Ronit Machtinger

Objective Opposite sex twins have shown behavioral and reproductive differences between females and males. These differences may be determined by higher intrauterine levels of androgens among females that were exposed to a male co‐twin. The aim of this study was to compare cord blood androgen levels in females from same and opposite sex twins. Design A prospective study. In this pilot study we compared cord blood androgens (DHEA‐S, Δ‐4 Androstenedione, total testosterone ‐ TT) and sex hormone‐binding globulin (SHBG) levels in 20 females from same sex and 20 females from opposite sex dichorionic diamniotic twins. We used generalized estimating equation (GEE) modeling to assess differences in cord blood androgens between females from same‐sex twin pregnancies and females from opposite‐sex twin pregnancies. Patients Twenty opposite‐sex twin pairs (female‐male twins) and 20 same‐sex twin pairs (female‐female). Measurements Cord blood total Testosterone, Δ‐4 Androstenedione, DHEA‐S and Sex hormone‐binding globulin (SHBG) levels Results No difference in the levels of androgens as Δ‐4 Androstenedione, total testosterone and SHBG were identified between females that were exposed to a female co‐twin compared with females that were exposed to a male co‐twin. DHEA‐S levels were significantly lower among females from opposite‐sex twins compared with females from same sex twins. Conclusions Our preliminary data do not support the hypothesis that females exposed to male co‐twins are exposed to higher levels of androgens in utero compared with females exposed to female co‐twins. Further studies are needed to explain the reported behavioral and reproductive differences among opposite‐sex twins.

Partial thawing of a vial of cryopreserved sperm (shaving) is sometimes applied as a measure to preserve sperm for further use, particularly in cases of very restricted sperm quantity. However, mechanical violence may disrupt the sperm-wall and lead to impaired in-vitro fertilization (IVF) outcomes. In a retrospective case-control study at a tertiary, university-affiliated medical center, we compared the IVF/intracytoplasmic sperm injection (ICSI) outcomes of patients who used donor sperm following partial thawing (shaving) of the vial of cryopreserved sperm (n = 99) to a control group consisting of patients for whom the vial of sperm was completely thawed before use (n = 99). While no differences were observed in the rates of oocyte fertilization, the mean number of top-quality embryos (TQE) was significantly lower in the shaving group than in the complete thawing group (1.33 +/- 0.17 vs. 1.87 +/- 0.17, p < 0.02). Experimental analysis of aliquots from the same donors revealed significantly reduced motility in sperm samples that were shaved vs. fully thawed (6.5 vs. 37.1%, p < 0.001). In cases in which available cryopreserved sperm samples are limited, shaving of the vial without thawing can be used but with caution and only when absolutely necessary. Further, large prospective studies are needed to better clarify whether there is post-thawing sperm damage and to compare IVF outcomes after these two thawing methods.

A multidisciplinary group of experts gathered in Parma Italy for a workshop hosted by the University of Parma, May 16–18, 2014 to address concerns about the potential relationship between environmental metabolic disrupting chemicals, obesity and related metabolic disorders. The objectives of the workshop were to: 1. Review findings related to the role of environmental chemicals, referred to as “metabolic disruptors”, in obesity and metabolic syndrome with special attention to recent discoveries from animal model and epidemiology studies; 2. Identify conclusions that could be drawn with confidence from existing animal and human data; 3. Develop predictions based on current data; and 4. Identify critical knowledge gaps and areas of uncertainty. The consensus statements are intended to aid in expanding understanding of the role of metabolic disruptors in the obesity and metabolic disease epidemics, to move the field forward by assessing the current state of the science and to identify research needs on the role of environmental chemical exposures in these diseases. We propose broadening the definition of obesogens to that of metabolic disruptors, to encompass chemicals that play a role in altered susceptibility to obesity, diabetes and related metabolic disorders including metabolic syndrome.