Comparison 2.
Early versus second trimester amniocentesis
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
|---|---|---|---|---|
| 1 Not complied with allocated procedure | 1 | 4368 | Risk Ratio (M-H, Fixed, 95% CI) | 0.65 [0.57, 0.75] |
| 2 Sampling failure | 1 | 629 | Risk Ratio (M-H, Fixed, 95% CI) | 4.53 [0.53, 38.56] |
| 3 Multiple insertions | 1 | 4368 | Risk Ratio (M-H, Fixed, 95% CI) | 2.79 [1.92, 4.04] |
| 4 Second test performed | 1 | 4107 | Risk Ratio (M-H, Fixed, 95% CI) | 8.72 [3.47, 21.91] |
| 5 Laboratory failure | 1 | 4368 | Risk Ratio (M-H, Fixed, 95% CI) | 9.76 [3.49, 27.26] |
| 6 All non-mosaic abnormalities | 1 | 4368 | Risk Ratio (M-H, Fixed, 95% CI) | 1.11 [0.75, 1.66] |
| 7 True mosaics | 1 | 4368 | Risk Ratio (M-H, Fixed, 95% CI) | 1.00 [0.25, 4.00] |
| 9 Maternal contamination | 1 | 4368 | Risk Ratio (M-H, Fixed, 95% CI) | 2.00 [0.37, 10.92] |
| 11 False negative chromosomal diagnosis | 1 | Risk Ratio (M-H, Fixed, 95% CI) | Subtotals only | |
| 11.1 False negative chromosomal results (excluding sex determination) | 1 | 4368 | Risk Ratio (M-H, Fixed, 95% CI) | 3.00 [0.12, 73.67] |
| 11.2 Incorrect sex determination | 1 | 4368 | Risk Ratio (M-H, Fixed, 95% CI) | 5.00 [0.24, 104.18] |
| 12 Reporting time | 1 | 4107 | Mean Difference (IV, Fixed, 95% CI) | 1.20 [0.89, 1.51] |
| 14 Amniotic leakage after test | 1 | 4368 | Risk Ratio (M-H, Fixed, 95% CI) | 2.05 [1.43, 2.94] |
| 20 All known pregnancy loss (including termination of pregnancy) | 1 | 4334 | Risk Ratio (M-H, Fixed, 95% CI) | 1.29 [1.03, 1.61] |
| 21 Termination of pregnancy (all) | 1 | 4334 | Risk Ratio (M-H, Fixed, 95% CI) | 1.26 [0.89, 1.77] |
| 24 Spontaneous miscarriage | 1 | 4334 | Risk Ratio (M-H, Fixed, 95% CI) | 1.41 [1.00, 1.98] |
| 25 Spontaneous miscarriage after test | 1 | 4334 | Risk Ratio (M-H, Fixed, 95% CI) | 3.22 [1.88, 5.53] |
| 27 Stillbirths | 1 | 4334 | Risk Ratio (M-H, Fixed, 95% CI) | 0.73 [0.34, 1.59] |
| 28 Neonatal deaths | 1 | 4334 | Risk Ratio (M-H, Fixed, 95% CI) | 4.98 [0.58, 42.56] |
| 29 All recorded deaths after viability | 1 | 4334 | Risk Ratio (M-H, Fixed, 95% CI) | 1.00 [0.50, 1.99] |
| 30 Anomalies (all recorded) | 1 | 4334 | Risk Ratio (M-H, Fixed, 95% CI) | 1.73 [1.26, 2.38] |
| 31 Talipes | 1 | Risk Ratio (M-H, Fixed, 95% CI) | Subtotals only | |
| 31.1 Talipes (all) | 0 | 0 | Risk Ratio (M-H, Fixed, 95% CI) | Not estimable |
| 31.2 Talipes equinovarus | 1 | 4334 | Risk Ratio (M-H, Fixed, 95% CI) | 14.43 [3.45, 60.41] |