Comparison of effects of zona drilling by non-contact infrared laser or acid Tyrode's on the development of human biopsied embryos as revealed by blastomere viability, cytoskeletal analysis and molecular cytogenetics

Use of a non-contact infrared laser (IRL) or acid Tyrode's for zona drilling before embryo biopsy was compared by assessing blastomere viability using various fluorescent markers or culture of the single biopsied blastomere, and, by cytoskeletal and molecular cytogenetic analysis of the biopsied embryos following culture to the blastocyst stage. There was no significant difference in the proportion of biopsied embryos that showed no damage in both the biopsied blastomere and in the remaining embryo (acid Tyrode's: 75% versus IRL: 68%), or in the proportion of single biopsied blastomeres that divided in culture (P > 0.05). However, single biopsied blastomeres from laser drilled embryos showed a greater tendency to form miniblastocysts. The proportion of laser or acid Tyrode's biopsied embryos that reached the blastocyst stage by day 6 was similar, although evident earlier (day 5) in the laser biopsied embryos. Spindle abnormalities at the blastocyst stage included tripolar and tetrapolar spindles, but their incidence was not significantly different from controls. In addition, no significant difference was observed in the incidence of chromosomal abnormalities and mosaicism between the two groups. It is concluded that using an IRL at a safe working distance does not cause adverse immediate or longer term effects on the development of human biopsied embryos, although damage can occur if drilling within this distance is unavoidable. Acid Tyrode's drilling can also cause damage, and tended to retard blastocyst development.     

A new pattern for using both thoracic arteries to revascularize the entire heart: the π-graft

We present a complex graft for total arterial revascularization based on bilateral skeletonized internal thoracic arteries (ITA). The lower two-thirds of the free right ITA is anastomosed to the proximal segment of the left in situ ITA using the T-graft technique (Tector-Barner-Calafiore). The free, transected distal part of the left ITA is then anastomosed end-to-side on free right ITA (T-on-T anastomosis). In addition, the technique may use another graft extending the proximal third of the in situ right ITA with the free radial artery for right-sided revascularization. The entire operation can be performed off-pump to avoid any procedure on the ascending aorta.     

Cryptic sperm defects may be the cause for total fertilization failure in oocyte donor cycles

In conventional IVF cycles with total fertilization failure, rescue intracytoplasmic sperm injection (ICSI) performed 24h after insemination has yielded poor results. However, when ICSI is used, total fertilization failure is a rare event. The aim of the present study is to investigate the degree of sperm contribution to fertilization failures using the egg-sharing model in oocyte donor cycles. The study included only the oocyte donor cycles of sibling oocytes with total fertilization failure in at least one of the matched recipients. Oocytes from 49 oocyte donor cycles were equally shared among 98 recipients undergoing conventional IVF. Due to total fertilization failure in half of the recipients, rescue ICSI was carried out. Compared with the conventional IVF only group, the rescue ICSI group had a lower pregnancy rate (30.61% versus 71.43%), clinical pregnancy rate (28.57% versus 67.35%) and ongoing pregnancy rate (28.57% versus 63.27%) (all P<0.01). Cryptic sperm defects in apparently normal spermatozoa may be the cause of total fertilization failure, indicating the need for simple routine tests to detect them.     

Twin Pregnancy and Antenatal Examination: An Overview

Total twinning rate has increased dramatically during the past 20 years, especially in Europe and the United States. This increase is mainly attributed to the widespread implementation of assisted reproductive techniques (ART). Twin gestation presents hazards at all ranges of gestational period, including risk for fetal wastage, fetal growth restriction, preterm labor, congenital abnormalities, twin-to-twin transfusion syndrome (TTTS) regarding monochorionic twins, and increased mortality rates. This review presents a summary of the appropriate antenatal examination strategy in twin pregnancies and, in parallel, emphasizes the main clinical problems that still pose controversies. Detection of chorionicity, measurement of nuchal translucency, fetal growth assessment based on twin-adjusted customized charts, structural anomaly scan, invasive procedures, non-stress test, biophysic profile, and MRI performance are the main issues analyzed. Finally, because twin gestations represent a challenging reality of modern obstetrics, this review also elucidates on the domains characterized by lack of evidence-based consensus, therefore raising the need for further research.