title: Letrozole versus clomiphene citrate in polycystic ovary syndrome: systematic review and meta-analysis.
abstract: The objective of the present systematic review and meta-analysis was to examine the literature and to identify the results of randomized controlled trials (RCTs) comparing the use of letrozole to clomiphene citrate (CC) for ovulation induction in patients with polycystic ovary syndrome (PCOS). An exhaustive electronic literature search was performed using the MEDLINE and EMBASE databases until October 2014. Seven prospective RCTs comparing the use of letrozole to CC in PCOS patients met the inclusion criteria. Overall, the seven included studies accounted for 1833 patients (906 in the letrozole group and 927 in the CC group) and for 4999 ovulation induction cycles (2455 in the letrozole group and 2544 in the CC group). Five of the included studies reported data on live birth rates. There was a statistically significant increase in the live birth and pregnancy rates in the letrozole group when compared to the CC group, with a relative risk (RR) = 1.55 (95% confidence interval (CI): 1.26-1.90; I(2) = 0%) and RR = 1.38 (95% CI: 1.05-1.83; I(2) = 61%), respectively. There were no differences in the multiple pregnancy, miscarriage and ovulation rates between the two groups. Our study found that letrozole is superior to CC when considering the live birth and pregnancy rates in patients with PCOS.
authors.affiliation: a Origen-Center for Reproductive Medicine, Av Rodolfo de Amoedo , 140, Barra da Tijuca , Rio de Janeiro , Brazil .
authors.forename: Matheus
authors.initials: M
authors.lastname: Roque
authors.affiliation: a Origen-Center for Reproductive Medicine, Av Rodolfo de Amoedo , 140, Barra da Tijuca , Rio de Janeiro , Brazil .
authors.forename: Ana C I
authors.initials: AC
authors.lastname: Tostes
authors.affiliation: a Origen-Center for Reproductive Medicine, Av Rodolfo de Amoedo , 140, Barra da Tijuca , Rio de Janeiro , Brazil .
authors.forename: Marcello
authors.initials: M
authors.lastname: Valle
authors.affiliation: b Origen-Center for Reproductive Medicine, Av do Contorno , 7747, Lourdes , Belo Horizonte , Brazil , and.
authors.forename: Marcos
authors.initials: M
authors.lastname: Sampaio
authors.affiliation: b Origen-Center for Reproductive Medicine, Av do Contorno , 7747, Lourdes , Belo Horizonte , Brazil , and.|c Universidade Federal de Minas Gerais, Avenida Alfredo Balena , 190, Belo Horizonte , Brazil.
authors.forename: Selmo
authors.initials: S
authors.lastname: Geber
mesh_terms: D047072:Aromatase Inhibitors / Q000627:therapeutic use; D002996:Clomiphene / Q000627:therapeutic use*; D005260:Female; D005300:Fertility Agents, Female / Q000627:therapeutic use; D006801:Humans; D007247:Infertility, Female / Q000209:etiology / Q000628:therapy*; D000077289:Letrozole; D050498:Live Birth; D016239:MEDLINE; D009570:Nitriles / Q000627:therapeutic use*; D010062:Ovulation Induction / Q000379:methods*; D011085:Polycystic Ovary Syndrome / Q000150:complications*; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D014230:Triazoles / Q000627:therapeutic use*
chemical_list: D047072:Aromatase Inhibitors; D005300:Fertility Agents, Female; D009570:Nitriles; D014230:Triazoles; D002996:Clomiphene; D000077289:Letrozole
keywords: Clomiphene citrate; PCOS; letrozole