Why and how should multiple pregnancies be prevented in assisted reproduction treatment programmes?

Predictive value of initial serum human chorionic gonadotropin levels for pregnancies after single fresh and frozen blastocyst transfer

As one of the earliest markers for predicting pregnancy outcomes, human chorionic gonadotropin (hCG) values have been inconclusive on reliability of the prediction after frozen and fresh embryo transfer (ET). In this retrospective study, patients with positive hCG (day 12 after transfer) were included to examine the hCG levels and their predictive value for pregnancy outcomes following 214 fresh and 1513 vitrified-warmed single-blastocyst transfer cycles. For patients who got clinical pregnancy, the mean initial hCG value was significantly higher after frozen cycles than fresh cycles, and the similar result was demonstrated for patients with live births (LB). The difference in hCG value existed even after adjusting for the potential covariates. The area under curves (AUC) and threshold values calculated by receiver operator characteristic curves were 0.944 and 213.05 mIU/mL for clinical pregnancy after fresh ET, 0.894 and 399.50 mIU/mL for clinical pregnancy after frozen ET, 0.812 and 222.86 mIU/mL for LB after fresh ET, and 0.808 and 410.80 mIU/mL for LB after frozen ET with acceptable sensitivity and specificity, respectively. In conclusion, single frozen blastocyst transfer leads to higher initial hCG values than single fresh blastocyst transfer, and the initial hCG level is a reliable predictive factor for predicting IVF outcomes.

Methods for endometrial preparation in frozen-thawed embryo transfer cycles

Frozen-thawed (FT) embryo transfer is a procedure used for the storage and transfer of excess embryos obtained during in vitro fertilization- intracytoplasmic sperm injection cycles. In recent years, improvements in laboratory conditions and limitations on the number of embryos to be transferred have led to a progressive increase in FT embryo transfer cycles. However, the best solution for endometrial preparation in these cycles is still a matter of debate. In this study, we aimed to review the current methods of endometrial preparation in FT embryo transfer cycles. In light of the current literature, it is hard to determine which method is the best for endometrial preparation. It is therefore necessary to conduct randomized controlled studies in a prospective design, which will also evaluate the above-mentioned factors.

Preimplantation mouse embryo selection guided by light-induced dielectrophoresis

Selection of optimal quality embryos for in vitro fertilization (IVF) transfer is critical to successful live birth outcomes. Currently, embryos are chosen based on subjective assessment of morphologic developmental maturity. A non-invasive means to quantitatively measure an embryo's developmental maturity would reduce the variability introduced by the current standard. We present a method that exploits the scaling electrical properties of pre-transfer embryos to quantitatively discern embryo developmental maturity using light-induced dielectrophoresis (DEP). We show that an embryo's DEP response is highly correlated with its developmental stage. Uniquely, this technique allows one to select, in sequence and under blinded conditions, the most developmentally mature embryos among a mixed cohort of morphologically indistinguishable embryos cultured in optimized and sub-optimal culture media. Following assay, embryos continue to develop normally in vitro. Light-induced dielectrophoresis provides a non-invasive, quantitative, and reproducible means to select embryos for applications including IVF transfer and embryonic stem cell harvest.

Global report on preterm birth and stillbirth (6 of 7): ethical considerations

INTRODUCTION

Despite the substantial global burden of preterm and stillbirth, little attention has been given to the ethical considerations related to research and interventions in the global context. Ethical dilemmas surrounding reproductive decisions and the care of preterm newborns impact the delivery of interventions, and are not well understood in low-resource settings. Issues such as how to address the moral and cultural attitudes surrounding stillbirths, have cross-cutting implications for global visibility of the disease burden. This analysis identifies ethical issues impacting definitions, discovery, development, and delivery of effective interventions to decrease the global burden of preterm birth and stillbirth.

METHODS

This review is based on a comprehensive literature review; an ethical analysis of other articles within this global report; and discussions with GAPPS's Scientific Advisory Council, team of international investigators, and a community of international experts on maternal, newborn, and child health and bioethics from the 2009 International Conference on Prematurity and Stillbirth. The literature review includes articles in PubMed, Academic Search Complete (EBSCO), and Philosopher's Index with a range of 1995-2008.

RESULTS

Advancements in discovery science relating to preterm birth and stillbirth require careful consideration in the design and use of repositories containing maternal specimens and data. Equally important is the need to improve clinical translation from basic science research to delivery of interventions, and to ensure global needs inform discovery science agenda-setting. Ethical issues in the development of interventions include a need to balance immediate versus long-term impacts--such as caring for preterm newborns rather than preventing preterm births. The delivery of interventions must address: women's health disparities as determinants of preterm birth and stillbirth; improving measurements of impact on equity in coverage; balancing maternal and newborn outcomes in choosing interventions; and understanding the personal and cross-cultural experiences of preterm birth and stillbirth among women, families and communities.

CONCLUSION

Efforts to improve visibility, funding, research and the successful delivery of interventions for preterm birth and stillbirth face a number of ethical concerns. Thoughtful input from those in health policy, bioethics and international research ethics helped shape an interdisciplinary global action agenda to prevent preterm birth and stillbirth.

Symposium: innovative techniques in human embryo viability assessment. Soluble human leukocyte antigen-G and pregnancy success

Non-invasive methods of assessing embryo quality are critical for pregnancy success following IVF or intracytoplasmic sperm injection (ICSI). The addition of new non-invasive morphological and biochemical analyses may further improve pregnancy success, allowing the transfer of a single embryo, thereby reducing the risks involved in multiple births following IVF/ICSI. The presence of a protein, soluble human leukocyte antigen-G (sHLA-G), in embryo cultures has been suggested as a way to non-invasively predict embryo quality and pregnancy success, especially when used in conjunction with current embryo quality assessment methods. Detection of sHLA-G in embryo culture medium has been correlated with pregnancy success in 12 studies, but three studies were not able to detect sHLA-G. This is a review of the literature on sHLA-G detection in IVF/ICSI, and reasons are proposed for the reported discrepancies, as well as guidelines for reporting of data in future studies. Furthermore, it is suggested that the use of an HLA-G transgenic mouse model would advance understanding of the mechanism of action of sHLA-G in preimplantation embryos and its correlation to embryo health and viability. Research on a mouse model, combined with clinical studies, should enable the development of a fast and reliable method for utilizing sHLA-G detection to improve pregnancy success after IVF/ICSI.

Phase-subtraction cell-counting method for live mouse embryos beyond the eight-cell stage

Since 1978 in vitro fertilization (IVF) procedures have resulted in the birth of over 3 million babies. Yet in 2005, IVF procedures had a live birth rate of only 34%, with 32% of these births resulting in multiple pregnancies. These multiple pregnancies were directly attributed to the transfer of multiple embryos to increase the probability that a single, healthy embryo was included. The predominantly accepted noninvasive viability markers for embryos created by IVF are (1) number of cells at specific time points during development and (2) overall morphology of the embryo. Currently, it is difficult to count the number of cells beyond the eight-cell stage noninvasively. We report a nontoxic cell-counting method capable of counting cell numbers ranging from 8 to 26 in live mouse embryos. This method is derived from the fusion of differential interference contrast and optical quadrature microscopy and is verified by epifluorescence images of Hoechst-stained nuclei. The phase-subtraction cell-counting method is the first accurate, nontoxic technique to count cells through the morula stage in mouse embryos and may enhance the use of cell number as a viability marker if adopted for use with human embryos in the IVF clinic.

Natural killer cell functional activity suppression by intravenous immunoglobulin, intralipid and soluble human leukocyte antigen-G

PROBLEM

The purpose of this study was to compare the ability of intravenous immunoglobulin (IVIg), intralipid and soluble human leukocyte antigen (sHLA)-G to suppress natural killer (NK) cell cytotoxicity in an in vitro assay.

METHOD OF STUDY

Blood samples taken from 275 women experiencing reproductive failure were analyzed for NK cytotoxicity and the suppression of NK cytotoxicity by IVIg 4 and 2 mg/mL (n = 275), intralipid 18 and 9 mg/mL (n = 275) and sHLA-G 70 and 35 ng/mL (n = 50) using immunofluorescent labeled K562 cells as targets and flow cytometry.

RESULTS

Natural killer cytotoxicity was suppressed in all samples. Among patients with normal NK cell activity, IVIg suppressed NK cytotoxicity by 44.9 +/- 8.1%, intralipid suppressed NK killing by 45.2 +/- 8.3% and sHLA-G suppressed by 49.0 +/- 9.2%. When specimens with abnormal NK activity were observed for suppression of cytotoxicity, IVIg suppressed by 38.9 +/- 5.4%, intralipid suppressed by 39.8 +/- 6.2% and sHLA-G suppressed by 39.9 +/- 5.0%.

CONCLUSION

Intravenous immunoglobulin, intralipid and sHLA-G suppressed NK cell cytotoxicity with equal efficacy in an in vitro assay.

Determination of the number of cells in preimplantation embryos by using noninvasive optical quadrature microscopy in conjunction with differential interference contrast microscopy

The number of cells in a preimplantation embryo is directly correlated to the health and viability of the embryo. There are currently no methods to count the number of cells in late-stage preimplantation embryos noninvasively. We assessed the ability of optical quadrature microscopy (OQM) to count the number of cells in mouse preimplantation embryos noninvasively. First, to test for possible light toxicity, we exposed two-cell mouse embryos to OQM and differential interference contrast (DIC) microscopy and assessed their ability to develop to the blastocyst stage. We found no inhibition of development from either mode of microscopy for up to 2 h of light exposure. We also imaged eight-cell to morula stage mouse preimplantation embryos by OQM nd developed two methods for counting the number of cells. The contour signature method (CSM) used OQM images alone and the phase subtraction method (PSM) used both OQM and DIC images. We compared both methods to standard cell counting techniques and found that the PSM was superior to all other noninvasive cell counting methods. Our work on mouse embryos should be applicable to human embryos. The ability to correctly count the number of cells in human preimplantation embryos could lead to the transfer of fewer embryos in in vitro fertilization (IVF) clinics and consequently a lower rate of high-risk multiple-infant births.

Ovarian stimulation length, number of follicles higher than 17 mm and estradiol on the day of human chorionic gonadotropin administration are risk factors for multiple pregnancy in intrauterine insemination

Aim:  The aim of the present study was to identify the risk factors, their prognostic value on multiple pregnancies (MP) prediction and their thresholds in women undergoing controlled ovarian hyperstimulation (COH) with follicle stimulating hormone (FSH) and intrauterine insemination (IUI). Methods:  A case-control study was carried out by identifying in our database all the pregnancies reached by donor and conjugal IUI (DIUI and CIUI, respectively), and compared cycle features, patients' characteristics and sperm analysis results between women achieving single pregnancy (SP) versus MP. The number of gestational sacs, follicular sizes and estradiol levels on the human chorionic gonadotropin (hCG) administration day, COH length and semen parameters were obtained from each cycle and compared. Student's t-tests for mean comparisons, receiver-operator curve (ROC) analysis to determine the predictive value of each parameter on MP achievement and multiple regression analysis to determine single parameter influence were carried out. Results:  Women with MP in IUI stimulated cycles reached the adequate size of the dominant follicle (17 mm) significantly earlier than those achieving SP. Also, the mean follicles number, and estradiol levels on the hCG day were higher in the CIUI and DIUI MP group. Nevertheless, only ROC curve analysis revealed good prognostic value for estradiol and follicles higher than 17 mm. Multiple regression analysis confirmed these results. No feature of the basic sperm analysis, either in the ejaculate or in the prepared sample, was different or predictive of MP. When using donor sperm, different thresholds of follicle number, stimulation length and estradiol in the prediction of MP were noted, in comparison with CIUI. Conclusions:  MP in stimulated IUI cycles are closely associated to stimulation length, number of developed follicles higher than 17 mm on the day of hCG administration and estradiol levels. Also, estradiol has a good predictive value over MP in IUI stimulated cycles. The establishment of clinical thresholds will certainly help in the management of these couples to avoid undesired multiple pregnancies by canceling cycles or converting them into in vitro fertilization procedures. (Reprod Med Biol 2007; 6: 19-26).

Improving the consistency of ovarian stimulation: follitropin alfa filled-by-mass

In their quest for a child, infertile couples embark on a journey that is full of expectations and hopes. Over recent years, treatment procedures for assisted conception have become safer and more efficient. However, couples undergoing treatment can still experience some degree of emotional stress due to disappointment if pregnancy is not achieved, or if treatment cycles may have to be cancelled due to a low- or hyper-response. Strategies aimed at minimizing the variability of ovarian response or overall treatment outcome can be expected to significantly reduce this emotional stress. New developments have led to the production of follitropin alfa filled by mass. This is a highly consistent FSH preparation improving the consistency of ovarian response and reducing the risk of cycle cancellation. The impact of this new FSH preparation for assisted reproduction treatments is discussed in this review.

Prevention of multiple pregnancy following IVF in Spain

Since the development of assisted reproduction techniques most countries have witnessed increased rates of multiple pregnancy. Despite the guidelines proposed by various scientific societies these rates continue to be abnormally high. In Spain, as in other Mediterranean countries, a greater number of embryos are transferred than in northern and central European countries and the incidence of multiple pregnancies is greater in comparison. Effective strategies must be established to prevent multiple pregnancy without reducing overall pregnancy rates. In the authors' institute, taking into account the authors' experience, the relevant literature, and despite the limitation of retrospective studies, it is recommended that a maximum of two embryos are transferred in young women with good quality embryos at the time of transfer. The transfer of three embryos is only recommended in women >or=38 years who have one or no good quality embryos available at the time of transfer. The responsibility for preventing multiple pregnancy lies with health professionals, who must be aware of the risks involved in twin and triplet pregnancy. Couples must be provided with objective information before starting an IVF cycle. Professional societies should highlight the problem and make suitable recommendations.

Factors predicting IVF treatment outcome: a multivariate analysis of 5310 cycles

The objective of this study was to analyse factors predicting live birth rate following IVF. A computerized database of 1928 women who underwent 5310 consecutive IVF cycles in a single IVF unit was evaluated. Data on the women's age, number of retrieved oocytes, performance of intracytoplasmic sperm injection (ICSI), aetiology of infertility, number of transferred embryos and option of choosing embryos for transfer were evaluated. There were 1126 pregnancies that resulted in 689 live births. Transferring two embryos doubled the chances of delivery compared with one embryo, but transferring three embryos was not significantly superior to two embryos. Moreover, following a three-embryo transfer, the multiple delivery rates were significantly higher (P < 0.01) compared with transferring two embryos. Optimal delivery rates were observed in women aged 26-30 years, with gradual decline with advanced age. The performance of ICSI resulted in higher delivery rates compared with conventional insemination. According to these data, the best live birth results following IVF treatment were achieved when the maternal age was 26-30 years, in couples with male factor infertility undergoing ICSI, and when two embryos were transferred.

Outcome of assisted reproductive technologies after different embryo transfer strategies

The outcomes of 1028 assisted reproductive technology cycles were studied retrospectively, considering two different periods of embryo transfer. In the first period, 262 cycles in women < 36 years old were studied, in which three embryos were transferred, followed by 157 cycles in women > or = 36 years, in which four embryos were transferred. In the second period, 332 cycles were evaluated in women < 36 years and 277 cycles in women > or = 36 years old, reducing the number of embryos transferred to two and three respectively. Embryos were only scored morphologically, and the best embryos were chosen for transfer. In the first period, in women < 36 years old, a clinical pregnancy rate of 55.7% was achieved, compared with 42.5% in the second period (P < 0.01). In women > or = 36 years old, the first period of embryo transfer showed a clinical pregnancy rate of 39.5%, compared with 28.5% in the second period (P < 0.01). The number of twin pregnancies in the three groups of patients in whom one to four embryos were transferred was not significantly different (24.2, 28.4, 24.8%). It is concluded that even with the biases induced by a retrospective study, the reduction in the number of embryos transferred, from three to two in women < 36 years of age, and from four to three in women > or = 36 years of age, without any selection other than pre-transfer morphological score, adversely affects the outcome of treatment, without a significant reduction in twin gestation rate. Other strategies are to be implemented in gametes and embryo selection, and patients must be aware that, even with a reduction in pregnancy rate, the goal is to achieve a high cumulative pregnancy rate, reducing the complications induced by multiple pregnancies.

Obstetric and perinatal outcome of 1655 ICSI and 3974 IVF singleton and 1102 ICSI and 2901 IVF twin births: a comparative analysis

A total of 3974 IVF and 1655 ICSI singleton births and 2901 IVF and 1102 ICSI twin births were evaluated. Pregnancies after both fresh and frozen transfers were included. IVF and ICSI singleton pregnancies were very similar for most obstetric and perinatal variables. The only significant difference was a higher risk for prematurity (< 37 weeks of amenorrhoea) in IVF pregnancies compared with ICSI pregnancies (12.4 versus 9.2%, OR = 1.39, 95% CI = 1.15-1.70). For twin pregnancies, differences were not statistically different except for a higher incidence of stillbirths in the ICSI group (2.08 versus 1.03%, OR = 2.04, 95% CI = 1.14-3.64). Intrauterine growth retardation with or without pregnancy-induced hypertension was observed more often in the ICSI group. Regression analysis of the data with correction for parity and female age showed similar results for twins. For singletons, this analysis showed similar results with the exception of low birth weight babies (< 2500 g), which were also observed more often in IVF pregnancies (9.6 versus 7.9%, OR = 0.79, CI = 0.65-0.98, P = 0.03). This large case-comparative retrospective analysis showed that the obstetric outcome and perinatal health of IVF and ICSI pregnancies is comparable.