PGD in 47,XXY Klinefelter's syndrome patients

The use of ICSI has been a major breakthrough in the treatment of male infertility. Even azoospermic patients with focal spermatogenesis in the testis, may benefit from the ICSI technique in order to father a child. As ICSI use has become more common, centres have introduced infertility treatment for Klinefelter patients. To date, 34 healthy children have been born using ICSI without PGD, and the conception of one 47,XXY fetus has been reported. In view of the possible risk of an increased gonosome number in the spermatozoa of Klinefelter patients, a safer approach--offering these couples ICSI combined with PGD--has been used, and has resulted in the birth of three healthy children. Couples in which the male suffered from Klinefelter's syndrome were first treated in 1995; these patients were offered ICSI + PGD using FISH technology, notably to enumerate the X and Y chromosomes. ICSI + PGD was performed in 32 cycles of 20 couples with spermatozoa originating from a fresh ejaculate (n = 1), testicular biopsy (n = 21) or frozen-thawed testicular biopsy (n = 10). Normal fertilization occurred in 56.0 +/- 22.4% of the successfully injected oocytes. On day 3 of development, 119 embryos from 29 cycles were of sufficient quality to undergo biopsy and subsequent PGD; a positive result was obtained in 113 embryos. Embryos were available for transfer in 26 cycles, with a mean of 1.6 +/- 0.6 embryos per transfer. Eight pregnancies were obtained, and five resulted in a delivery. A total of 113 embryos from couples with Klinefelter's syndrome was compared with 578 embryos from control couples with X-linked disease where PGD was used to determine gender. A significant fall occurred in the rate of normal embryos for couples with Klinefelter's syndrome (54.0%) compared with controls (77.2%). Moreover, a significantly increased risk of abnormalities was observed for sex chromosomes and autosomes; for each autosome separately, this reached significance level for chromosomes 18 and 21 only. Hence, a cautious approach is warranted in advising couples with non-mosaic Klinefelter's syndrome. Moreover, the use of ICSI + PGD or prenatal diagnosis should be carefully considered.     

Does PGD for aneuploidy screening change the selection of embryos derived from testicular sperm extraction in obstructive and non-obstructive azoospermic men?

BACKGROUND: An increased incidence of aneuploid embryos has been recently described from azoospermic men. The aim of this study was to assess if embryo selection on day 5, based on morphological criteria, would be different from the selection based on PGD for aneuploidy screening (AS) in couples undergoing ICSI for male azoospermia. METHODS: Sixty-two cycles of testicular sperm extraction (TESE)-ICSI with PGD-AS were included in the analysis. Two embryologists, blinded to the PGD-AS results, retrospectively reviewed the available embryology data from day 5 embryos and selected one, two or three embryos to be transferred. These results were compared with the selected embryos based on PGD-AS. RESULTS: A total of 39 cycles from non-obstructive azoospermia (NOA) and 23 cycles from obstructive azoospermia (OA) were retrospectively analysed. If single embryo transfer (SET) had been performed, in 64.8% of the NOA cycles and 54.5% of the OA cycles, no difference in embryo choice would have occurred compared to PGD-AS and in 10.8 and 36.6% of the cycles, respectively, an aneuploid embryo would have been chosen. If double ET (DET) had been performed, in 72.9% of the NOA cycles and 86.5% of the OA cycles, no difference in embryo choice would have occurred compared to PGD-AS and in 2.7 and 4.5% of the cycles, respectively, an aneuploid embryo would have been chosen. If triple ET (TET) had been performed, the outcome would have been the same as for DET. DISCUSSION: Our results suggest that under the terms of an SET policy, the performance of PGD-AS in azoospermia would result in a higher chance of success, as the possibility of selecting a euploid embryo is enhanced.     

Renal function in relation to three candidate genes in a Chinese population

We recently found in a white population that the genes encoding angiotensin-converting enzyme (ACE, I/D polymorphism), -adducin (Gly460Trp), and aldosterone synthase (–344C/T) jointly influence renal function. We therefore investigated in a Chinese population the associations between the serum concentrations of creatinine and uric acid and these three genetic polymorphisms. We genotyped 471 ethnic Han Chinese subjects from 125 nuclear families recruited in northern China via random population sampling (75%) and at specialized hypertension clinics (25%). We performed population-based and family-based association analyses using generalized estimating equations (GEE) and quantitative transmission disequilibrium test (QTDT), respectively, while controlling for covariables. The participants were 39.7 years old and included 235 women (49.9%). The blood pressure measured at the subjects homes averaged 126/80 mmHg. Mean values were 71 µmol/l for serum creatinine, 111 ml min^–1 1.73 m^–2 for calculated creatinine clearance, and 236 µmol/l for serum uric acid. With adjustment for covariables, GEE analyses of single genes demonstrated that serum uric acid, but not serum creatinine, was positively associated with the ACE D allele. Serum uric acid concentrations were 15.8 µmol/l (95% confidence interval 3.3–28.2) and 25.7 µmol/l (11.1–40.2) higher in DD homozygotes than in ID and II subjects, respectively. Further GEE analyses of the three genes combined showed that the association between serum uric acid and the ACE polymorphism was confined to carriers of the -adducin Gly and/or aldosterone synthase C alleles. Sensitivity analyses in parents and offspring separately as well as QTDT analyses were confirmatory. Among 114 informative offspring carrying the -adducin Gly allele serum uric acid was significantly and positively associated with the transmission of the ACE D allele (=20.7 µmol/l). In conclusion, the present study extends our previous findings on the combined effects of the three candidate genes and supports the concept that these genetic polymorphisms jointly influence renal function.     

PGD for a complex chromosomal rearrangement by array comparative genomic hybridization

Patients carrying a chromosomal rearrangement (CR) have an increased risk for chromosomally unbalanced conceptions. Preimplantation genetic diagnosis (PGD) may avoid the transfer of embryos carrying unbalanced rearrangements, therefore increasing the chance of pregnancy. Only 7-12 loci can be screened by fluorescence in situ hybridization whereas microarray technology can detect genome-wide imbalances at the single cell level. We performed PGD for a CR carrier with karyotype 46,XY,ins(3;2)(p23;q23q14.2),t(6;14)(p12.2;q13) using array comparative genomic hybridization. Selection of embryos for transfer was only based on copy number status of the chromosomes involved in both rearrangements. In two ICSI-PGD cycles, nine and seven embryos were analysed by array, leaving three and one embryo(s) suitable for transfer, respectively. The sensitivity and specificity of single cell arrays was 100 and 88.8%, respectively. In both cycles a single embryo was transferred, resulting in pregnancy following the second cycle. The embryo giving rise to the pregnancy was normal/balanced for the insertion and translocation but carried a trisomy 8 and nullisomy 9 in one of the two biopsied blastomeres. After 7 weeks of pregnancy the couple miscarried. Genetic analysis following hystero-embryoscopy showed a diploid (90%)/tetraploid (10%) mosaic chorion, while the gestational sac was empty. No chromosome 8 aneuploidy was detected in the chorion, while 8% of the cells carried a monosomy for chromosome 9. In summary, we demonstrate the feasibility and determine the accuracy of single cell array technology to test against transmission of the unbalanced meiotic products that can derive from CRs. Our findings also demonstrate that the genomic constitution of extra-embryonic tissue cannot necessarily be predicted from the copy number status of a single blastomere.     

The incidence of multiple pregnancy after in vitro fertilization and embryo transfer, gamete, or zygote intrafallopian transfer

This retrospective study concerns the incidence of multiple pregnancy after the replacement of three conceptus using different techniques of assisted reproduction. During a 2-year period, 713 in vitro fertilization-embryo transfers (IVF-ETs) with three embryos, 190 gamete intrafallopian transfers (GIFT) with three oocytes, and 161 zygote intrafallopian transfers (ZIFT) with three zygotes were performed. Although we observed significant differences in implantation and pregnancy rates (PRs), the three techniques resulted in high multiple PR. At 20 weeks, 16% of GIFT pregnancies, 27% of ZIFT pregnancies, and 32% of IVF-ET pregnancies were multiple. Therefore we recommend to limit the number of conceptus transferred to a maximum of three in all cases.     

The relationship between embryo quality and the occurrence of multiple pregnancies.

OBJECTIVE: To study the relationship between the quality of the transferred embryos and the occurrence of multiple pregnancies. Embryo quality was defined by the cleavage rate and by morphological parameters such as blastomere size and the presence or absence of anucleate fragments. DESIGN: A retrospective analysis of 1,915 consecutive transfers of fresh embryos between January 1986 and December 1989. SETTING: All the embryo transfers (ETs) were performed in patients from the in vitro fertilization program of the Center for Reproductive Medicine, Vrije Universiteit Brussel, Brussels, Belgium. RESULTS: We confirmed the relationship between the number of embryos transferred and the pregnancy rate (PR): 11.9% of the single, 19.0% of the double, and 34.1% of the triple ETs were successful. Thirty-one percent of these triple embryo replacements resulted in a multiple gestation. At the time of transfer (44 to 48 hours after insemination), we observed that embryos that had undergone at least two mitotic divisions implanted better than two-cell embryos of comparable morphological appearance (implantation rate per transferred embryo: 21.3% versus 12.3%, P less than 0.001) and that heavily fragmented embryos did not implant as well as embryos without or with fewer anucleate fragments (1.5% versus 14.1%, P less than 0.001). The PR, implantation rate, and the incidence of multiple pregnancies increased significantly with the number of good quality embryos that were transferred. CONCLUSIONS: Our study indicated that embryo quality based on morphological observations could predict the occurrence of multiple pregnancies.     

Benefits of antihypertensive pharmacologic therapy and blood pressure reduction in outcome trials

In a quantitative overview of published trials, we investigated whether pharmacologic properties of antihypertensive drugs, as opposed to reduction in blood pressure, explain cardiovascular outcomes in hypertensive or high-risk patients. We used meta-regression to investigate the association between the odds ratios of outcome (experimental vs. reference treatment) and the corresponding blood pressure differences between study groups. Thus, we correlated odds ratios with between-group differences in systolic pressure. We then compared odds ratios of benefit observed in recent trials with those predicted by meta-regression on the basis of the differences in systolic pressure between randomized groups. Among nine actively-controlled trials in hypertension, significant differences in systolic pressure (follow-up minus baseline) between randomized groups (experimental minus reference) were observed in the ALLHAT, CAPPP, MIDAS, and NORDIL trials. Furthermore, the differences in achieved systolic and/or diastolic pressure between study groups were also significant in the hypertension trials and studies in high-risk patients, which involved untreated control patients. The differences between the observed odds ratios and those predicted by meta-regression did not reach statistical significance except for NORDIL and the single-drug therapy subgroup of the PROGRESS trial. In NORDIL, the risk of stroke was lower on diltiazem than on the older drug classes despite a 3.1 mm Hg higher systolic pressure on the calcium channel blocker. In PROGRESS, perindopril alone reduced blood pressure by 5/3 mm Hg, but did not affect the incidence of all cardiovascular events or the recurrence of stroke. In conclusion, the finding that in the reviewed trials blood pressure reduction largely accounted for outcome emphasizes the desirability of tight blood pressure control. The hypothesis that blood pressure-lowering medications might influence cardiovascular prognosis over and beyond their antihypertensive effect remains to a large extent unproved.