Summary of findings 6. Exposure to gonadotropins for subfertility compared to general population and endometrial cancer risk.

Patient or population: Women treated with ovary‐stimulating drugs for subfertility Intervention: Exposure to gonadotropins for subfertility Comparison: General population
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	№ of participants (studies)	Quality of the evidence (GRADE)	Comments
	Risk with no treatment	Risk with exposure to gonadotropins for subfertility
Endometrial cancer	Study population		RR 2.12 (0.79 to 5.64)	1595 (2 observational studies)	⊕⊝⊝⊝ Very low 1,2,3
	542 per 100,000	1148 per 100,000 (428 to 3054)
*The risk in the intervention group (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; RR: Risk ratio
GRADE Working Group grades of evidence High quality: We are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect

¹ Initial level of evidence was 'low' because of the study design (observational studies).
 ²Downgraded because of risk of bias and imprecision.
 ³ Optimal information size (OIS) not met.