Summary of findings 2. IVF compared with unstimulated IUI for unexplained subfertility.
| IVF compared with unstimulated IUI for unexplained subfertility | ||||||
| Population: women with unexplained subfertility Setting: fertility clinic Intervention: IVF Comparison: unstimulated IUI | ||||||
| Outcomes | Plain language summary | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Quality of the evidence (GRADE) | |
| Assumed risk | Corresponding risk | |||||
| Unstimulated IUI | IVF | |||||
| Live birth rate IVF vs IUI | Evidence suggests that IVF may result in more births than insemination without using fertility drugs | 160 per 1000 | 320 per 1000 (185 to 494) | OR 2.47 (1.19 to 5.12) | 156 (2 studies) | ⊕⊕⊝⊝ Lowa |
|
Pregnancy rate IVF vs IUI |
It is unclear whether there is a difference in the pregnancy rate resulting from IVF compared with insemination without using fertility drugs, due to insufficient evidence | 121 per 1000 | 400 per 1000 (115 to 775) | OR 4.83 (0.94 to 24.95) | 43 (1 study) | ⊕⊕⊝⊝ Very lowb |
| Multiple pregnancy rate | It is unclear whether there is a difference in the multiple pregnancy rate resulting from IVF compared with insemination without using fertility drugs, due to insufficient evidence | 30 per 1000 | 31 per 1000 (1 to 460) | OR 1.03 (0.04 to 27.29) | 43 (1 study) | ⊕⊝⊝⊝ Very lowc |
| *The basis for the assumed risk is the median control group risk across studies. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; IUI: Intrauterine insemination; OR: Odds ratio. | ||||||
| GRADE Working Group grades of evidence. High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
aThe GRADE quality rating was downgraded by 2 levels due to serious imprecision: There were only 44 events. There was also substantial statistical heterogeneity (I2=60%), though the direction of effect was consistent. bThe GRADE quality rating was downgraded by 3 levels due to very serious imprecision, with only 8 events. The confidence interval is compatible with no difference between the groups or with a large benefit in the IVF group.
cThe GRADE quality rating was downgraded by 3 levels due to very serious imprecision: there was only one event in this analysis