | 30 | 1.88(1.32, 2.69) | |||
| Non-Caucasian | 10 | 1.15(0.91, 1.46) | |||
| Recessive | 4.13 | 0.04 | |||
| Caucasian | 30 | 2.14(1.55, 2.94) | |||
| Non-Caucasian | 10 | 1.36(1.01, 1.82) | |||
| Number of PL | Dominant | 1.09 | 0.3 | ||
| ≥ 2 | 26 | 1.51(1.15, 1.98) | |||
| ≥ 3 | 12 | 2.23(1.12, 4.42) | |||
| Recessive | 3.96 | 0.05 | |||
| ≥ 2 | 26 | 1.48(1.15, 1.90) | |||
| ≥ 3 | 12 | 2.72(1.58, 4.69) | |||
| Gestational age at PL | Dominant | 0.81 | 0.37 | ||
| Early pregnancy loss | 7 | 1.35(0.78, 2.33) | |||
| Late pregnancy loss | 15 | 1.96(1.07, 3.60) | |||
| Recessive | 0.08 | 0.78 | |||
| Early pregnancy loss | 7 | 1.97(1.29, 3.01) | |||
| Late pregnancy loss | 15 | 2.10(1.20, 3.69) | |||
| ACE I/D | |||||
| Subgroup | Genetic model | No. of study | OR(95%CI) | Test for subgroup differences | |
| χ2 | P | ||||
| Ethnicity | Dominant | 0.07 | 0.79 | ||
| Caucasian | 22 | 1.25(0.99, 1.57) | |||
| Non-Caucasian | 4 | 1.13(0.56, 2.29) | |||
| Recessive | 0.87 | 0.35 | |||
| Caucasian | 22 | 1.17(0.95, 1.43) | |||
| Non-Caucasian | 4 | 0.63(0.18, 2.24) | |||
| Number of PL | Dominant | 0.15 | 0.7 | ||
| ≥ 2 | 16 | 1.25(0.93, 1.69) | |||
| ≥ 3 | 10 | 1.15(0.86, 1.55) | |||
| Recessive | 1.76 | 0.19 | |||
| ≥ 2 | 16 | 1.23(0.96, 1.58) | |||
| ≥ 3 | 10 | 0.88(0.57, 1.35) | |||
| Gestational age at PL | Dominant | 4.11 | 0.04 | ||
| Early pregnancy loss | 2 | 2.40(1.24, 4.65) | |||
| Late pregnancy loss | 14 | 1.19(1.00, 1.41) | |||
| Recessive | 0.26 | 0.61 | |||
| Early pregnancy loss | 2 | 1.62(0.48, 5.53) | |||
| Late pregnancy loss | 14 | 1.17(0.95, 1.43) | |||
| PAI-1 4G/5G | |||||
| Subgroup | Genetic model | No. of study | OR(95%CI) | Test for subgroup differences | |
| χ2 | P | ||||
| Ethnicity | Dominant | 3.89 | 0.05 | ||
| Caucasian | 30 | 1.76(1.41, 2.19) | |||
| Non-Caucasian | 4 | 1.22(0.91, 1.63) | |||
| Recessive | 0.32 | 0.57 | |||
| Caucasian | 30 | 1.87(1.41, 2.48) | |||
| Non-Caucasian | 4 | 1.50(0.74, 3.05) | |||
| Number of PL | Dominant | 0.01 | 0.94 | ||
| ≥ 2 | 25 | 1.67(1.31, 2.14) | |||
| ≥ 3 | 8 | 1.64(1.06, 2.55) | |||
| Recessive | 0.81 | 0.37 | |||
| ≥ 2 | 25 | 1.60(1.25, 2.04) | |||
| ≥ 3 | 8 | 2.31(1.07, 4.97) | |||
| Gestational age at PL | Dominant | 4.98 | 0.03 | ||
| Early pregnancy loss | 5 | 2.05(1.56, 2.68) | |||
| Late pregnancy loss | 15 | 1.33(1.02, 1.73) | |||
| Recessive | 1.69 | 0.19 | |||
| Early pregnancy loss | 5 | 2.12(0.96, 4.68) | |||
| Late pregnancy loss | 15 | 1.23(0.98, 1.54) | |||
| Factor VIII V34L | |||||
| Subgroup | Genetic model | No. of study | OR(95%CI) | Test for subgroup differences | |
| χ2 | P | ||||
| Number of PL | Dominant | 0.12 | 0.73 | ||
| ≥ 2 | 10 | 1,31(0.92, 1.86) | |||
| ≥ 3 | 4 | 1.19(0.75, 1.88) | |||
| Recessive | 5.14 | 0.02 | |||
| ≥ 2 | 10 | 1.55(0.79, 3.05) | |||
| ≥ 3 | 4 | 0.38(0.14, 1.05) | |||
| Gestational age at PL | Dominant | 0.35 | 0.55 | ||
| Early pregnancy loss | 4 | 1.58(0.77, 3.21) | |||
| Late pregnancy loss | 2 | 1.35(0.73, 2.50) | |||
| Recessive | 0.32 | 0.57 | |||
| Early pregnancy loss | 4 | 1.12(0.17, 7.27) | |||
| Late pregnancy loss | 2 | 2.23(0.50, 10.01) | |||
| Factor V R2 | |||||
| Subgroup | Genetic model | No. of study | OR(95%CI) | Test for subgroup differences | |
| χ2 | P | ||||
| Ethnicity | Dominant | 0.3 | 0.58 | ||
| Caucasian | 12 | 1.09(0.63, 1.88) | |||
| Non-Caucasian | 1 | 1.44(0.62, 3.38_ | |||
| Number of PL | Dominant | 0 | 1 | ||
| ≥ 2 | 11 | 1.13(0.62, 2.05) | |||
| ≥ 3 | 2 | 1.12(0.59, 2.14) | |||
| Gestational age at PL | Dominant | 0.73 | 0.39 | ||
| Early pregnancy loss | 3 | 1.70(0.50, 5.80) | |||
| Late pregnancy loss | 4 | 0.84(0.28, 2.45) | |||
| β-Fibrinogen-455G/A | |||||
| Subgroup | Genetic model | No. of study | OR(95%CI) | Test for subgroup differences | |
| χ2 | P | ||||
| Ethnicity | Dominant | 0.19 | 0.66 | ||
| Caucasian | 11 | 0.93(0.61, 1.43) | |||
| Non-Caucasian | 1 | 0.71(0.22, 2.25) | |||
| Recessive | 1.56 | 0.21 | |||
| Caucasian | 11 | 1.37(0.79, 2.39) | |||
| Non-Caucasian | 1 | 0.19(0.01,4.06) | |||
| Number of PL | Dominant | 0.26 | 0.61 | ||
| ≥ 2 | 10 | 0.94(0.58, 1.53) | |||
| ≥ 3 | 2 | 0.80(0.53, 1.19) | |||
| Recessive | 1.5 | 0.22 | |||
| ≥ 2 | 10 | 1.75(0.77, 3.96) | |||
| ≥ 3 | 2 | 0.87(0.41, 1.85) | |||
| Gestational age at PL | Dominant | 1.3 | 0.25 | ||
| Early pregnancy loss | 2 | 0.49(0.27, 0.90) | |||
| Late pregnancy loss | 3 | 1.15(0.31, 4.30) | |||
| Recessive | 1.84 | 0.18 | |||
| Early pregnancy loss | 2 | 3.03(0.59, 15.49) | |||
| Late pregnancy loss | 3 | 0.82(0.32, 2.10) | |||
| PL, pregnancy loss | |||||