title: Empty Follicle Syndrome: The Possible Cause of Occurrence.
abstract: OBJECTIVE
  Empty follicle syndrome (EFS), although rare, is a disappointing condition in which no oocytes are retrieved from mature follicle after ovulation induction in in vitro fertilization (IVF) cycles. The aim of this study was to estimate the incidence and factors associated with EFS.
  
  
  METHODS
  All cycles resulting in EFS from May 2012 to September 2013 were retrospectively identified at a tertiary referral infertility center. Among the 3,356 cycles performed, 58 (1.7%) women who underwent their first IVF cycle and had no oocyte retrieval were enrolled in the study. Three different stimulation protocols (long, antagonist, and miniflare) were mainly used for induction of follicular growth. Data relating to the age, follicle stimulating hormone (FSH) level, anti-Müllerain hormone (AMH) level, and the number of ampules and follicles for each patient was obtained.
  
  
  RESULTS
  Out of 58 individuals, 10 (17.2%) showed false type and 48 (82.8%) showed genuine EFS. The most frequent findings in our study were diminished ovarian reserve, low anti-Müllerian hormone (AMH; ≤0.5 ng/mL), and less than four mature follicles, indicating EFS in 1.7% of the patients.
  
  
  CONCLUSIONS
  Low serum AMH levels and a small number of follicles after ovarian stimulation is the manifestation of diminished ovarian reserve. Thus, we suggest that EFS could be a manifestation of low ovarian reserve.
authors.affiliation: Department of Endocrinology and Female Infertility, Royan Institute for Reproductive Biomedicine, Tehran, Iran.
authors.forename: Tahereh
authors.initials: T
authors.lastname: Madani
authors.affiliation: Department of Endocrinology and Female Infertility, Royan Institute for Reproductive Biomedicine, Tehran, Iran.
authors.forename: Nadia
authors.initials: N
authors.lastname: Jahangiri
keywords: Fertilization in Vitro; Oocyte Retrieval; Ovarian Reserve; Ovulation Induction