Human Reproduction vol 11 no 8 pp 1687-1689, 1996 Incidence of microbial growth from the tip of the embryo transfer catheter after embryo transfer in relation to clinical pregnancy rate following in-vitro fertilization and embryo transfer P.E.Egbase 1 ' 3 , M.Al-Sharhan 1 , S.Al-Othman 1 , M.Al-Mutawa 1 , E.E.Udo 2 and J.G.Grudzinskas 3 - 4 'IVF Centre, Maternity Hospital, 2 Dept of Microbiology, Kuwait University, Kuwait and 3 Academic Unit of Obstetrics & Gynaecology, London Hospital Medical College, London El IBB, UK 4 To whom correspondence should be addressed A total of 110 consecutive women was studied prospectively at the time of transcervical embryo transfer following conventional in-vitro fertilization and intracytoplasmic sperm injection procedures. Microbiological cultures were performed on endocervical swabs and embryo transfer catheter tips. Positive microbial growths were observed from endocervical swabs in 78 (70.9%) women and from catheter tips in 54 (49.1%) women. The clinical pregnancy rates were 57.1 % in the group of patients without growth and 29.6% in the group with positive microbial growth from catheter tips. As microbial contamination at embryo transfer may influence implantation rates, prospective studies are justified to determine whether eradication of endocervical micro-organisms is possible and whether their eradication will improve implantation rates. Key words: embryo transfer/endocervical organisms/transfer catheter Introduction Fertilization rates of 60-70% can currently be expected in established centres from routine insemination in conventional in-vitro fertilization (IVF) performed with samples from normozoospermic males. More recently, similar fertilization rates have been obtained in severe male factor infertility using intracytoplasmic sperm injection (ICSI) (Van Steirteghem et al., 1993; Payne et al, 1994). Using both techniques, morpho- logically healthy looking embryos which may not always be cytogenetically normal have been generated (Plachot et al., 1988). Nevertheless, there has not been a corresponding increase in implantation rates, which have remained at 12-15% (Edwards and Brody, 1995), and this has largely been attributed to confounding variables such as endometrial receptivity and the embryo's potential to implant. Factors implicated in embryonic impairment range from culture conditions, hormone stimulation, gamete immaturity or quality to chromosomal abnormality. An area that has been poorly explored is trans- cervical instrumentation of the endometrial cavity leading to the possibility of bacterial contamination of the uterine cavity. The procedure of embryo transfer has some similarities with © European Society for Human ReproducUon and Embryology hysterosalpingography, and salpingitis following hystero- salpingography is a well recognized complication (Peters et al., 1993). Furthermore, Mark and Paulson (1992) reported a case of severe pelvic infection complicating transcervical embryo transfer in an agonadal woman who had not undergone prior transvaginal oocyte aspiration (donor egg recipient) In this preliminary study, we have examined the possible inoculation of microbial organisms from the endocervical canal to the endometrial cavity, following transcervical embryo transfer in relation to clinical pregnancy rates in 110 women undergoing IVF and embryo transfer. Materials and methods A total of 110 consecutive patients was studied prospectively at the time of the embryo transfer procedure following conventional IVF and ICSI performed from November 1994 to April 1995 at the IVF Centre, Maternity Hospital, Kuwait. Ovanan stimulation was performed commencing pituitary down- regulation in the mid-luteal phase with gonadotrophin-releasing hor- mone agonist (buserehn. Hoechst, West Germany). Pre-stimulation ultrasound scans were performed to confirm down-regulation pnor to which high vaginal and endocervical swabs were taken. Patients with positive growths were treated with appropriate antibiotics Human menopausal gonadotrophin (HMG) and/or highly purified follicle stimulaung hormone was administered for 12-14 days and trans- vaginal ultrasound performed on two or three occasions to monitor folhcular growth, human chononic gonadotrophin (HCG), 10 000 IU being administered when two or more leading follicles were >18 mm. Transvaginal ultrasound-guided ovum retrieval was performed 36 h after administration of HCG and metronidazole (500 mg I.V ) was routinely administered during the procedure. Semen was prepared using the mini-Percoll technique and oocytes and embryos cultured in Earle's balanced salt media supplemented with human serum albumin All embryo transfers were performed by one of the authors using a Wallace catheter (H G Wallace Ltd, UK). Up to four embryos were transferred The loading of the embryos and the transfer procedure were performed with strict aseptic techniques The cervix was exposed with a bivalve speculum and cleansed with gauze swab soaked in Earle's culture medium Pnor to introducing the embryo transfer catheter, two endocervical swabs (wet and dry) were taken. The transfer catheter was then carefully passed through the endocervical canal making sure it did not touch the vaginal wall Once it was confirmed that all embryos were transferred, the tip of the catheter Oast 1 cm) was cut off and placed in Stuart's transfer medium The catheter tips and dry endocervical swabs were separately transported in Stuart's transport medium All swabs and the transfer catheter Ups were each inoculated on five primary culture media within 2 h of collection. The media used included (l) 5% horse blood agar, (u) MacConkey's bile salt agar, (in) Sabouraud's glucose-peptone agar, (IV) 0 0075% neomycin blood agar, and (v) tomato juice agar (Oxoid) Plates were incubated for 48 h in aerobic, anaerobic and carbon 1687 by guest on July 22, 2011 humrep.oxfordjournals.org Downloaded from