Summary of findings 3. Oestrogen compared to no pretreatment for ovarian stimulation protocols for women undergoing assisted reproductive techniques.
| Oestrogencompared to no pretreatment for ovarian stimulation protocols for women undergoing assisted reproductive techniques | ||||||
|
Patient or population: ovarian stimulation protocols for women undergoing ART Settings: Intervention: oestrogen Comparison: no pretreatment | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk1 | Corresponding risk | |||||
| No pretreatment | Oestr | |||||
|
Live birth or ongoing pregnancy (Oestr + Ant vs Ant) |
299 per 1000 | 252 per 1000 (184 to 333) | OR 0.79 (0.53 to 1.17) | 502 (2 studies) | ⊕⊕⊕⊝ Moderate2 | ‐ |
|
Live birth or ongoing pregnancy (Oestr + Ant vs Ag) |
350 per 1000 | 322 per 1000 (215 to 447) | OR 0.88 (0.51 to 1.5) | 242 (2 studies) | ⊕⊝⊝⊝ Very low3,4 | ‐ |
|
Pregnancy loss (Oestr + Ant vs Ant) |
208 per 1000 | 40 per 1000 (5 to 279) | OR 0.16 (0.02 to 1.47) | 49 (1 study) | ⊕⊝⊝⊝ Very low3,4 | ‐ |
|
Pregnancy loss (Oestr + Ant vs Ag) |
72 per 1000 | 110 per 1000 (46 to 240) | OR 1.59 (0.62 to 4.06) | 220 (1 study) | ⊕⊝⊝⊝ Very low3,4 | ‐ |
|
Multiple pregnancy rate (Oestr + Ant vs Ant) |
No data available | ‐ | ‐ | |||
|
Multiple pregnancy rate (Oestr + Ant vs Ag) |
Not calculable ‐ see comment | OR 2.24 (0.09 to 53.59) | 22 (1 study) | ⊕⊝⊝⊝ Very low3,4 | Only 2 events (both in oestrogen group) | |
|
OHSS rate (Oestr + Ant vs Ant) |
No data available | ‐ | ‐ | |||
|
OHSS rate (Oestr + Ant vs Ag) |
18 per 1000 | 27 per 1000 (5 to 147) |
OR 1.54 (0.25 to 9.42) |
220 (1 study) |
⊕⊝⊝⊝ Very low3,4 | ‐ |
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. 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). Ag: agonist; Ant: antagonist; ART: assisted reproductive techniques; CI: confidence interval; Oestr: oestrogen; OHSS: ovarian hyperstimulation syndrome; 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. | ||||||
1 Mean baseline risk of control group. 2 Downgraded one level for serious imprecision: effect estimate with wide confidence intervals. 3 Downgraded one level for serious risk of bias due to poor reporting on allocation concealment or high attrition (or both). 4 Downgraded two levels for very serious imprecision: small sample size and effect estimate with wide confidence intervals.