title: The effect of administering vaginal estrogen to clomiphene citrate stimulated cycles on endometrial thickness and pregnancy rates in unexplained infertility.
abstract: OBJECTIVE
  Clomiphene citrate (CC) has some negative effects on the endometrium. We aimed to determine the effect of vaginally administered local estrogen (LE) on endometrial thickness (ET) and pregnancy rates in CC stimulated cycles.
  
  
  METHODS
  This was a prospective randomized crossover study that took place in a university hospital. The patients had received CC due to unexplained infertility (UI). Two different treatment protocols were given sequentially as, either CC+LE or CC alone. Each protocol was planned for two cycles and there was a one-month wash-out period between protocols. The effects of LE on the 3(rd) and 9(th) day, the ovulation day (OD) and 7(th) postovulation day (POD7) were investigated.
  
  
  RESULTS
  A total of 6 pregnancies were achieved with 3 patients from each protocol. The ET was 7.6±1.4 mm and 8.3±2.1 mm respectively and significantly different in the CC group and the CC+E2 groups on the OD (p=.039), while these values were 9.7±2.3 mm and 10.9±3.0 mm respectively and significantly different on the POD7 (p=.007). There was no significant difference between the groups for arterial PI values on the OD and POD7. The frequency of thin endometrium (<6 mm) was 15.2% and 12.2% respectively in the CC group and the CC+E2 group on the OD (p=.628) and 5.1% and 1.2% respectively on the POD7 (p=.182).
  
  
  CONCLUSIONS
  Adding vaginal LE to CC stimulated cycles led to a significant increase in ET on the OD and POD7. However, this difference in thickness was not reflected in the pregnancy rates in this study.
authors.affiliation: Department of Gynecology and Obstetrics, Ankara Oncology Education and Research Hospital, Ankara, Turkey.
authors.forename: Kadir
authors.initials: K
authors.lastname: Cetinkaya
authors.affiliation: Department of Gynecology and Obstetrics, Istanbul Medicalpark Hospital, Istanbul, Turkey.
authors.forename: Sedat
authors.initials: S
authors.lastname: Kadanalı
keywords: Infertility; clomiphene citrate; endometrial thickness; estrogen; pregnancy