No evidence that embryo selection by near-infrared spectroscopy in addition to morphology is able to improve live birth rates: results from an individual patient data meta-analysis.

STUDY QUESTION: What is the value of embryo selection by metabolomic profiling of culture medium with near-infrared (NIR) spectroscopy as an adjunct to morphology, compared with embryo selection by morphology alone, based on an individual patient data meta-analysis (IPD MA)? SUMMARY ANSWER: The IPD MA indicates that the live birth rate after embryo selection by NIR spectroscopy and morphology is not significantly different compared with the live birth rate after embryo selection by morphology alone. WHAT IS KNOWN ALREADY: Retrospective proof of principle studies has consistently shown that high NIR viability scores are correlated with a high implantation potential of embryos. However, randomized controlled trials (RCTs) have generally shown no benefit of the NIR technology over embryo morphology, although there have been some conflicting results between pregnancy outcomes on different days of embryo transfer. STUDY DESIGN, SIZE, DURATION: This IPD MA included all existing RCTs (n = 4) in which embryo selection by morphology was compared with embryo selection by morphology and the use of NIR spectroscopy of spent embryo culture medium by the Viametrics-E(™). PARTICIPANTS/MATERIALS, SETTING, METHODS: Searches of PubMed, the Cochrane Library and the WHO International Clinical Trials Registry were conducted and the sole manufacturer of the Viametrics-E(™) was consulted to identify clinics where an RCT comparing embryo selection by morphology to embryo selection by morphology and the use of the Viametrics-E(™) (NIR viability score) was performed. A total of 20 citations were potentially eligible for inclusion, two of which met the inclusion criteria. The manufacturer of the Viametrics-E(™) provided two additional clinical sites of use. In total, four RCTs were identified as eligible for inclusion. The IPD MA was based on a fixed effect model due to the lack of heterogeneity between included studies. Differences between study groups were tested and reported using logistic regression models adjusted for significant confounders. The pooled analysis of the primary outcome led to a total sample size of 924 patients: 484 patients in the control group (embryo selection by morphology alone) and 440 patients in the treatment group (embryo selection by morphology plus NIR spectroscopy). MAIN RESULTS AND THE ROLE OF CHANCE: The live birth rates in the control group and the NIR group were 34.7% (168 of 484) and 33.2% (146 of 440), respectively. The pooled odds ratio (OR) was 0.98 [95% confidence interval (CI) 0.74-1.29], indicating no difference in live birth rates between the two study groups. The data of the four studies showed no significant heterogeneity (I(2) = 26.2% P = 0.26). The multivariate regression analysis including all confounders show that maternal age (OR 0.90, 95% CI 0.87-0.94) and the number of previous IVF cycles (OR 0.83, 95% CI 0.71-0.96) were significantly related to live birth. The study group (i.e. embryo selection by morphology or embryo selection by morphology plus NIR) was not related to live birth (OR 0.97, 95% CI 0.73-1.29). LIMITATIONS AND REASONS FOR CAUTION: The availability of at least two similar best quality embryos as an inclusion criterion prior to transfer in the two largest RCTs might have caused a selection bias towards a better prognosis patient group. WIDER IMPLICATIONS OF THE FINDINGS: There is at present no evidence that NIR spectroscopy of spent embryo culture media in its current form can be used in daily practice to improve live birth rates.

Prediction of live birth in frozen-thawed single blastocyst transfer cycles by pre-freeze and post-thaw morphology.

STUDY QUESTION: What pre-freeze and post-thaw morphological parameters can be used to predict live birth outcomes after frozen-thawed blastocyst transfer cycles? SUMMARY ANSWER: Pre-freeze blastocoele expansion and trophectoderm (TE) grade and post-thaw degree of re-expansion are the most significant predictors of live birth in frozen-thawed blastocyst transfer cycles. WHAT IS KNOWN ALREADY: Currently, blastocoele re-expansion after thawing is used to indicate blastocyst cryosurvival and reproductive potential. The predictive roles of other pre-freeze and post-thaw morphological parameters are neglected. STUDY DESIGN, SIZE, DURATION: This was a retrospective study of all the patients who received a frozen-thawed single blastocyst transfer (n = 1089) at our clinic between March 2008 and October 2011. PARTICIPANTS/MATERIALS, SETTING, METHODS: Pre-freeze morphological parameters analyzed for all blastocysts included grade of blastocoele expansion, inner cell mass and TE. A group of blastocysts (n = 243) were also graded for post-thaw parameters: degree of blastocoele re-expansion, viability and cell contour. Univariate and multivariate generalized estimating equations (GEEs) models were used to identify the confounders that statistically significantly affected live birth outcomes and to investigate the independent effect of significant pre-freeze and post-thaw morphological parameters. Stepwise logistic regression analysis was used to select the best independent morphological predictors of live birth. Pearson correlations and linear regression analyses were performed to determine the relationship between morphological parameters and possible covariates. MAIN RESULTS AND THE ROLE OF CHANCE: Multivariate GEE models estimated that the odds of live birth increased by ∼36% for each grade of expansion (P = 0.0061) and decreased by 29% for blastocysts with grade B TE compared with grade A TE (P = 0.0099). Furthermore, the odds of live birth increased by ∼39% (P = 0.0042) for each 10% increase in degree of re-expansion. Blastocoele expansion and TE grade were selected as the most significant pre-freeze morphological predictors of live birth and degree of re-expansion was selected as the best post-thaw parameter for prediction of live birth. LIMITATIONS, REASONS FOR CAUTION: Blastocysts with poorer grades of morphology were not cryopreserved or transferred, limiting the ability to generalize our findings for grades of morphology not included in this study. WIDER IMPLICATIONS OF THE FINDINGS: Blastocysts with higher pre-freeze grades of expansion and TE, irrespective of day of cryopreservation, should be given priority when thawing. Subsequently, re-expanding blastocysts, assessed within 2-4 h, with >60% viability should be transferred. STUDY FUNDING/COMPETING INTEREST(S): No external funding was obtained for this study. There was no competing interest. TRIAL REGISTRATION NUMBER: not applicable.

Non-invasive metabolomic profiling of Day 2 and 5 embryo culture medium: a prospective randomized trial.

BACKGROUND: Near infrared (NIR) spectroscopy is a technology proposed to facilitate non-invasive screening for the most optimal human embryo for uterine transfer. It has been proposed that the NIR spectral profile of an embryo's spent culture medium can be used to generate a viability score that correlates to implantation potential. As the initial proof of principle studies were all retrospective, our aim was to investigate whether NIR spectroscopy on spent embryo culture medium in an on-site, prospective setting could improve the ongoing single embryo transfer (SET) pregnancy rate after Day 2 and 5 transfers. METHODS: We conducted a single-centre, double-blinded, randomized controlled trial in which the NIR group was compared with a control group. The primary outcome was the clinical pregnancy rate after 6-7 weeks of gestation per randomized patient. In the control group embryo selection was based only on traditional morphological evaluation while in the treatment group NIR spectroscopy was added to the morphological evaluation. RESULTS: The study was terminated early as the analysis of the Data Safety Monitoring Board showed a very low conditional power of superiority for the primary outcome. Of the 752 patients calculated to be included in the study, 164 and 163 patients were randomized into the NIR and control groups, respectively. No significant difference in the ongoing pregnancy rate per randomized patient was found between the NIR and the control group, 34.8 versus 35.6%, (P= 0.97). The proportional difference between the study groups mean was -0.8% (95% confidence interval -11.4 to 10.2). CONCLUSIONS: This study shows that adding NIR spectroscopy, in its present form, to embryo morphology does not improve the chance of a viable pregnancy when performing SET. The NIR technology appears to need further development before it can be used as an objective marker of embryo viability. CLINICAL TRIALS IDENTIFIER: ISRCTN23817363.

Trophectoderm morphology: an important parameter for predicting live birth after single blastocyst transfer.

BACKGROUND: In order to select the best blastocyst for transfer, in humans, three morphological parameters have routinely been used, i.e. degree of blastocoele expansion and appearance of both the trophectoderm (TE) and the inner cell mass (ICM). Although it has been shown that blastocysts with highest scores for all three parameters achieve highest implantation rates, their independent ability to predict pregnancy outcome remains unclear. METHOD: This study is a retrospective analysis of 1117 fresh day 5 single blastocyst transfers and their live birth outcome related to each morphological parameter. RESULTS: All three parameters had a significant effect on live birth however, once adjusted for known significant confounders, it was shown that TE was the only statistically significant independent predictor of live birth outcome. CONCLUSIONS: This study has shown, for the first time, the predictive strength of TE grade over ICM for selecting the best blastocyst for embryo replacement. It may be that, even though ICM is important, a strong TE layer is essential at this stage of embryo development, allowing successful hatching and implantation.

Obstetric outcomes after transfer of vitrified blastocysts.

BACKGROUND: It has been claimed that the risks to the child resulting from vitrification as compared with the slow-freezing technique, may be higher owing to the high concentrations of potentially toxic cryoprotectants. We therefore retrospectively compared the obstetric and neonatal outcomes in a cohort of children born after transfer of vitrified blastocysts, fresh blastocysts and slow-frozen early cleavage stage embryos. METHODS: All children born after transfer of vitrified blastocysts (n = 106), fresh blastocysts (n = 207) and slow-frozen early cleavage stage embryos (n = 206) during the period January 2006 to May 2008 at Fertility Center Scandinavia were included. Data on obstetric and neonatal outcomes were obtained from medical records from the antenatal and delivery clinics. RESULTS: For singletons, there were no significant differences between the groups in gestational age, mortality or birth defects. After adjustment for parity and BMI, birthweight was significantly higher in singletons born after transfer of vitrified blastocysts as compared with after transfer of fresh blastocysts (median 3560 versus 3510 g, P = 0.0311). More singletons born after transfer of fresh blastocysts were small for gestational age compared with singletons born after transfer of vitrified blastocysts (12.1 versus 3.0%, P = 0.0085). A higher rate of major post-partum haemorrhage was observed in the vitrified blastocyst group as compared with the other two groups (25.0 versus 6.0 and 7.5%). CONCLUSIONS: No adverse neonatal outcomes were observed in children born after transfer of vitrified, as compared with fresh blastocysts or after transfer of slow-frozen early cleavage stage embryos.

Re-analysis of 166 embryos not transferred after PGS with advanced reproductive maternal age as indication.

BACKGROUND: In a randomized controlled study aiming to test the effectiveness of preimplantation genetic screening (PGS) in women of advanced maternal age, embryos diagnosed as chromosomally abnormal and those with no diagnosis were fixed for reanalysis. The aim of this study was to determine how well the chromosomal constitution of one biopsied blastomere reflects the status of the entire embryo. METHODS: One hundred and seventy-three embryos diagnosed as chromosomally abnormal, 22 with no PGS result and four degenerated embryos originally diagnosed as normal were fixed and reanalysed by fluorescence in situ hybridization. RESULTS: In total, 199 embryos were fixed, of which 166 were successfully reanalysed. One hundred and sixty embryos were found to be chromosomally abnormal; 48 of the reanalysed embryos with an initial diagnosis (149) had at least one cell with exactly the same chromosomal constitution shown in the first PGS analysis (34.2%). The reanalysis confirmed the initial overall chromosomally abnormal status of the embryo in 95.9% of the cases. Of all chromosomally abnormal embryos, 4.1% were diagnosed as false positive. The risk for false negative rate was at least 4.1%. CONCLUSIONS: PGS seems to be a good method for selecting against chromosomally abnormal embryos but not for determining an embryo's exact chromosomal constitution.

Preimplantation genetic screening in women of advanced maternal age caused a decrease in clinical pregnancy rate: a randomized controlled trial.

BACKGROUND: Advanced maternal age (AMA) is an important parameter that negatively influences the clinical pregnancy rate in IVF, in particular owing to the increased embryo aneuploidy rate. It has thus been suggested that only transferring euploid embryos in this patient group would improve the pregnancy rate. The purpose of this study was to test whether employing preimplantation genetic screening (PGS) in AMA patients would increase the clinical pregnancy rate. METHODS: We conducted a two-center, randomized controlled trial (RCT) to analyze the outcome of embryo transfers in AMA patients (>or=38 years of age) after PGS using FISH analysis for chromosomes X, Y, 13, 16, 18, 21 and 22. The PGS group was compared with a control group. The primary outcome measure was clinical pregnancy rate after 6-7 weeks of gestation per randomized patient. RESULTS: The study was terminated early as an interim analysis showed a very low conditional power of superiority for the primary outcome. Of the 320 patients calculated to be included in the study, 56 and 53 patients were randomized into the PGS and control groups, respectively. The clinical pregnancy rate in the PGS group was 8.9% (95% CI, 2.9-19.6%) compared with 24.5% (95% CI, 13.8-38.3%) in the control group, giving a difference of 15.6% (95% CI, 1.8-29.4%, P = 0.039). CONCLUSIONS: Although the study was terminated early, this RCT study provides evidence against the use of PGS for AMA patients when performing IVF. TRIAL REGISTRATION NUMBER: ISRCTN38014610.

Increasing glucose levels and BMI predict future heart failure experience from the Reykjavík Study.

BACKGROUND: Heart failure is common in diabetes and ischaemic heart disease is the most likely link. Still, it has been suggested that the relation extends beyond such disease. METHODS: 7060 subjects with two or more visits in the Reykjavík Study were followed--during 30 years from 1967. All underwent oral glucose tolerance tests. Disease status was defined according to the glycaemic level and presence of heart failure. The incidence and predictive factors for these diseases were determined. FINDINGS: Age and sex standardized incidence of heart failure was 5.3/1000/year, of diabetes 4.6/1000/year and abnormal glucose regulation 12.6/1000/year. Body mass index (BMI) and fasting glucose predicted the development of these conditions (p<0.001). Increasing fasting glucose by 1 mmol/l increased the risk for heart failure by 14% (p=0.04) after adjusting for IHD, BMI and other risk factors for CVD. There was a strong association between diabetes and heart failure, OR 3.0 (2.3-4.0), and abnormal glucose regulation and heart failure, OR 1.8 (1.5-2.3). Diabetes and heart failure were, however, not independent predictors of each other. INTERPRETATION: There was an independent relationship between increases in fasting glucose and development of heart failure. BMI was a strong predictor of heart failure. Although fasting glucose and BMI were significant risk factors for glucose disturbances and heart failure the conditions themselves did not independently predict each other.

Avoidance of multiple pregnancy by use of single embryo transfer.

The benefits of single embryo transfer (SET) for both mother and child are evident. Already twin pregnancies constitute a relatively serious problem exemplified by the incidence of cerebral palsy, which will increase significantly as well as a risk for premature birth. Selective embryo reduction in countries where this is allowed may be one way to acutely solve the situation. In the beginning the use of natural cycle in vitro fertilization (IVF) avoided the problem, but with the introduction of controlled ovarian hyperstimulation predominantly by use of gonadotrophins in the early 1980ies the temptation to replace more than 1 embryo at a time became too strong. SET with maintenance of acceptable pregnancy rates can only be achieved if tools (improved morphological criteria, biomarkers, preimplantation genetic screening) to select the most viable/normal embryos are at hand together with improved cryopreservation procedures. In reports from Finland and Belgium already 5 years ago, elective single embryo transfer (eSET) was shown to reach almost the same success rates as double embryo transfer (DET) in selective patient groups (age under 37, good quality embryos). The indications for eSET have increased during the last years. In Finland the initiative came from the IVF clinics while in Sweden a legislative process (in act from January 2003) resulted in the recommendation that eSET should be used in the vast majority of the IVF cycles. In both these Nordic countries around 60% of the transfers are today eSET and the multiple pregnancy rate below 10% with no triplets. From an economical point of view, it is of course evident that multiple pregnancies with the numerous potential complications should be avoided altogether. Countries where IVF is included in the government health insurance will thus most likely show the way towards an even more successful, safer and cheaper treatment of infertile couples in the future.

Usefulness of preoperative and postoperative Tc-99m (Sn)-pyrophosphate scans in patients with ischemic and valvular heart disease.

To assess the usefulness of myocardial imaging with technetium-99m-stannous pyrophosphate for detecting acute myocardial necrosis in patients undergoind cardiac surgery, 66 such patients were stldied. Tc-99m (Sn)-pyrophosphate scans were obtained in all patients 3 to 6 days postoperatively and in 45 preoperatively. Electrocardiograms and serum samples for measuring myocardial isoenzyme of creatine kinase (MB CK) levels were obtained before and serially after cardiac surgery. Seven of the 46 patients undergoing myocardial revascularization had a definite new myocardial infarction as indicated by electrocardiogram and MB CK isoenzyme concentrations, and postoperative pyrophosphate scans were abnormal in all but one. In addition, six of the eight patients with possible myocardial infarction (elevated MB CK levels and persistent ST-T wave depressions) had an abnormal scan postoperatively. Seven of the 20 patients undergoing aortic or mitral valve replacement, or both, had a possible postoperative myocardial infarction by electrocardiogram and MB CK criteria and the myocardial scan was positive in two. All the patients with a normal electrocardiogram and normal MB CK levels had a normal pyrophosphate scan. Preoperative scans were obtained in 22 patients wit; valvular heart disease and were positive in two with a heavy calcified mitral valve on fluoroscopy and in one with a calcified aortic valve. After valve replacement, the pyrophosphate scan became normal in two patients and remained abnormal in the third patient with electrocardiograms and MB CK levels suggesting acute myocardial infarction. We conclude that the Tc-99m (Sn)-pyrophosphate scan is useful for analyzing the occurrence of acute myocardial infarction in patients undergoing cardiac surgery and that, in conjunction with the electrocardiogram, it permits confirmation or exclusion of that diagnosis. Furthermore, false positive pyrophosphate scans may occur in patients with heavy valve calcifications.

Importance of the lactate anion in control of breathing.

The purpose of this study was to examine the effects of raising the arterial La- and K+ levels on minute ventilation (VE) in rats. Either La- or KCl solutions were infused in anesthetized spontaneously breathing Wistar rats to raise the respective ion arterial concentration ([La-] and [K+]) gradually to levels similar to those observed during strenuous exercise. VE, blood pressure, and heart rate were recorded continuously, and arterial [La-], [K+], pH, and blood gases were repeatedly measured from blood samples. To prevent changes in pH during the La- infusions, a solution of sodium lactate and lactic acid was used. Raising [La-] to 13.2 +/- 0.6 (SE) mM induced a 47.0 +/- 4.0% increase in VE without any concomitant changes in either pH or PCO2. Raising [K+] to 7.8 +/- 0.11 mM resulted in a 20.3 +/- 5.28% increase in VE without changes in pH. Thus our results show that La- itself, apart from lactic acidosis, may be important in increasing VE during strenuous exercise, and we confirm earlier results regarding the role of arterial [K+] in the control of VE during exercise.

Biochemical screening of airmen.

Starting in 1983, biochemical and hematological screening, including hemoglobin, hematocrit, mean cell volume, mean red cell hemoglobin concentration, white blood cell count, ESR, serum creatinine, cholesterol, triglycerides, ASAT (SGOT), ALAT (SGPT), G-GT and blood glucose, was performed in all Icelandic captains, copilots, flight engineers, and air traffic controllers. No hematological abnormalities were observed. One pilot had serum creatinine above 150 mmol.L-1; 48 airmen had serum cholesterol above 8.9 mmol.L-1; 15 had blood glucose above 7.9 mmol.L-1. The pilots had significantly lower serum triglycerides, ALAT, and ASAT than the captains. Fifty airmen had G-GT values above 50 IU.L-1. This group was urged to reconsider their alcohol habits and given medical and psychological advice as indicated. In this group the mean G-GT fell from 89 to 37 IU.L-1 during a period of approximately 2 years. No change in G-GT values was observed in those airmen who had a normal initial value. This study demonstrates the value of routine biochemical testing for airmen, particularly as regards blood glucose, serum cholesterol, and G-GT.

Predictors of ongoing implantation in IVF in a good prognosis group of patients.

BACKGROUND: The aim of this study was to investigate whether, in a large randomized trial, it is possible to identify specific maternal and/or embryo variables that could independently correlate with ongoing implantation in IVF/ICSI. METHODS: In a Scandinavian study, 661 women were randomized to elective single embryo transfer or double embryo transfer. Women aged <36 years undergoing their first or second IVF cycle and with at least two good quality embryos were eligible. Only one cycle per subject was included. In the present study, cycles with 0 or 100% ongoing implantation (n = 520) were analysed regarding maternal and embryo variables. RESULTS: In this selected study group, the ongoing implantation rate was 195/734 (26.6%). In the univariate analysis, first IVF cycle, conventional IVF as fertilization method and 4-cell embryos showed a statistically higher ongoing implantation rate than did second IVF cycle, ICSI and non-4-cell embryos. In the multivariate analysis the same variables correlated independently to ongoing implantation. In addition, ovarian sensitivity correlated independently to ongoing implantation. CONCLUSION: This information should be used when selecting the number of embryos for transfer with the overall aim to reduce the rate of multiple births while maintaining a satisfactory birth rate.

The position of the metaphase II spindle cannot be predicted by the location of the first polar body in the human oocyte.

When performing intracytoplasmic sperm injection (ICSI) on human oocytes, the injection is traditionally made at the 3 o'clock position, with the first polar body (PB) at the 12 or 6 o'clock position. This has been based on the assumption that the second meiotic metaphase II (MII) spindle lies in close proximity to the first PB. The objective of this study was to document the actual spatial relationship between the first PB and the MII spindle both in in-vivo matured (fresh) human MII oocytes and in oocytes matured in vitro. We found that the MII spindle was, on average, not located directly adjacent to the PB. The in-vivo group (n = 54) showed a mean deviation of the MII spindle from the position of the PB of 41. 7 degrees and the in-vitro group 26.6 degrees (n = 43). The difference between the angle of the two groups was statistically significant (P = 0.005), indicating that the lateral displacement of the first PB is only partly due to the denuding procedure during ICSI, because the in-vitro matured oocytes were denuded before extrusion of the first PB. The majority of the MII spindles in both groups were found in the same hemisphere as the first PB, suggesting that care should be taken to avoid damaging the MII spindle by inserting the ICSI needle in the other half of the oocyte.

Effect of sublingual nitroglycerin on cardiac performance in patients with coronary artery disease and non-dyskinetic left ventricular contraction.

In 8 patients with coronary artery disease and symmetrical left ventricular contraction, an echocardiographic study of left ventricular function was performed before and 3 minutes after the administration of 0-6 mg nitroglycerin sublingually. The left ventricular end-diastolic diameter decreased from 5-2 +/- 0-2 to 4-9 +/- 0-2 cm (P less than 0-05) and the end-systolic diameter from 4-2 +/- 0-2 to 3-7 +/- 0-2 cm (P less than 0-001). The estimated stroke volume did not change significantly, while the cardiac output increased, 5-8 +/- 0-6 to 7-7 +/- 0-6 l min-1 (P less than 0-001) and the heart rate increased from 72 +/- 5 to 90 +/- 6 (P less than 0-001). The mean arterial blood pressure decreased from 105 +/- 4 to 88 +/- 3 mmHg (P less than 0-001). The ejection fraction increased from 53 +/- 3 per cent to 65 +/- 6 per cent (P less than 0-001) and the mean velocity of circumferential fibre shortening (VCF) from 0-81 +/- 0-05 to 1-15 +/- 0-10 circumferences per second (P less than 0-001). The estimated midsystolic midwall stress decreased from 155 +/- 14 g cm-2 to 102 +/- 12 g cm-2 after mitroglycerin (P less than 0-001). The administration of nitroglycerin was associated with a significant decrease in left ventricular preload and afterload. A vasodilating effect is suggested by the fall in peripheral resistance. The overall improvement in ejection fraction and VCF may not reflect a true increase contractility, because of the concomitant fall in wall stress.

Mode of inheritance of hypertrophic cardiomyopathy in Iceland. Echocardiographic study.

We used an abnormally thick interventricular septum (greater than or equal to 1.3 cm) as an echocardiographic marker to find the inheritance pattern of hypertrophic cardiomyopathy among relatives of eight patients who had that disease at necropsy. Forty normal subjects served as a control group. Fifty-eight family members were examined and 18 (41%) of the 44 first degree relatives had hypertrophic cardiomyopathy. The overall inheritance pattern was consistent with an autosomal dominant genetic disorder and in one family a recessive trait could be excluded. The diagnosis of hypertrophic cardiomyopathy can be difficult clinically as only 13% of our patients had serious symptoms and only 30% had abnormal auscultatory findings. The electrocardiogram is a useful screening test among relatives as it was abnormal in 20 (87%) of those who had an abnormally thick septum. Symmetric septal hypertrophy was found in 30% of patients with cardiomyopathy in this study and only 17% had clinical evidence of obstruction.