INTRODUCTION

1. ASSISTED HATCHING AND NATURAL CYCLE: A RETROSPECTIVE STUDYPappa H., Liarmakopoulou S., Argyriou A., Sarella A., Xydias G.Diagnosis-IVF Department, 166 Alexandras Av., Athens, Greece INTRODUCTION The first successful birth after in vitro fertilization (IVF) was achieved in a natural unstimulated cycle. Since then, pregnancy rates have improved with the use of ovulation induction techniques, mainly as a result of transferring several embryos. However, certain disadvantages such as ovarian hyperstimulation, multiple pregnancies, premature birth, expensive and risky stimulating protocols are often involved in IVF cycles. Natural cycles have been proposed as an alternative to simplify IVF treatment procedures and reduce their costs and complications. Furthermore, several procedures such as assisted hatching have been involved in order to optimize implantation rates and thus, pregnancy rates in natural cycles. Our objective was to assess the efficacy of assisted hatching (AH) in women with poor ovarian response enrolled in a natural cycle. MATERIALS AND METHODS Patients were divided into two groups, group I, where assisted hatching was performed in the embryos and group II, where assisted hatching was not performed. Both groups were monitored daily or every two days ultrasound follicular measurements and whenever a follicle diameter 15±1mm was scanned, daily assessment of E2 and LH levels occurred. When LH measurement was 7-12 IU/l and the follicle diameter 17mm, 6500 IU of hCG were administered the same evening and oocyte retrieval was performed 35 hours later. ICSI was performed in all cases. A quarter partial assisted hatching was performed using a Laser (Saturn-RI) for the drilling. A chi-square test was used to compare clinical pregnancy between the groups. Figure 1: Laser Assisted Hatching. RESULTS 56 single embryo transfers were performed, 32 with AH (group I) and 24 without AH (group II). Mean age of women at treatment was comparative (36,94 ±4,812 and 37,04±4,298 for groups I and II respectively). The percentage of high quality embryos transferred was 71,9% in group I and 50% in group II. The clinical pregnancy rate per transfer was 25% in group I and 33.3% in group II. Figure 2: % Pregnancies resulted from the two groups of embryos with & without assisted hatching. CONCLUSIONS Many studies have been published concerning the beneficial role of assisted hatching in IVF. Most of them suggest that the use of a laser may be better than the chemical way (acide tyrodes). However, data from the present study show that assisted hatching may not be beneficial in natural cycles in poor responder women. On the contrary, we observed a better pregnancy rate in the group where we did not perform assisted hatching. Chi-square analysis failed to show a statistically significant difference between our results, thus, we suggest that more cases should be done in order to obtain a safer conclusion.