Body composition and bone mineral density in male-to-female transsexuals during cross-sex hormone therapy using gonadotrophin-releasing hormone agonist.

OBJECTIVE: In transsexual people, cross-sex hormone therapy is an important component of medical treatment and results in a complete change in the sex hormone environment. Steroid hormones plays an important role in developing and maintaining bone mass and body composition in both sexes. The aim of this study was to evaluate changes in body composition and bone mineral density (BMD) during cross-sex hormone therapy in transsexuals using gonadotrophin-releasing hormone agonists and intramuscular oestrogens. METHODS: 84 male-to-female transsexuals (MtFs) were treated with 10 mg oestradiol-17ß valerate every 10 days. The study population was treated with subcutaneous injections of 3.8 mg goserelin acetate every 4 weeks to suppress endogenous sex hormone secretion completely. Endocrine parameters, body composition and BMD after 12 months and after 24 months were compared with baseline values. RESULTS: There was a significant decline in gonadotrophins and testosterone, while oestradiol, sex hormone-binding globulin, and high-density lipoprotein levels increased significantly after 12 and 24 months. There was a significant increase in body mass index (BMI), fat mass, and lumbar spine bone mineral density in MtFs during the study period, while lean mass decreased significantly and no effect was observed on femoral bone mineral density. CONCLUSION: There was an increase in BMI associated with a shift from lean mass to fat mass. There appears to be no risk of osteoporosis developing in MtFs when there is adequate oestrogen substitution, even in the absence of testosterone. Furthermore in comparison with hormone regimes using oral medications, the complication rates appear to be lower in patients receiving gonadotrophin-releasing hormone agonists and intramuscular oestrogens.

How good is fetal weight estimation using volumetric methods?

PURPOSE: Birth weight is an important predictive parameter for neonatal morbidity and mortality, and accurate estimation of fetal weight is therefore a valuable tool for determining the further obstetric management. Many sonographic weight formulas have been introduced. Most of these widely accepted formulas were derived from non-linear regression analysis. Only few formulas have been constructed using other methods, such as the physically based volumetric method based on routine two-dimensional biometric parameters in the fetus. The rationale for calculating fetal weight from volumetric measurements was that weight should to be directly proportional to fetal volume. In a recent review by Dudley, this method was considered to have some advantages in comparison with conventional regression formulas. However, to the best of our knowledge, none of the published volumetric formulas has ever been evaluated in a large population of fetuses. The aim of this study was to compare the volumetry-based formulas with widely accepted weight equations derived from regression analysis. We evaluated weight equations over the whole weight range and in specific weight groups in order to find out whether some equations were preferable in the groups tested. MATERIALS AND METHODS: 3975 pregnancies were included in order to evaluate four conventional formulas and four formulas based on volumetric models. The inclusion criteria were a singleton pregnancy, ultrasound examination with complete biometric parameters within 7 days before delivery, and an absence of structural or chromosomal malformations. The equations were compared over the whole weight range and in specific weight groups. RESULTS: Over the whole weight range, no single formula was able to offer a substantial advantage. In the small fetus, the Hadlock formula was preferable due to its low level of systematic error. For mid-sized fetuses, the Schild formula should be considered. In macrosomic fetuses, all formulas tended to underestimate the actual birth weight. Here, the best accuracy was achieved using the Merz formula. CONCLUSION: Neither a volumetric formula nor a conventional formula proved to be superior over the whole weight range. Within specific weight groups, some formulas showed improved accuracy. However, new approaches such as three-dimensional ultrasonography need to be pursued further in order to achieve better results in fetal weight estimation.