ADministration of Clotrimazole prior to Frozen Embryo Transfer (FET) Cycles May Improve Implantation Rate

Abstract

Introduction We hypothesized 2 years ago that the presence of candidiasis whether clinical or sub- clinical may impact negatively on implantation and pregnancy rates. On this basis, we decided to put our patients prophylactically on clotrimazole (Canestan) one week prior to the embryo transfer. We found a trend to higher pregnancy and implantation rate in patients administered with Canestan as opposed to those who were not ( Lee et al., PGDIS, 2017 ). It is of interest that vaginal candidiasis has been associated with a reduced number of lactobacilli ( Hillier et al., 1992 ). Moreover, Moreno et al. (2016) also reported a significantly reduced implantation rate in IVF patients with a non-Lactobacillus- dominant endometrial microbiota. In this retrospective study, we review the effect of Canesten in the clinical outcome of FET patients. Material and Methods A total of 342 patients (age range=23-44) with blastocysts screened using Preimplantation Genetic Screening (PGS) underwent FET cycles in Alpha Fertility Centre, Malaysia, between July 2016 and October 2017. Oocyte donors were excluded from the study. These patients were divided into 2 groups: 290 patients with 362 euploid blastocysts transferred in the treatment group (Group A), and 52 patients with 64 euploid blastocysts transferred in the control group (Group B). All patients were administered with oestrogen (Progynova) and progesterone (Cyclogest or Crinone 8%) for endometrium preparation. In Group A, patients were given Canesten 500 mg pessary 7 days prior to embryo transfer. The mean age of patients in Group A was 34.3 while the mean age of patients in Group B was 35.3 (p>0.05). All thawed blastocysts survived with morphologically intact inner cell masses and trophectoderm cells. The mean number of blastocysts transferred was 1.2 each for Group A and B. Clinical pregnancy and number of gestational sacs were determined by ultrasound. Results The implantation rate was significantly higher in patients treated with Canesten (67.0%) compared to those who were not (53.1%) with a p value of 0.05). Conclusion Based on our preliminary result and this study with a larger sample size, it is suggestive that the use of Canesten pessaries in FET cycles is promising in improving implantation rate and this appears to apply to all age groups. Nevertheless, further studies which are controlled needs to be undertaken to confirm the above.