Cochrane · systematic review · CD007807
Antioxidants for female subfertility
Showell, MG, Mackenzie-Proctor, R, Jordan, V, et al. · Cochrane Database of Systematic Reviews · 2020 · Cochrane Library
SoF tableOnly the outcomes this review put in its Summary of Findings table are listed (the Cochrane Handbook caps them at about seven per comparison). Its other analyses are not shown here.
Questions
13
current version
GRADE rated
11
No studies
2
Included studies
NR
No studies 2 · 15.4%Ungraded 0 · 0%Very low 3 · 23.1%Low 8 · 61.5%Moderate 0 · 0%High 0 · 0%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
Questions and results
Current version onlyAntioxidant(s) compared to placebo or no treatment/standard treatment for female subfertility
Population: women with subfertility
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Live birth; antioxidants vs placebo or no treatment/standard treatment (natural conceptions and undergoing fertility treatments)№ of participants: 1227(13 RCTs) Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1.81 [1.36, 2.43] | NR | Very low Downgraded: risk of bias, inconsistency |
Clinical pregnancy; antioxidants vs placebo or no treatment/standard treatment (natural conceptions and undergoing fertility treatments)№ of participants: 5165(35 RCTs) Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1.65 [1.43, 1.89] | NR | Low Downgraded: risk of bias, inconsistency |
Adverse events ‐ Miscarriage№ of participants: 3229(24 RCTs) Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1.13 [0.82, 1.55] | NR | Low Downgraded: risk of bias |
Adverse events ‐ Multiple pregnancy№ of participants: 1886(9 RCTs) Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1 [0.63, 1.56] | NR | Low Downgraded: risk of bias |
Adverse events ‐ Gastrointestinal disturbances№ of participants: 343(3 RCTs) Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1.55 [0.47, 5.1] | NR | Low Downgraded: risk of bias |
Adverse events ‐ Ectopic pregnancy№ of participants: 404(4 RCTs) Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1.4 [0.27, 7.2] | NR | Low Downgraded: risk of bias |
Head‐to‐head antioxidants for female subfertility
Population: women with subfertility
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Live birth; type of antioxidant (natural conceptions and undergoing fertility treatments) ‐ Melatonin lower dose versus melatonin higher dose№ of participants: 140(2 RCTs) | OR 0.94 [0.41, 2.15] | NR | Low |
Clinical pregnancy; type of antioxidant (natural conceptions and undergoing fertility treatments) ‐ N‐acetylcysteine versus L‐carnitine№ of participants: 164(1 RCT) | OR 0.81 [0.33, 2] | NR | Very low Downgraded: imprecision |
Clinical pregnancy; type of antioxidant (natural conceptions and undergoing fertility treatments) ‐ Melatonin lower dose versus melatonin higher dose№ of participants: 140(2 RCTs) | OR 0.94 [0.41, 2.15] | NR | Low |
Adverse events ‐ Miscarriage№ of participants: 304(3 RCTs) | OR 1.54 [0.42, 5.67] | NR | Low |
Adverse events ‐ Multiple pregnancy | no estimate extracted | NR | No studies |
Adverse events ‐ Gastrointestinal disturbances | no estimate extracted | NR | No studies |
Adverse events ‐ Ectopic pregnancy Melatonin lower dose versus melatonin higher dose№ of participants: 120(1 RCT) | no estimate extracted | NR | Very low Downgraded: imprecision |
Antioxidant(s) compared to placebo or no treatment/standard treatment for female subfertility
Population: subfertile women who had been referred to a fertility clinic and might or might not be undergoing assisted reproductive techniques
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Live birth; antioxidants vs placebo or no treatment/standard treatment (natural conceptions and undergoing fertility treatments) Antioxidant(s) vs placebo or no treatment/standard treatment | OR 2.13 [1.45, 3.12] | 8 studies · 651 participants | Very low Downgraded: risk of bias |
Clinical pregnancy; antioxidants vs placebo or no treatment/standard treatment (natural conceptions and undergoing fertility treatments) Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1.52 [1.31, 1.76] | 26 studies · 4271 participants | Very low Downgraded: risk of bias |
Adverse events ‐ Miscarriage Antioxidant(s) vs placebo or no treatment/standard treatment | OR 0.79 [0.58, 1.08] | 18 studies · 2834 participants | Very low Downgraded: risk of bias |
Adverse events ‐ Multiple pregnancy Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1 [0.73, 1.38] | 8 studies · 2163 participants | Very low Downgraded: risk of bias |
Adverse events ‐ Gastrointestinal disturbances Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1.55 [0.47, 5.1] | 3 studies · 343 participants | Very low Downgraded: risk of bias |
Pentoxifylline compared to placebo or no treatment/standard care for female subfertility
Population: subfertile women who had been referred to a fertility clinic and might or might not be undergoing assisted reproductive techniques
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Live birth; pentoxifylline vs placebo or no treatment/standard treatment (natural conceptions and undergoing fertility treatments) Pentoxifylline vs placebo or no treatment/standard care | OR 1.54 [0.68, 3.5] | 1 study · 112 participants | Very low Downgraded: indirectness |
Clinical pregnancy; pentoxifylline vs placebo or no treatment/standard treatment (natural conceptions and undergoing fertility treatments) Pentoxifylline vs placebo or no treatment/standard care | OR 2.07 [1.2, 3.56] | 3 studies · 276 participants | Very low Downgraded: risk of bias, imprecision, indirectness |
Adverse events ‐ Miscarriage Pentoxifylline vs placebo or no treatment/standard care | OR 1.34 [0.46, 3.9] | 3 studies · 276 participants | Very low Downgraded: risk of bias, imprecision, indirectness |
Adverse events ‐ Multiple pregnancy Pentoxifylline vs placebo or no treatment/standard care | OR 0.78 [0.2, 3.09] | 1 study · 112 participants | Very low Downgraded: indirectness |
Adverse events ‐ Gastrointestinal disturbances Pentoxifylline vs placebo or no treatment/standard care | no estimate extracted | NR | No studies |
Antioxidant(s) versus placebo or no treatment/standard treatment for female subfertility
Population: Subfertile women
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Live birth; antioxidants vs placebo or no treatment/standard treatment (natural conceptions and undergoing fertility treatments) Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1.25 [0.19, 8.26] | 2 studies · 97 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Clinical pregnancy; antioxidants vs placebo or no treatment/standard treatment (natural conceptions and undergoing fertility treatments) Antioxidant(s) vs placebo or no treatment/standard treatment | OR 1.3 [0.92, 1.85] | 13 studies · 2441 participants | Very low Downgraded: risk of bias, imprecision, inconsistency |
Adverse events ‐ Miscarriage Antioxidant(s) vs placebo or no treatment/standard treatment | OR 0.88 [0.57, 1.36] | 8 studies · 1456 participants | Low Downgraded: risk of bias, imprecision |
Adverse events ‐ Multiple pregnancy Antioxidant(s) vs placebo or no treatment/standard treatment | OR 0.7 [0.41, 1.21] | 2 studies · 1022 participants | Low Downgraded: risk of bias |