Table 1.
Design and characteristics of studies included in the meta-analysis.
| Study, Year | Design | Intervention | Control | Gestational Age | Age (Mean) | Nullipara | Cervical Dilatation |
|---|---|---|---|---|---|---|---|
| Bidgood, 1987 [15] | RCT | high dose (19) | low dose (21) | >34 weeks | NI | NI | <0.5 cm/h |
| Frigoletto, 1995 [16] | RCT | high dose (678) | low dose (585) | ≥36 weeks | NI | I: 678 (100%) C:585 (100%) |
I: 3.3 ± 2.0 C: 3.6 ± 2.1 |
| Hourvitz, 1996 [17] | RCT | high dose (83) | low dose (65) | I: 41.0 ± 51.5 C: 40.7 ± 1.5 |
I: 28.4 ± 5.0 C: 28.7 ± 5.4 |
I: 47 (56.1%) C:34 (51.9%) |
I: 1.8 ± 0.9 C: 1.7 ± 0.9 |
| Jamal, 2004 [18] | RCT | high dose (100) | low dose (100) | I: 39.1 ± 1.3 C: 38.0 ± 1.3 |
I: 25.4 ± 4.9 C: 26.3 ± 5.1 |
I: 50 (50%) C:41 (41%) |
I: 3.5 ± 0.7 C: 3.7 ± 0.7 |
| Kenyon, 2013 [19] | RCT | high dose (47) | low dose (47) | ≥37 weeks | NI | I: 47 (100%) C:47 (100%) |
>4 cm |
| Liu, 2018 [20] | RCT | high dose (324) | low dose (162) | I: 278 ± 4 days C: 281 ± 5 days |
I: 25.53 ± 2.46 C: 25.46 ± 1.95 |
I: 138 (85%) C:142 (88%) |
>28 mm |
| Majoko, 2001 [21] | RCT | high dose (125) | low dose (133) | I: 39.2 ± 2.1 C: 39.7 ± 2.1 |
I: 20.2 ± 3.3 C: 20.4 ± 3.5 |
I: 125 (100%) C:133 (100%) |
I: 6.0 ± 1.6 C: 6.3 ± 1.7 |
| Manjula, 2015 [22] | RCT | high dose (100) | low dose (100) | I: 38.2 ± 1.07 C: 38.0 ± 1.11 |
I: 26.0 ± 3.4 C: 26.2 ± 3.7 |
I: 65 (65%) C:63 (63%) |
≥3 cm |
| Merril, 1999 [23] | double-blind RCT | high dose (249) | low dose (242) | I: 39.1 ± 0.1 C: 38.9 ± 0.1 |
I: 25.4 ± 0.4 C: 25.4 ± 0.4 |
I: 135 (54.2%) C:115 (47.5%) |
I: 4.7 ± 0.1 C: 5.0 ± 0.1 |
| Muller, 1992 [24] | RCT | high dose (70) | low dose (68) | I: 40.5 ± 1.6 C: 40.6 ± 1.5 |
I: 22.7 ± 5.7 C: 22.3 ± 5.3 |
I: 46 (65.7%) C:45 (66.2%) |
I: 1.7 ± 1.1 C:1.8 ± 1.1 |
| NCT, 2022 [25] | RCT | high dose (10) | low dose (10) | 38.7 ± 1.85 | 26.2 ± 5.26 | NI | NI |
| Neerukonda, 2018 [26] | RCT | high dose (200) | low dose (200) | I: 38.9 ± 0.88 C: 39.0 ± 0.86 |
I: 24.1 ± 3.5 C: 24.4 ± 3.2 |
I: 98 (49%) C:98 (49%) |
NI |
| Padmaja, 2022 [27] | RCT | high dose (90) | low dose (90) | I: 38.6 ± 2.5 C: 38.1 ± 1.2 |
I: 25.0 ± 4.0 C: 24.7 ± 4.1 |
I: 90 (100%) C:90 (100%) |
≥3 cm |
| Prichard, 2019 [28] | retrospective | high dose (2674) | low dose (2211) | I: 39.9 ± 1.30 C: 39.7 ± 1.30 |
I: 30.3 ± 4.7 C: 30.7 ± 4.6 |
I: 2674 (100%) C:2211 (100%) |
I: 645 (29.2%) C: 1016 (38%) |
| Selin, 2019 [29] | RCT | high dose (647) | low dose (648) | I: 29.9 ± 4.8 C: 29.9 ± 4.6 |
I: 29.0 ± 4.8 C: 29.0 ± 4.6 |
I: 647 (100%) C:648 (100%) |
I: 3.47 ± 1.55 C: 3.50 ± 1.60 |
| Satin, 1992 [30] | RCT | high dose (1537) | low dose (1252) | I: 39.0 0 ± 0.1 C: 39.0 0 ± 0.1 |
I: 22.7 0 ± 0.2 C: 22.9 ± 0.2 |
I: 938 (61%) C:751 (60%) |
≥3 cm I: 48% C:47% |
| Son, 2020 [31] | double-blind RCT | high dose (502) | standard dose (501) | I: 39.1 ± 0.8 C: 39.1 ± 0.7 |
I: 31.5 ± 4.4 C: 31.7 ± 4.3 |
I: 502 (100%) C:501 (100%) |
≥3 cm |
| Tesemma, 2020 [32] | cross-sectional | high dose (108) | low dose (108) | 39.4 weeks | 26 years | I: 56 (51.9%) C:32 (29.6%) |
≥4 cm |
| Toaff, 1978 [33] | prospective | pharmacological dose (134) | physiological dose (144) | I: 39.51 ± 0.95 C: 43.62 ± 4.27 |
I: 24- 1 ± 2.5 C: 23.2 ± 2.3 |
I: 64 (47.74%) C:62 (43.06%) |
NI |
| Wei, 2022 [34] | double-blind RCT | high dose (70) | low dose (70) | ≥37 weeks | I: 27.67 ± 4.86 C: 29.73 ± 5.54 |
I: 21 (30%) C:22 (31.43%) |
NI |
| Xenakis, 1995 [35] | RCT | high dose (154) | low dose (156) | I: 40.2 ± 1.6 C: 39.9 ± 2.0 |
I: 24.4 ± 5.9 C: 24.2 ± 6.9 |
I: 72 (46.75%) C:94 (60.26%) |
I: 5.4 cm C: 6.2 cm |
I: intervention; C: control; NI: not informed. Values in mean ± SD or n (%).