Comparison 1.

Second trimester amniocentesis versus control

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Not complied with allocated procedure	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	1.73 [1.03, 2.91]
3 Multiple insertions	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	91.08 [5.61, 1477. 53]
4 Second test performed	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	41.04 [2.48, 678.07]
5 Laboratory failure	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	27.02 [1.61, 454.31]
6 All non-mosaic abnormalities	1	4593	Risk Ratio (M-H, Fixed, 95% CI)	30.85 [1.85, 515.31]
13 Vaginal bleeding after test	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	0.95 [0.66, 1.37]
14 Amniotic leakage after test	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	3.90 [1.95, 7.80]
20 All known pregnancy loss (including termination of pregnancy)	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	1.41 [0.99, 2.00]
21 Termination of pregnancy (all)	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	2.50 [0.97, 6.44]
24 Spontaneous miscarriage	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	1.60 [1.02, 2.52]
26 Perinatal deaths	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	0.63 [0.28, 1.38]
27 Stillbirths	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	0.83 [0.36, 1.93]
28 Neonatal deaths	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	0.11 [0.01, 2.06]
29 All recorded deaths after viability	1	4606	Risk Ratio (M-H, Fixed, 95% CI)	0.63 [0.28, 1.38]
30 Anomalies (all recorded)	1	4507	Risk Ratio (M-H, Fixed, 95% CI)	0.93 [0.62, 1.39]
31 Talipes	1	4507	Risk Ratio (M-H, Fixed, 95% CI)	0.68 [0.37, 1.22]
35 Neonatal respiratory distress syndrome	1	4507	Risk Ratio (M-H, Fixed, 95% CI)	2.11 [1.06, 4.19]