title: Congenital malformations among 911 newborns conceived after infertility treatment with letrozole or clomiphene citrate.
abstract: OBJECTIVE
  To evaluate the incidence of congenital malformations among offspring of mothers who conceived with clomiphene citrate (CC) or with letrozole treatment for infertility.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  5 fertility centers in Canada.
  
  
  METHODS
  911 newborns from women who conceived following CC or letrozole treatment.
  
  
  METHODS
  Examination of medical files of both mother and newborn, and cross-checked with the parents by telephone calls.
  
  
  METHODS
  Identified major and minor congenital malformations, birth weight, age of the mother, and type of treatment that led to the conception.
  
  
  RESULTS
  Overall, congenital malformations and chromosomal abnormalities were found in 14 of 514 newborns in the letrozole group (2.4%) and in 19 of 397 newborns in the CC group (4.8%). The major malformation rate in the letrozole group was 1.2% (6/514) and in the CC group was 3.0% (12/397). One newborn in the letrozole group was found to have a ventricular septal defect (0.2%) compared to 4 newborns in the CC group (1.0%). In addition, the rate of all congenital cardiac anomalies was significantly higher (P: 0.02) in the CC group (1.8%) compared to the letrozole group (0.2%).
  
  
  CONCLUSIONS
  There was no difference in the overall rates of major and minor congenital malformations among newborns from mothers who conceived after letrozole or CC treatments. However, it appears that congenital cardiac anomaly is less frequent in the letrozole group. The concern that letrozole use for ovulation induction could be teratogenic is unfounded based on our data.
authors.affiliation: Department of Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada.
authors.forename: Togas
authors.initials: T
authors.lastname: Tulandi
authors.forename: James
authors.initials: J
authors.lastname: Martin
authors.forename: Raedah
authors.initials: R
authors.lastname: Al-Fadhli
authors.forename: Nadia
authors.initials: N
authors.lastname: Kabli
authors.forename: Rachel
authors.initials: R
authors.lastname: Forman
authors.forename: Jason
authors.initials: J
authors.lastname: Hitkari
authors.forename: Clifford
authors.initials: C
authors.lastname: Librach
authors.forename: Ellen
authors.initials: E
authors.lastname: Greenblatt
authors.forename: Robert F
authors.initials: RF
authors.lastname: Casper
mesh_terms: D000328:Adult; D047072:Aromatase Inhibitors / Q000627:therapeutic use; D002170:Canada / Q000453:epidemiology; D002996:Clomiphene / Q000627:therapeutic use*; D015897:Comorbidity; D000013:Congenital Abnormalities / Q000453:epidemiology*; D005260:Female; D005300:Fertility Agents, Female / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007247:Infertility, Female / Q000188:drug therapy* / Q000453:epidemiology*; D000077289:Letrozole; D009570:Nitriles / Q000627:therapeutic use*; D010062:Ovulation Induction; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016896:Treatment Outcome; D014230:Triazoles / Q000627:therapeutic use*
chemical_list: D047072:Aromatase Inhibitors; D005300:Fertility Agents, Female; D009570:Nitriles; D014230:Triazoles; D002996:Clomiphene; D000077289:Letrozole