Elena Baroni

Embryo development of fresh ‘versus’ vitrified metaphase II oocytes after ICSI: a prospective randomized sibling-oocyte study

BACKGROUND A successful oocyte cryopreservation programme is of utmost importance where a limited number of oocytes can be inseminated per cycle, to overcome legal and ethical issues related to embryo storage, for oocyte donation programmes and for fertility preservation (especially for cancer patients). Vitrification has been recently proposed as an effective procedure for this purpose. METHODS In order to validate the effectiveness of oocyte vitrification a non-inferiority trial was started on sibling metaphase II (MII) oocytes. To demonstrate the non-inferiority based on an absolute difference of 17% in the fertilization rate per sibling oocyte, a minimum of 222 oocytes were required. After oocyte denudation, MII oocytes with normal morphology were randomly allocated to fresh ICSI insemination or to vitrification procedure. If pregnancy was not obtained a subsequent ICSI cycle was performed with warmed oocytes of the same cohort. In both groups, three oocytes were inseminated per cycle by ICSI procedure. Primary end-points were fertilization rates calculated per warmed and per injected oocytes. Secondary end-points were zygote and embryo morphology. RESULTS A total of 244 oocytes were involved in this study. Of the 120 fresh sibling oocytes inseminated, 100 were fertilized (83.3%). Survival rate of sibling vitrified oocytes was 96.8% (120/124 oocytes). Fertilization rate after ICSI was 76.6% (95/124) per warmed oocyte and 79.2% (95/120) per survived/inseminated oocyte. No statistical difference in fertilization rates was observed between the two groups when calculated per sibling oocytes (absolute difference −6.73%; OR: 0.65; 95% CI = 0.33–1.29; P = 0.20) and per inseminated oocyte (absolute difference −4.17%; OR: 0.76; 95% CI = 0.37–1.53; P = 0.50). Embryo development was also similar in both treatment groups up till Day 2. The percentage of excellent quality embryos was 52.0% (52/100) in the fresh group and 51.6% (49/95) in the vitrification group (absolute difference −0.43%; OR: 0.98; 95% CI = 0.53–1.79; P = 0.9). The mean age of the 40 patients included in this study was 35.5 ± 4.8 years (range 26–42). Fifteen clinical pregnancies were obtained in the vitrification cycles of 39 embryo transfers performed (37.5% per cycle, 38.5% per embryo transfer), with an implantation rate of 20.2% (19/94). Three spontaneous miscarriages occurred (20%). Twelve pregnancies are ongoing (30.0% per cycle, 30.8% per embryo transfer) beyond 12 weeks of gestation. CONCLUSIONS Our results indicate that oocyte vitrification procedure followed by ICSI is not inferior to fresh insemination procedure, with regard to fertilization and embryo developmental rates. Moreover, ongoing clinical pregnancy is compatible with this procedure, even with a restricted number of oocytes available for insemination. The promising clinical results obtained, in a population of infertile patients, need to be confirmed on a larger scale. Clinical Trials Registration number: iSRCTN60158641.

Cumulative ongoing pregnancy rate achieved with oocyte vitrification and cleavage stage transfer without embryo selection in a standard infertility program

BACKGROUND Recent advancement of minimum volume vitrification methods has resulted in a dramatic increase in the efficiency of the process. The aim of this study was to estimate the cumulative reproductive outcome of a cohort of infertile couples undergoing ICSI and oocyte vitrification in restrictive legal conditions, where only a limited number of oocytes could be inseminated per cycle and embryo selection and cryopreservation were forbidden. METHODS In this prospective longitudinal cohort study, the cumulative ongoing pregnancy rates obtained by the insemination of fresh and vitrified oocytes from the same cohort were calculated as primary outcome measures. Moreover, the effect of basal and cycle characteristics on clinical outcomes were assessed. RESULTS Between September 2008 and May 2009, 182 ICSI cycles were performed where oocyte vitrification was possible. A total of 104 first and 11 second oocyte warming cycles were then performed in non-pregnant patients of the same cohort. The overall ongoing pregnancy rates obtained in the fresh, and first and second warming cycles were 37.4, 25.0 and 27.3%, respectively. The overall cumulative ongoing clinical pregnancy rate observed per stimulation cycle was 53.3%. Maternal age was the only characteristic found to influence the reproductive outcome, with an inverse correlation between the age >40 and the ongoing pregnancy rates (P = 0.04, by Cox regression analysis). CONCLUSIONS High cumulative ongoing pregnancy rates can be obtained with transfers of embryos derived from fresh and cryopreserved oocytes in a typical infertile population. Female age significantly affects outcomes in this system.

Significance of metaphase II human oocyte morphology on ICSI outcome

OBJECTIVE To evaluate the influence of specific oocyte morphologic features (morphotypes) on intracytoplasmic sperm injection (ICSI) outcome. The identification of oocyte quality markers is particularly important when a low number of oocytes can be used for IVF. DESIGN Retrospective analysis. SETTING Medical center. PATIENT(S) Five hundred sixteen consecutive ICSI cycles. Only couples affected by severe male factor infertility were excluded. INTERVENTION(S) A total of 1,191 metaphase II (MII) oocytes (1-3 per patient) were randomly selected from the cohort of oocytes obtained from each patient and evaluated for morphologic appearance. MAIN OUTCOME MEASURE(S) Fertilization, pronuclear morphology, embryo quality, pregnancy rate. RESULT(S) There was a presence of vacuoles, abnormal I polar body, and large perivitelline space related to a lower fertilization rate. Pronuclear morphology was effected by the presence of a large perivitelline space, diffused cytoplasmic granularity, and/or centrally located granular area. The latter characteristic also negatively related to day 2 embryo quality. According to the odds ratios obtained for each oocyte morphotype to reach at least one outcome, an MII oocyte morphologic score (MOMS) was calculated. A significant relationship was found between MOMS and female age, female basal FSH, and clinical outcome. CONCLUSION(S) Morphologic evaluation before ICSI helps to identify MII oocytes with higher developmental potential.

Efficacy of double intrauterine insemination in controlled ovarian hyperstimulation cycles

OBJECTIVE To investigate the effectiveness of double IUI and to determine the optimal timing of IUI in relation to hCG administration. DESIGN Prospective randomized study. SETTING Infertility Center, Department of Obstetrics and Gynecology, University of Milan. PATIENT(S) Patients with male factor and unexplained infertility undergoing controlled ovarian hyperstimulation (COH) and IUI. INTERVENTION(S) After COH with clomiphene citrate and gonadotropins, patients were randomly assigned to one of the following groups: group A received a single IUI 34 hours after hCG administration, group B received a double IUI 12 hours and 34 hours after hCG administration, and group C received a double IUI 34 hours and 60 hours after hCG administration. MAIN OUTCOME MEASURE(S) Number of follicles > 15 mm in diameter on the day of hCG administration, number of motile spermatozoa inseminated, clinical pregnancy rate. RESULT(S) Two hundred seventy-three patients underwent 449 treatment cycles: 90 patients were treated for 156 cycles in group A, 92 patients for 144 cycles in group B, and 91 patients for 149 cycles in group C. The overall pregnancies rates for groups A, B, and C were 13 (14.4% per patient and 8.3% per cycle), 28 (30.4% per patient and 19.4% per cycle), and 10 (10.9% per patient and 6.7% per cycle), respectively. There was a statistically significant difference between group B and groups A and C. CONCLUSION(S) Our data indicate that two IUIs performed 12 hours and 34 hours after hCG administration is the most cost-effective regimen for women undergoing COH cycles with clomiphene citrate and gonadotropins. Although the second insemination adds up to a slightly higher cost, it significantly increases the chance of pregnancy.