Comparison 2. Antibiotic versus no antibiotic ‐ subgroup by class of antibiotic.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Maternal febrile morbidity/fever	59		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.1 Natural penicillins	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
1.2 Aminopenicillins	7	603	Risk Ratio (M‐H, Fixed, 95% CI)	0.39 [0.26, 0.58]
1.3 Extended spectrum penicillins	6	736	Risk Ratio (M‐H, Fixed, 95% CI)	0.37 [0.28, 0.49]
1.4 Beta‐lactamase inhibitor combinations	5	791	Risk Ratio (M‐H, Fixed, 95% CI)	0.48 [0.29, 0.79]
1.5 First generation cephalosporins	10	1436	Risk Ratio (M‐H, Fixed, 95% CI)	0.54 [0.44, 0.66]
1.6 Second generation cephalosporins	9	1001	Risk Ratio (M‐H, Fixed, 95% CI)	0.35 [0.27, 0.46]
1.7 Cefamycins	9	1894	Risk Ratio (M‐H, Fixed, 95% CI)	0.73 [0.61, 0.88]
1.8 Third generation cephalosporins	3	376	Risk Ratio (M‐H, Fixed, 95% CI)	0.44 [0.27, 0.74]
1.9 Monobactams	1	98	Risk Ratio (M‐H, Fixed, 95% CI)	0.64 [0.29, 1.42]
1.10 Lincosamides	1	30	Risk Ratio (M‐H, Fixed, 95% CI)	0.5 [0.08, 3.05]
1.11 Nitroimidazoles	7	1098	Risk Ratio (M‐H, Fixed, 95% CI)	0.59 [0.48, 0.71]
1.12 Fluoroquinolones	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
1.13 Trimethoprim‐sulfamethoxazole	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
1.14 Aminoglycoside‐containing combination	5	668	Risk Ratio (M‐H, Fixed, 95% CI)	0.33 [0.24, 0.46]
1.15 Other antibiotic combination	4	530	Risk Ratio (M‐H, Fixed, 95% CI)	0.27 [0.17, 0.44]
1.16 Other regimen	1	118	Risk Ratio (M‐H, Fixed, 95% CI)	0.23 [0.07, 0.76]
2 Maternal wound infection	83		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
2.1 Natural penicillins	1	66	Risk Ratio (M‐H, Fixed, 95% CI)	0.43 [0.07, 2.87]
2.2 Aminopenicillins (ampicillin)	12	1323	Risk Ratio (M‐H, Fixed, 95% CI)	0.50 [0.35, 0.72]
2.3 Extended spectrum penicillins	7	845	Risk Ratio (M‐H, Fixed, 95% CI)	0.18 [0.09, 0.39]
2.4 Beta‐lactamase inhibitor combination	6	823	Risk Ratio (M‐H, Fixed, 95% CI)	0.26 [0.13, 0.51]
2.5 First generation cephalosporin	17	3371	Risk Ratio (M‐H, Fixed, 95% CI)	0.38 [0.28, 0.53]
2.6 Second generation cephalosporin	9	1166	Risk Ratio (M‐H, Fixed, 95% CI)	0.38 [0.19, 0.75]
2.7 Cefamycins	16	2635	Risk Ratio (M‐H, Fixed, 95% CI)	0.45 [0.33, 0.60]
2.8 Third generation cephalosporin	6	1519	Risk Ratio (M‐H, Fixed, 95% CI)	0.44 [0.26, 0.73]
2.9 Monobactams	1	98	Risk Ratio (M‐H, Fixed, 95% CI)	0.48 [0.05, 5.03]
2.10 Lincosamides	1	30	Risk Ratio (M‐H, Fixed, 95% CI)	0.25 [0.03, 2.44]
2.11 Nitroimidazoles	9	1074	Risk Ratio (M‐H, Fixed, 95% CI)	0.49 [0.34, 0.69]
2.12 Fluoroquinolones	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
2.13 Trimethoprim‐sulfamethoxazole	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
2.14 Aminoglycoside‐containing combination	8	654	Risk Ratio (M‐H, Fixed, 95% CI)	0.17 [0.08, 0.34]
2.15 Other antibiotic combination	4	530	Risk Ratio (M‐H, Fixed, 95% CI)	0.60 [0.36, 1.02]
2.16 Other regimen	2	171	Risk Ratio (M‐H, Fixed, 95% CI)	0.58 [0.15, 2.30]
3 Maternal endometritis	84		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
3.1 Natural penicillins	1	66	Risk Ratio (M‐H, Fixed, 95% CI)	0.19 [0.05, 0.65]
3.2 Aminopenicillins (ampicillin)	10	1108	Risk Ratio (M‐H, Fixed, 95% CI)	0.24 [0.16, 0.38]
3.3 Extended‐spectrum penicillins	9	1164	Risk Ratio (M‐H, Fixed, 95% CI)	0.46 [0.37, 0.58]
3.4 Beta‐lactamase inhibitor combinations	5	788	Risk Ratio (M‐H, Fixed, 95% CI)	0.67 [0.27, 1.66]
3.5 First generation cephalosporin	18	3451	Risk Ratio (M‐H, Fixed, 95% CI)	0.42 [0.33, 0.54]
3.6 Second generation cephalosporin	13	1563	Risk Ratio (M‐H, Fixed, 95% CI)	0.27 [0.20, 0.37]
3.7 Cefamycins	15	2535	Risk Ratio (M‐H, Fixed, 95% CI)	0.36 [0.28, 0.47]
3.8 Third generation cephalosporin	4	408	Risk Ratio (M‐H, Fixed, 95% CI)	0.28 [0.11, 0.69]
3.9 Monobactams	1	98	Risk Ratio (M‐H, Fixed, 95% CI)	0.63 [0.25, 1.54]
3.10 Lincosamides	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
3.11 Nitroimidazoles	8	919	Risk Ratio (M‐H, Fixed, 95% CI)	0.52 [0.37, 0.73]
3.12 Fluoroquinolones	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
3.13 Trimethoprim‐sulfamethoxazole	1	57	Risk Ratio (M‐H, Fixed, 95% CI)	0.45 [0.20, 1.01]
3.14 Aminoglycoside‐containing combination	8	722	Risk Ratio (M‐H, Fixed, 95% CI)	0.29 [0.19, 0.45]
3.15 Other antibiotic combination	4	530	Risk Ratio (M‐H, Fixed, 95% CI)	0.33 [0.14, 0.75]
3.16 Other regimen	2	171	Risk Ratio (M‐H, Fixed, 95% CI)	0.42 [0.17, 1.03]
4 Maternal serious infectious complications	34		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
4.1 Natural penicillins	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
4.2 Aminopenicillins (ampicillin)	4	542	Risk Ratio (M‐H, Fixed, 95% CI)	0.27 [0.06, 1.18]
4.3 Extended‐spectrum penicillins	1	151	Risk Ratio (M‐H, Fixed, 95% CI)	0.49 [0.05, 5.33]
4.4 Beta‐lactamase inhibitor combinations	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
4.5 First generation cephalosporin	10	2351	Risk Ratio (M‐H, Fixed, 95% CI)	0.39 [0.16, 0.95]
4.6 Second generation cephalosporin	5	522	Risk Ratio (M‐H, Fixed, 95% CI)	0.34 [0.06, 2.13]
4.7 Cefamycins	10	1372	Risk Ratio (M‐H, Fixed, 95% CI)	0.22 [0.10, 0.49]
4.8 Third generation cephalosporin	3	376	Risk Ratio (M‐H, Fixed, 95% CI)	0.70 [0.12, 4.03]
4.9 Monobactams	1	98	Risk Ratio (M‐H, Fixed, 95% CI)	1.25 [0.06, 25.02]
4.10 Lincosamides	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
4.11 Nitroimidazoles	3	516	Risk Ratio (M‐H, Fixed, 95% CI)	0.47 [0.13, 1.65]
4.12 Fluoroquinolones	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
4.13 Trimethoprim‐sulfamethoxazole	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
4.14 Aminoglycoside‐containing regimens	3	398	Risk Ratio (M‐H, Fixed, 95% CI)	0.32 [0.06, 1.59]
4.15 Other antibiotic combination	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
4.16 Other regimen	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
5 Maternal urinary tract infection	67		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
5.1 Natural penicillins	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
5.2 Aminopenicillins (ampicillin)	9	1039	Risk Ratio (M‐H, Fixed, 95% CI)	0.60 [0.41, 0.90]
5.3 Extended‐spectrum penicillin	6	571	Risk Ratio (M‐H, Fixed, 95% CI)	0.34 [0.20, 0.58]
5.4 Beta‐lactamse inhibitor combination	5	788	Risk Ratio (M‐H, Fixed, 95% CI)	0.64 [0.41, 0.99]
5.5 First generation cephalosporin	17	3371	Risk Ratio (M‐H, Fixed, 95% CI)	0.67 [0.49, 0.93]
5.6 Second generation cephalosporin	9	1166	Risk Ratio (M‐H, Fixed, 95% CI)	0.58 [0.38, 0.89]
5.7 Cefamycins	14	2434	Risk Ratio (M‐H, Fixed, 95% CI)	0.73 [0.54, 1.00]
5.8 Third generation cephalosporin	3	308	Risk Ratio (M‐H, Fixed, 95% CI)	0.29 [0.04, 2.16]
5.9 Monobactams	1	98	Risk Ratio (M‐H, Fixed, 95% CI)	1.44 [0.35, 5.91]
5.10 Lincosamides	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
5.11 Nitroimidazoles	5	622	Risk Ratio (M‐H, Fixed, 95% CI)	1.03 [0.53, 2.01]
5.12 Fluoroquinolones	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
5.13 Trimethoprim‐sulfamethoxazole	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
5.14 Aminoglycoside‐containing combination	5	266	Risk Ratio (M‐H, Fixed, 95% CI)	0.30 [0.15, 0.60]
5.15 Other antibiotic combination	2	237	Risk Ratio (M‐H, Fixed, 95% CI)	0.57 [0.32, 1.03]
5.16 Other regimen	2	171	Risk Ratio (M‐H, Fixed, 95% CI)	0.16 [0.02, 1.29]
6 Maternal adverse effects	12		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
6.1 Natural penicillins	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.2 Aminopenisillins (ampicillin)	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.3 Extended‐spectrum penicillins	1	139	Risk Ratio (M‐H, Fixed, 95% CI)	2.96 [0.12, 71.38]
6.4 Beta‐lactamase inhibitor combination	2	235	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.5 First generation cephalosporin	3	507	Risk Ratio (M‐H, Fixed, 95% CI)	0.37 [0.15, 0.90]
6.6 Second generation cephalosporin	1	60	Risk Ratio (M‐H, Fixed, 95% CI)	1.54 [0.07, 36.11]
6.7 Cefamycins	5	654	Risk Ratio (M‐H, Fixed, 95% CI)	1.96 [0.41, 9.34]
6.8 Third generation cephalosporin	1	99	Risk Ratio (M‐H, Fixed, 95% CI)	2.94 [0.12, 70.50]
6.9 Monobactams	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.10 Lincosamides	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.11 Nitroimidazoles	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.12 Fluoroquinolones	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.13 Trimethoprim‐sulfamethoxazole	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.14 Amimnoglycoside‐containing combination	1	80	Risk Ratio (M‐H, Fixed, 95% CI)	3.0 [0.13, 71.51]
6.15 Other antibiotic combination	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.16 Other regimen	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
7 Maternal days in hospital	19		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
7.1 Natural penicillins	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.2 Aminopenicillins (ampicillin)	2	191	Mean Difference (IV, Fixed, 95% CI)	‐0.82 [‐1.33, ‐0.31]
7.3 Extended‐spectrum penicillins	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.4 Beta‐lactamase inhibitor combinations	3	555	Mean Difference (IV, Fixed, 95% CI)	‐0.18 [‐0.46, 0.09]
7.5 First generation cephalosporins	2	325	Mean Difference (IV, Fixed, 95% CI)	‐0.22 [‐0.58, 0.14]
7.6 Second generation cephalosporin	2	220	Mean Difference (IV, Fixed, 95% CI)	‐0.38 [‐0.69, ‐0.08]
7.7 Cefamycins	6	1392	Mean Difference (IV, Fixed, 95% CI)	‐0.37 [‐0.60, ‐0.15]
7.8 Third generation cephalosporin	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.9 Monobactams	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.10 Lincosamides	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.11 Nitroimidazoles	4	485	Mean Difference (IV, Fixed, 95% CI)	‐0.91 [‐1.37, ‐0.45]
7.12 Fluoroquinolones	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.13 Aminoglycoside‐containing combination	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.14 Other antibiotic combination	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.15 Trimethoprim‐sulfamethoxazole	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.16 Other regimen	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]