title: Absolute position versus relative position in embryo transfer: a randomized controlled trial.
abstract: BACKGROUND
  Meta-analysis revealed that embryo placement 20 mm from the fundal endometrial surface resulted in higher pregnancy rate, ongoing pregnancy rate, and live birth rate compared with placement 10 mm from the fundal endometrial surface. Pregnancy and implantation rates according to relative position were higher when the catheter tip was positioned close to the middle of the endometrial cavity. The aim of the current study is to evaluate differences in implantation and pregnancy rates if the site of embryo transfer is 2 cm distance from the fundal endometrium (DFE) compared to the midpoint of the endometrial cavity length (ECL).
  
  
  METHODS
  Patients were randomized to one of two groups: in group A (n = 98, 98 IVF-ET cycles), the embryo transfer catheter tip was positioned 2 cm DFE, while that in group B (n = 97, 97 IVF-ET cycles) was positioned at the midpoint of the ECL. We compared pregnancy outcomes of implantation rate, chemical pregnancy rate, clinical pregnancy rate, ongoing pregnancy rate, ectopic pregnancy rate, and miscarriage rate in the two groups.
  
  
  RESULTS
  Analysis of implantation rate (19.5 ± 27.7 vs. 21.7 ± 32.6; p = 0.6), chemical pregnancy rate (51 % vs. 50.5 %; p = 0.94), clinical pregnancy rate (35.7 % vs. 38.1 %; p = 0.73), ongoing pregnancy rate (31.6 % vs. 30.9 %; p = 0.92), ectopic pregnancy rate (8.6 % vs. 2.7 %; p = 0.35), and miscarriage rate (11.4 % vs. 16.2 %; 0.74) revealed comparable results for both groups.
  
  
  CONCLUSIONS
  Implantation and pregnancy rates were not influenced by the site of the ET catheter tip being 2 cm DFE compared to at the midpoint of the ECL.
  
  
  BACKGROUND
  
  ISRCTN15972342.
authors.affiliation: Department of Obstetrics and Gynecology, CHA Fertility Center of Bundang CHA General Hospital, CHA University, Seongnam, Korea. khlsm98@dreamwiz.com.|College of Medicine, CHA University and CHA Fertility Center of Bundang CHA General Hospital, 351 Yatap-dong, Bundang-gu, Seongnam, Gyeonggi-do, 463-712, Korea. khlsm98@dreamwiz.com.
authors.forename: Hwang
authors.initials: H
authors.lastname: Kwon
authors.affiliation: Department of Obstetrics and Gynecology, CHA Fertility Center of Bundang CHA General Hospital, CHA University, Seongnam, Korea. artchoi83@medimail.co.kr.
authors.forename: Dong-Hee
authors.initials: DH
authors.lastname: Choi
authors.affiliation: CHA Fertility Center of Bundang CHA General Hospital, CHA University, Seongnam, Korea. magnoly@hanmail.net.
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
mesh_terms: D000022:Abortion, Spontaneous / Q000175:diagnosis*; D000328:Adult; D001723:Birth Rate; D010064:Embryo Implantation / Q000502:physiology*; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D010062:Ovulation Induction / Q000379:methods; D011247:Pregnancy; D018873:Pregnancy Rate