Once a cesarean always a cesarean? A computer-assisted decision analysis

Objective A previous decision analysis models for two strategic choices for trial of labor or repeated cesarean after prior cesarean concluded that the degree of wish for an additional future pregnancy appeared to be a major determinant for choice between the two strategic options. We had extended the analysis model to stillbirth and hypoxic-ischemic encephalopathy in addition to placental complications while updating most of the outcomes in the decision tree. Study design A model was formulated using a decision tree based on reported probabilities for various outcomes and estimated utilities. The question asked was should trial of labor or repeated cesarean be performed after a prior cesarean, with a varying desire for an additional pregnancy. The highest expected outcome determines the preference of our model. Results Our model favors repeated elective cesarean (0.9947) over trial of labor (0.9917) after a previous cesarean and is the preferred approach. This approach was preferable irrespective of the probability of additional pregnancy. Conclusion In contrary to previous models, when taking into account the occurrence of a live infant birth, birth of an infant with hypoxic-ischemic encephalopathy stillbirth, neonatal death, abnormal placental implantation, hysterectomy and maternal death the preferred approach for women with previous cesarean is an elective repeated cesarean rather than trial of vaginal delivery.     

Validation of fetal cerebellar volume by three-dimensional ultrasonography in Brazilian population

BACKGROUND: To validate the prediction equation of the volume of fetal cerebellum by three-dimensional ultrasonography determined for Taiwan's population in Brazilian population. METHODS: A longitudinal prospective study was performed with 52 normal pregnant women between 20 and 32 weeks. The measurement of fetal cerebellar volume was done by virtual organ computer-aided analysis (VOCAL) method, with a rotation angle of 30 degrees. To establish the correlation of fetal cerebellar volume with gestational age, a polynomial regression analysis was performed, with cerebellar volume as dependent variable and gestational age as independent variable. To compare the prediction equation of the volume of fetal cerebellum in Taiwan's population and the equation established in this study, with the values obtained from Brazilian population (referential), we used the intraclass correlation coefficient, with the averages compared by paired Student's t test. RESULTS: The volume of fetal cerebellum was highly correlated with gestational age, and the best prediction equation obtained was of the second degree. The equation established in this study predicted cerebellar volumes more accurately than the equation established for Taiwan's population, since the average values of fetal cerebellar volume were more similar to the average values of reference. CONCLUSIONS: The equation established for Taiwan's population presented less accuracy in Brazilian population, possibly due to the strong ethnical differences between both populations.     

Quantitative PCR technique for the identification of microrearrangements of the AZFc region

Purpose: The AZFc region spans about 3.5 Mb and contains many amplicons causing recombination events. Several papers have reported the occurrence of AZFc partial deletions resulting from non allelic homologous recombination (NAHR) (“gr-gr”, “b1-b3” or “b2-b3” deletions), particularly in infertile patients. DAZ genes are present in 4 copies and rearrangements involve a modification of the number of DAZ genes. Methods: In addition to STS plus/minus PCR, we developed a quantitative technique using real time PCR (Q-PCR) to determine the number of DAZ genes. Fourteen DNA controls were selected to validate the use of Q-PCR to detect AZFc microrearrangements, and sperm DNA samples from 30 fertile men were studied. Results: Rearrangements of 14 controls were well identified with Q-PCR, and 2 AZFc partial deletions were detected in fertile men (1 “gr-gr” and 1 “b2-b3”). Conclusion: Q-PCR represents a well-adapted method to detect microrearrangements of the Y-chromosome, complementary to STS analysis.     

Legal and ethical issues in the international transaction of donor sperm and eggs

Pertinent ethical and legal issues in the international transaction of donor sperm and eggs are discussed. Firstly, there may be legislative and ethical “contradiction” by the local health authority in permitting import of donor gametes, due to varying policies on donor reimbursement in different countries. This is particularly significant in countries where the underlying principle of gamete donation is altruistic motivation, and where reimbursement is given only for direct “out-of-pocket” expenses i.e. traveling costs. Secondly, there is a lack of clear and coherent internationally-binding legislation and regulatory guidelines overseeing the exchange of donor gametes across international borders. In particular, provisions should be made for donor traceability if gametes are sourced from abroad. Thirdly, in the case of “frozen-egg donation” from abroad, patients must rightfully be informed that current cryopreservation technology is still sub-optimal, and all studies have consistently shown that the chances of conception are always lower with “frozen-eggs” compared to freshly-retrieved eggs. Finally, regulatory safeguards should be put in place to prevent fertility clinics and medical professionals from “re-selling” imported donor gametes at a profit to the patient, since it would be thoroughly unprofessional for them to earn a profit simply through the ‘brokerage’ of donated human material.     

Angiogenesis in implantation

Problem Implantation failure and early pregnancy loss are common following natural conceptions and they are particularly important clinical hurdles to overcome following assisted reproduction attempts. The importance of adequate vascular development and maintenance during implantation has recently become a major focus of investigation. Materials and methods Review of current published literature was undertaken to summerize the cells and cell products that regulate tissue vascularity during implantation. Results Vascular development at the maternal fetal interface can be regulated by a number of different cell types; two principal candidates are trophoblast and natural killer cells. A wide range of soluble factors, some with well established angiogenic functions as well as other more novel factors, can contribute to vascular development and maintenance at the maternal–fetal interface. Conclusions Robust vascular development occurs during implantation and early placentation of normal pregnancies. Studies to define the extent and mechanisms by which defects in vascularity contribute to human implantation failure and early miscarriage need to be undertaken. Vascular development during implantation is mediated by numerous cell types and cell products and aberrant vascularity likely contributes to implantation failure and early pregnancy loss.     

Cytokines: Important for implantation?

Problem

Cytokines are obviously very important in an established pregnancy, but what about human embryo implantation?

Methods

Literature review.

Results

We first discuss the necessity and limits of animal models, and then review the few cytokines which have been demonstrated by knock-out methods to be absolutely necessary for embryo implantation using in animal models. We then review what is known or discussed about the role of other cytokines as deduced from quantitative and/or qualitative dysregulation in animals and in humans.

Conclusions

Cytokines are indeed involved in implantation as they are in ongoing pregnancy and delivery. Relevance to infertility and recurrent pregnancy loss is discussed.     

Analysis of meiotic segregation patterns and interchromosomal effects in sperm from six males with Robertsonian translocations

Purpose To provide more genetic information about meiotic segregation behavior and the possibility of interchromosomal effects (ICE) in spermatozoa from carriers of Robertsonian (Rob) translocations. Materials and methods Meiotic segregation behavior in spermatozoa from six carriers of Rob translocations, four t(13;14), one t(14;22) and one t(13;21), was investigated by dual fluorescence in-situ hybridization (FISH). Aneuploidy for chromosomes 18, X and Y was studied by triple FISH. Results The rate of normal/balanced spermatozoa resulting from alternate segregation ranged from 78.14 to 86.88%. The frequency of unbalanced spermatozoa resulting from adjacent segregation varied between 11.70 and 19.53%. The higher frequencies of aneuploidy for sex chromosome were observed in three Rob translocation carriers. In addition, the increased rates of diploid were found in two t(13;14) carriers. Conclusions Alternate segregation is dominant in the different types of Rob translocations. Some carriers may be at an increased risk for ICE. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users. An increased aneuploidy for sex chromosome observed in three Robertsonian translocation carriers suggests that an interchromosomal effect is likely in some carriers.