The updated economic model has good predictive power, but validation against longer-term outcomes is still needed. Our analyses also demonstrate the importance of designing a model with sufficient flexibility such that the model allows for assessment of the impact of key sources of uncertainty on the value of DMAs.
Ovarian hyperstimulation syndrome (OHSS) remains one of the most life-threatening and potentially fatal complications of assisted reproduction treatments, arising from excessive stimulation of the ovaries by exogenous gonadotropins administrated during in vitro fertilization procedures, which is characterized by massive fluid shift and accumulation in the peritoneal cavity and other organs, including the lungs and the reproductive tract. The pathogenesis of OHSS remains obscure, and no definitive treatments are currently available. Using RT-PCR, Western blot, and electrophysiological techniques we show that cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-activated chloride channel expressed in many epithelia, is involved in the pathogenesis of OHSS. Upon ovarian hyperstimulation, rats develop OHSS symptoms, with up-regulated CFTR expression and enhanced CFTR channel activity, which can also be mimicked by administration of estrogen, but not progesterone, alone in ovariectomized rats. Administration of progesterone that suppresses CFTR expression or antiserum against CFTR to OHSS animals results in alleviation of the symptoms. Furthermore, ovarian hyperstimulation does not induce detectable OHSS symptoms in CFTR mutant mice. These findings confirm a critical role of CFTR in the pathogenesis of OHSS and may provide grounds for better assisted reproduction treatment strategy to reduce the risk of OHSS and improve in vitro fertilization outcome.
Sperm banking can preserve male fertility effectively, but the current conditions of sperm cryopreservation in China have not been investigated. This retrospective investigation was based on data collected at multiple centres in China from January 2003 to December 2008. The collected data included urogenital history, indication for cryopreservation, semen parameters, use rate, type of assisted reproductive technique (ART) treatment and pregnancy outcome. The study population included 1 548 males who had banked their semen during the study period at one of the clinics indicated above. Approximately 1.9% (30/1 548) of the cryopreserved semen samples were collected from cancer patients; about 88.8% (1 374/1 548) of the patients had banked their semen for ART and 8.6% (134/1 548) had a male infertility disease (such as anejaculation, severe oligozoospermia and obstructive azoospermia). The total use rate of cryopreserved semen was 22.7% (352/1 548), with 119 live births. The cancer group use rate was 6.7% (2/30), with one live birth by intracytoplasmic single sperm injection (ICSI). The ART group use rate was 23.2% (319/1 374), with 106 live births. The reproductive disease group use rate was 23.1% (31/134), with 12 live births. The semen parameters in each category varied; the cancer patient and infertility disease groups had poor semen quality. In vitro fertilization (IVF) and ICSI were the most common ART treatments for cryopreserved sperm. Semen cryopreservation as a salvage method is effective, but in many conditions it is underutilized, especially in cancer patients. Lack of awareness, urgency of cancer treatment and financial constraints are the main causes of the low access rate. The concept of fertility preservation should be popularized to make better use of this medical service in China.
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