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

Gynaecology and Fertility3 versionsAMSTAR 2: not assessed
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

Show all 3 versions

Antioxidant(s) compared to placebo or no treatment/standard treatment for female subfertility

Population: women with subfertility
6 questions
OutcomeEffectEvidenceStatus / 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]NRVery 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]NRLow
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]NRLow
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]NRLow
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]NRLow
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]NRLow
Downgraded: risk of bias

Head‐to‐head antioxidants for female subfertility

Population: women with subfertility
7 questions
OutcomeEffectEvidenceStatus / 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]NRLow
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]NRVery 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]NRLow
Adverse events ‐ Miscarriage№ of participants: 304(3 RCTs)
OR 1.54 [0.42, 5.67]NRLow
Adverse events ‐ Multiple pregnancy
no estimate extractedNRNo studies
Adverse events ‐ Gastrointestinal disturbances
no estimate extractedNRNo studies
Adverse events ‐ Ectopic pregnancy Melatonin lower dose versus melatonin higher dose№ of participants: 120(1 RCT)
no estimate extractedNRVery low
Downgraded: imprecision