Single or double embryo transfer? Decision-making process in patients participating in an oocyte donation program.

In IVF/ICSI programs, after receiving the information about the success results of single embryo transfer (SET) vs double embryo transfer (DET) and the risks of multiple pregnancy, a significant number of patients opt for SET. Up to date, no comparable studies have been published in oocyte recipients. The aim of this study was to evaluate if the counseling provided to oocyte recipients influence their decision on the number of embryos to be transferred. Fifty-five recipients expressed their preference and the relevance for the decision-making process that they attribute to certain factors through an anonymous questionnaire completed pre and post-counseling. Before counseling, 32 out of 55 recipients preferred DET, 13 preferred SET and 10 were undecided. From the 32 recipients who preferred DET, 16 (50%) maintained their preference after counseling, 13 (40.6%) changed their decision to SET and 3 (9.4%) changed to undecided (McNemar's test: p < .05). After counseling, the patients attached less importance to the probability of pregnancy and more importance to maternal and perinatal risks (p < .05). We conclude that after counseling, a significant number of recipients changed their preferences from DET to SET.

Clinical success of IUI cycles with donor sperm is not affected by total inseminated volume: a RCT.

STUDY QUESTION: What is the impact on live birth rates (LBR) when a donor IUI (dIUI) cycle is performed with an insemination volume of 0.5 mL versus the usual 0.2 mL? SUMMARY ANSWER: LBR after a dIUI cycle is no different when performed with 0.5 versus 0.2 mL. WHAT IS ALREADY KNOWN: An IUI has an important role in the treatment of severe male infertility, and is often used in same-sex female couples and single parents. Different variables have been studied to determine factors correlated with clinical outcomes (IUI scheduling, ovarian stimulation, sperm parameters) but little is known about the inseminated volume. The use of conical bottom test tubes could contribute substantially to the loss of inseminated spermatozoa because it precludes the total recovery of the sample. Additionally, the insemination catheter could uphold this reduction causing sperm adhesion on the inner walls of the insemination catheter, decreasing even more the total inseminated volume. It is expected that utilizing an IUI approach that increases sperm volume in the fallopian tubes (0.5 mL rather than 0.2 mL) at the time of ovulation will lead to higher LBRs. To avoid bias related to sperm quality, the study population was restricted to dIUI cycles. STUDY DESIGN SIZE AND DURATION: A parallel-group, double-blinded, RCT, including patients undergoing natural or stimulated dIUI, was performed between March 2013 and April 2015. dIUI cycles (n = 293) were randomized through a computer-generated list to undergo insemination with 0.2 mL (control group) or 0.5 mL (study group), of which 24 were excluded (protocol deviation) and 269 received the allocated intervention. Patients with the presence of tubal factor infertility, grades III-IV endometriosis, >3 previous dIUI cycles or with ≥3 follicles >14 mm were excluded. The study was designed with 80% power to detect a 5% difference in LBR with a reference of 15% and a two-tailed 5% significance level. The required sample size was 118 per group. PARTICIPANTS/MATERIALS SETTING AND METHOD: There were 143 cycles (0.2 mL group) and 126 cycles (0.5 mL group). The primary end-point of the trial was LBR per dIUI cycle in both treatment groups. Clinical pregnancy rate and miscarriage rate were evaluated as secondary outcomes. MAIN RESULTS AND THE ROLE OF CHANCE: No adverse events were reported during the study trial. Study groups (0.2 versus 0.5 mL, respectively) were similar in age (35.8 ± 3.9 versus 35.4 ± 4.0 years: mean±SD), and had similar anti-Mullerian hormone levels (2.2 ± 1.8 versus 2.0 ± 1.5 ng/mL), basal antral follicle count (13.2 ± 6.4 versus 13.6 ± 6.0), BMI (23.5 ± 3.9 versus 23.7 ± 4.1 kg/m2), number of follicles >17 mm (1.1 ± 0.5 versus 1.1 ± 0.5), total gonadotrophin dose (553.1 ± 366.3 versus 494.6 ± 237.1 IU), and total motile sperm count (8.22 ± 7.1 versus 7.7 ± 5.7 million). Similar clinical pregnancy rates (18.9% (27/143) versus 19.8% (25/126), NS), LBRs (15.4% (22/143) versus 19.0% (24/126), NS) and miscarriage rates (18.5% (5/27) versus 4.0% (1/25), NS) were observed between groups. LIMITATIONS REASONS FOR CAUTION: The study was not powered to detect differences in the secondary outcomes, clinical pregnancy and miscarriage rates. The randomization was performed at the dIUI cycle level, therefore, the results are reported as success rate per dIUI cycle rather than per patient. WIDER IMPLICATIONS OF THE FINDINGS: This is the first RCT to show that the inseminated volume is not correlated with the probability of a live birth. The miscarriage rate was higher in the 0.2 mL group, although this difference was not statistically significant. If the lower miscarriage rate observed in the 0.5 mL group is confirmed, this could be related to the presence of uterine contractions similar of those generated during sexual intercourse, which may be implicated in the inception of early biochemical embryo-endometrium communication. STUDY FUNDING/COMPETING INTERESTS: All authors declare having no conflict of interest with regard to this trial. No funding was received for this study. This research was performed under the auspices of 'Càtedra d'Investigació en Obstetrícia I Ginecologia' of the Department of Obstetrics, Gynaecology and Reproductive Medicine, Hospital Universitari Quiron-Dexeus, Universitat Autònoma de Barcelona. TRIAL REGISTRATION NUMBER: The trial was registered at clinicaltrials.gov (Identifier: NCT03006523).

Replacing GnRH agonists with GnRH antagonists in oocyte recipient cycle did not adversely affect the pregnancy rates.

UNLABELLED: The synchronization of the donor stimulation with the endometrial preparation of the recipient is usually done by downregulating the recipient's pituitary with a GnRH analog. OBJECTIVE: The aim of this study is to compare pregnancy and implantation rates among premenopausal oocyte recipients synchronized by pituitary suppression with GnRH agonist (Group AGO) or antagonist (Group ANTAG) and standard endometrial preparation with estrogen and gestagen. STUDY DESIGN: Prospective, observational, transversal, comparative study. Consecutive recipients treated at Institut Universitari Dexeus between July 2008 and December 2009. RESULTS: One hundred and eighty-three premenopausal women were included. No differences were found regarding the age of donors nor the age of recipients, fertilization rates, number of embryos transferred and embryo quality. No differences were found in clinical pregnancy rates (56.1% Group AGO vs. 52.4% Group ANTAG). CONCLUSION: The administration of GnRH antagonists during endometrial preparation in oocyte recipients facilitates synchronization without affecting the pregnancy rate.

Telomere dysfunction: a new player in radiation sensitivity.

Human individuals often exhibit important differences in their sensitivity to ionising radiation. Extensive literature links radiation sensitivity with impaired DNA repair which is due to a lack of correct functioning in many proteins involved in DNA-repair pathways and/or in DNA-damage checkpoint responses. Given that ionising radiation is an important and widespread diagnostic and therapeutic tool, it is important to investigate further those factors and mechanisms that underlie individual radiosensitivity. Recently, evidence is accumulating that telomere function may well be involved in cellular and organism responses to ionising radiation, broadening still further the currently complex and challenging scenario.

Postreplicative joining of DNA double-strand breaks causes genomic instability in DNA-PKcs-deficient mouse embryonic fibroblasts.

Combined cytogenetic and biochemical approaches were used to investigate the contributions of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) in the maintenance of genomic stability in nonirradiated and irradiated primary mouse embryo fibroblasts (MEF). We show that telomere dysfunction contributes only marginally to genomic instability associated with DNA-PKcs deficiency in the absence of radiation. Following exposure to ionizing radiation, DNA-PKcs-/- MEFs are radiosensitized mainly as a result of the associated DNA double-strand break (DSB) repair defect. This defect manifests as an increase in the fraction of DSB rejoining with slow kinetics although nearly complete rejoining is achieved within 48 hours. Fifty-four hours after ionizing radiation, DNA-PKcs-/- cells present with a high number of simple and complex chromosome rearrangements as well as with unrepaired chromosome breaks. Overall, induction of chromosome aberrations is 6-fold higher in DNA-PKcs-/- MEFs than in their wild-type counterparts. Spectral karyotyping-fluorescence in situ hybridization technology distinguishes between rearrangements formed by prereplicative and postreplicative DSB rejoining and identifies sister chromatid fusion as a significant source of genomic instability and radiation sensitivity in DNA-PKcs-/- MEFs. Because DNA-PKcs-/- MEFs show a strong G1 checkpoint response after ionizing radiation, we propose that the delayed rejoining of DNA DSBs in DNA-PKcs-/- MEFs prolongs the mean life of broken chromosome ends and increases the probability of incorrect joining. The preponderance of sister chromatid fusion as a product of incorrect joining points to a possible defect in S-phase arrest and emphasizes proximity in these misrepair events.

Capping of radiation-induced DNA breaks in mouse early embryos.

The aim of the study was to investigate the spectrum and frequencies of chromosome aberrations induced by the exposure of different mouse spermatogenic germ cell stages to ionizing radiation. Male mice were exposed in vivo to X-rays. Chromosome aberrations were analyzed in first- and second-embryonic cleavages obtained from mating irradiated males with nonirradiated females at different periods after radiation exposure. A combination of telomeric and centromeric labeling as well as whole Y chromosome painting was used to characterize the rejoining pattern and the telomere status of the radiation-induced DNA breaks. The frequency of chromosome aberrations observed in eggs fertilized with sperm irradiated at the early spermatid stage was markedly higher than the frequency in eggs fertilized with sperm irradiated at the other spermatogenic stages when reference was made to the chromosome aberrations recovered in early embryos. At the first division postirradiation, distal rejoining of broken chromosome ends (in regard to the position of the centromere) was more frequent than proximal rejoining; thus compound acentric fragments were more frequently observed than dicentric chromosomes. The presence of additional telomere signals at the broken chromosome ends in mouse germ cells and early embryos, compatible with de novo formation of telomeres, was not frequent.

Repair of DNA broken ends is similar in embryonic fibroblasts with and without telomerase.

Telomeres cap the ends of chromosomes, preventing end-to-end fusions and subsequent chromosome instability. Here we used a telomerase knockout model to investigate whether telomerase participates in the processes of DNA break repair by de novo synthesis of telomere repeats at broken chromosome ends (chromosome healing). Chromosome healing giving rise to new detectable telomeric signals has not been observed in embryonic fibroblasts of telomerase-proficient mice exposed to ionizing radiation. Since the synthesis of telomeric sequences to broken DNA ends would make them refractory to rejoining events, the efficiency of rejoining of broken chromosomes in cell environments with and without telomerase has also been investigated. We conclude that the efficiency of rejoining broken chromosomes is not significantly different in the two cell environments. All together, our results indicate that there is no significant involvement of telomerase in the healing of broken DNA ends by synthesizing new telomeres in mouse embryo fibroblasts after exposure to ionizing radiation.

Shortened telomeres join to DNA breaks interfering with their correct repair.

Telomeres cap chromosome ends, avoiding end-to-end fusions and subsequent chromosome instability. Telomeric functions and DNA repair pathways are closely related. Telomere dysfunction has been shown to result in hypersensitivity to ionizing radiation. In this study, we have used the telomerase knockout model to investigate how telomere shortening influences the correct repair of broken chromosomes. We show that the correct repair of double-strand breaks is impaired in telomerase knockout mice. The chromosomes with shortened telomeres fuse to radiation-induced breaks, interfering with the correct rejoining of the broken ends. This type of fusion is responsible for the increased chromosome instability observed in this mouse model, after exposure to ionizing radiation. Our finding may be important for understanding the increased radiation sensitivity associated with age in humans, as well as for comprehending the interindividual differences to the cytotoxic effects of radiation therapy in cancer patients.