ISSN:0029-7828    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0029-7828    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

OBJECTIVEOur purpose was to determine the risk of pregnancy after tubal sterilization for common methods of tubal occlusion.STUDY DESIGNA multicenter, prospective cohort study was conducted in U.S. medical centers. A total of 10,685 women who underwent tubal sterilization was followed up for 8 to 14 years. The risk of pregnancy was assessed by cumulative life-table probabilities and proportional hazards models.RESULTSA total of 143 sterilization failures was identified. Cumulative 10-year probabilities of pregnancy were highest after clip sterilization (36.5/1000 procedures) and lowest after unipolar coagulation (7.5/1000) and postpartum partial salpingectomy (7.5/1000). The cumulative risk of pregnancy was highest among women sterilized at a young age with bipolar coagulation (54.3/1000) and clip application (52.1/1000).CONCLUSIONSAlthough tubal sterilization is highly effective, the risk of sterilization failure is higher than generally reported. The risk persists for years after the procedure and varies by method of tubal occlusion and age. (Am J Obstet Gynecol 1996;174:1161-70.)

ISSN:0029-7828    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0029-7828    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0029-7828    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0029-7828    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0029-7828    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0029-7828    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

The major effect of all intrauterine devices (IUD) is to induce a local inflammatory reaction in the endometrium whose cellular and humoral components are released into the uterine cavity. This inflammatory reaction has a variable effect on the reproductive strategy of the species studied. For example, this foreign body reaction can be localized within the uterus of rodents; and in farm animals it can have striking extrauterine effects. Thus, the action of IUDs in humans cannot be discerned from animals.In humans, copper ions released from Cu-IUDs enhance the inflammatory response and reach concentrations in the luminal fluids of the genital tract that are toxic for spermatozoa and embryos. In women using the IUD, the entire genital tract seems affected, at least in part, because of luminal transmission of the fluids that accumulates in the uterine lumen. This affects the function or viability of gametes, decreasing the rate of fertilization and lowering the chances of survival of any embryo that may be formed, even before it reaches the uterus.Studies on the recovery of eggs from women using IUDs and from women not using contraception show that embryos are formed in the tubes of IUD users at a much lower rate compared with nonusers. This is believed to be the major action of IUDs. Therefore, the common belief that the major mechanism of action of IUDs in women is through destruction of embryos in the uterus (i.e., abortion) is not supported by the available evidence.In Cu-IUD users, it is likely that few spermatozoa reach the distal segment of the fallopian tube, those that encounter an egg may be in poor condition. Thus, the few eggs that are fertilized have little chance for development and their possibility for survival in the altered tubal milieu become worse as they approach the uterine cavity.

ISSN:0029-7828    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0029-7828    

出版商:OVID    

年代:1996

数据来源: OVID