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Evidence summaries

Aromatase Inhibitors (Letrozole) for Infertile Women with Polycystic Ovary Syndrome

Letrozole improves live birth compared to clomiphene citrate (a selective oestrogen receptor modulator, SERM) in infertile women with anovulatory polycystic ovary syndrome, without increasing ovarian hyperstimulation syndrome or miscarriage rates. Level of evidence: "A"

Summary

A Cochrane review [Abstract] 3 included 41 studies with a total of 6522 subjects. Polycystic ovary syndrome (PCOS) is the most common cause of oligomenorrhoea and amenorrhoea. Live birth rates were higher with letrozole (with or without adjuncts) compared to clomiphene citrate (a selective oestrogen receptor modulator, SERM) with our without adjuncts followed by timed intercourse (table T2); number needed to treat (NNT) for an additional beneficial outcome 10.

Letrozole compared to clomifen (SERM) for infertile women with PCOS

OutcomeRelative effect(95% CI)Risk with control - SERMRisk with intervention - letrozole (95% CI)No of participants(studies)Certainty of evidence
Live birth rateOR 1.72(1.40 to 2.11)204 per 1000307 per 1000(265 to 352)2060 (11) High
Ovarian hyperstimulation syndrome rateRD -0.00(−0.01 to 0.01)7 per 10005 per 1000(5 to 5)1848(10) High
Miscarriage rate by pregnanciesOR 0.94(0.66 to 1.32)252 per 1000240 per 1000(182 to 307)736(15) High
Multiple pregnancy rateOR 0.74(0.42 to 1.32)22 per 100016 per 1000(9 to 28)2247(14) High

Clinical comments

Note

Date of latest search:2023-03-08

    References

    • Franik S, Le QK, Kremer JA et al. Aromatase inhibitors (letrozole) for ovulation induction in infertile women with polycystic ovary syndrome. Cochrane Database Syst Rev 2022;9(9):CD010287. [PubMed]

Primary/Secondary Keywords