title: The influence of the depth of embryo replacement into the uterine cavity on in vitro fertilization outcome.
abstract: OBJECTIVE
  The aim of our study was to investigate the influence of the depth of embryo replacement into the uterine cavity on the implantation rate after embryo transfer carried out under transabdominal ultrasound guidance.
  
  
  METHODS
  This was a prospective observational study at the St Lazar Hospital, Skopje; spisan patients with an indication for IVF or ICSI according to departmental protocol underwent controlled ovarian hyperstimulation followed by IVF/ICSI and embryo transfer. The highest quality embryos were selected for transfer, with quality being assessed based on cell number and number of cytoplasmic fragments. On the day od ET under direct transabdominal ultrasound guidance, the transfer catheter was advanced through the endocervical canal into the lower uterine segment. Immediate identification of the catheter tip was essential to minimize motion of the catheter and avoid any impact on the endometrium. The transfer catheter then was advanced to a defined distance from the uterine fundus, up to the point estimated for transfer: 10 +/- 2.5 mm and 15 +/- 2.5 mm respectively in A and B group. This measurement was verified by using the calipers prior to injection of the embryos.
  
  
  RESULTS
  In total, 106 patients, aged 24-42 years were included in the study. The patients were divided into two groups according to the distance between the tip of the catheter and the uterine fundus at the time of embryo deposition in the cavity: group A: 10 +/- 2.5 mm; group B: 15 +/- 2.5 mm. Of the patients studied, 47.16% were less than 35 years old, with only 11.3%% more than age 40 years. The majority (66.9%) of patients had either none or one previous transfer. In only 3.7% transfers was blood noted on the catheter tip; and 77.4% of transfers were rated as easy compared to 5.6% rated as difficult. The remaining transfers were moderately difficult. The mean number of embryos transferred per cycle was 2.32. A mean E2 levels on HCG day was 2120 pg/ml. Overall clinical pregnancy were 37.7%. There were not significantly differences between the two groups in term of embryo transfer characteristics (full bladder, ease of transfer, use of tenaculum, bleeding). Our results show that there was not significantly differences between two groups in term of gonadotropin ampoules administered (30 +/- 12.2 in group A vs. 3633 + 868 in group B); Estradiol levels on the day of HCG day (1897 + 761 in group A vs 29.2 +/- 10.8 in group B), mean of oocytes retrieval and embryo transferred ( ET) (8.5 + 6.7 vs 10.9 +/- 6.9; 1.9 +/- 1.1 vs 2.3 +/- 1.2 respectively in group A and B), and grade of ET. Analysis of our results demonstrated that pregnancy rate is significantly influenced by transfer distance from the fundus where the pregnancy rate decreases from 46.2% in group B to 28.8% in group A (p < 0.05). There was not significantly difference in abortion rate between the two groups.
  
  
  CONCLUSIONS
  In conclusion, our results suggest that depth of embryo replacement inside the uterine cavity may influence the pregnancy rates and should be considered as an important factor to improve the success of IVF cycles.
authors.affiliation: Department of Human reproduction, St. Lazar Hospital - Skopje, R. Macedonia.
authors.forename: M
authors.initials: M
authors.lastname: Ivanovski
authors.forename: N
authors.initials: N
authors.lastname: Damcevski
authors.forename: B
authors.initials: B
authors.lastname: Radevska
authors.forename: G
authors.initials: G
authors.lastname: Doicev
mesh_terms: D000328:Adult; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D010062:Ovulation Induction; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic; D014463:Ultrasonography; D014599:Uterus / Q000000981:diagnostic imaging*; D055815:Young Adult