Association between intrauterine device use and endometrial, cervical, and ovarian cancer: an expert review.

The intrauterine device is one of the most effective forms of contraception. Use of the intrauterine device has increased in the United States over the last 2 decades. Two formulations are commercially available in the United States: the levonorgestrel-releasing intrauterine device and the copper intrauterine device. The levonorgestrel intrauterine device releases progestin, causing endometrial suppression and cervical mucus thickening, whereas the primary mechanism of action of the copper intrauterine device is to create a local inflammatory response to prevent fertilization. Whereas the protective effects of combined hormonal contraception against ovarian and endometrial cancer, and of tubal sterilization against ovarian cancer are generally accepted, less is known about the effects of modern intrauterine devices on the development of gynecologic malignancies. The best evidence for a protective effect of intrauterine device use against cancer incidence pertains to levonorgestrel intrauterine devices and endometrial cancer, although studies suggest that both copper intrauterine devices and levonorgestrel intrauterine devices reduce endometrial cancer risk. This is supported by the proposed dual mechanisms of action including both endometrial suppression and a local inflammatory response. Studies on the relationship between intrauterine device use and ovarian cancer risk show conflicting results, although most data suggest reduced risk of ovarian cancer in intrauterine device users. The proposed biological mechanisms of ovarian cancer reduction (foreign-body inflammatory response, increased pH, antiestrogenic effect, ovulation suppression) vary by type of intrauterine device. Whereas it has been well established that use of copper intrauterine devices confers a lower risk of cervical intraepithelial neoplasms, the effect of levonorgestrel intrauterine device use on cervical cancer remains unclear. Older studies have linked its use to a higher incidence of cervical dysplasia, but more recent literature has found a decrease in cervical cancer with intrauterine device use. Various mechanisms of protection are postulated, including device-related inflammatory response in the endocervical canal and prostaglandin-mediated immunosurveillance. Overall, the available evidence suggests that both levonorgestrel intrauterine devices and copper intrauterine devices reduce gynecologic cancer risk. Whereas there is support for the reduction of endometrial cancer risk with hormonal and copper intrauterine device use, and reduction of cervical cancer risk with copper intrauterine device use, evidence in support of risk reduction with levonorgestrel intrauterine device use for cervical and ovarian cancers is less consistent.

A laparoscopic approach to cesarean scar ectopic pregnancy.

Cesarean scar pregnancies confer serious risk and severe morbidity. Appropriate management is the key to preventing complications. Although expectant management is usually contraindicated, the ideal combination of medical or surgical treatments is unclear and must be tailored to the patient's preferences and stability, provider skill, and the available resources. In this article, we present a combined medical and surgical approach that was successfully employed for the termination and excision of a cesarean scar pregnancy at 12 weeks' gestation in a patient desiring uterine preservation. A video is included, demonstrating the surgical steps of a laparoscopic approach used to safely resect the pregnancy and cesarean delivery scar with minimal blood loss. The management technique described can be utilized to effectively resolve cesarean scar pregnancy, to possibly decrease the risk of recurrence, and preserve future fertility with a minimally invasive outpatient surgery.

Cochrane Review Summaries-July 2021.

In this month's issue, the journal continues to bring new insights from Cochrane systematic reviews to the readers of Obstetrics & Gynecology. This month, we highlight the use of intrauterine progestins for the treatment of endometrial hyperplasia and an overview review of interventions to prevent gestational diabetes. The summaries are published below. The complete references with hyperlinks are listed in Box 1.

Pyrolysis biochar has negligible effects on soil greenhouse gas production, microbial communities, plant germination, and initial seedling growth.

Biochar has been promoted as a soil amendment that enhances soil quality and agronomic productivity and reduces greenhouse gas production. However, these benefits are not always realized. A major hurdle to the beneficial use of biochar is our limited knowledge regarding the mechanisms directing its effects on soil systems. This project aimed to eliminate some of this uncertainty by examining the biological responses (plant productivity, greenhouse gas production, soil microbial community structure) of a suite of soils (10) to the addition of biochars produced by different processes (pyrolysis, gasification, burning) from a range of feedstocks (corn stalks, hardwood, grass). Results indicated that these three responses were not significantly impacted by the addition of pyrolysis biochars from different feedstocks at 1 and 5% (w/w) addition levels. On the other hand, both an open-air burned corn stalk (5%) and raw corn stalks (1 and 5%) additions did alter the measured soil functionality. For example, the 5% burnt corn stalks addition reduced total above ground plant biomass (∼30%), increased observed N2O production by an order of magnitude, and altered soil bacterial community structure. The bacterial groups that increased in relative abundance in the burnt corn stalks-amended soils included families associated with cellulose decomposition (Chitinophagaceae), plant pathogens (Xanthomonadaceae), and biochar/charcoal-amended media (Gemmatimonadetes). In contrast, the abundance of these bacterial groups was not impacted by the pyrolysis biochars. Therefore, this research suggests that pyrolysis biochar represents a stabilized form of carbon that is resistant to microbial mineralization and has negligible effects on soil biological responses.

Temporal variations in the abundance and composition of biofilm communities colonizing drinking water distribution pipes.

Pipes that transport drinking water through municipal drinking water distribution systems (DWDS) are challenging habitats for microorganisms. Distribution networks are dark, oligotrophic and contain disinfectants; yet microbes frequently form biofilms attached to interior surfaces of DWDS pipes. Relatively little is known about the species composition and ecology of these biofilms due to challenges associated with sample acquisition from actual DWDS. We report the analysis of biofilms from five pipe samples collected from the same region of a DWDS in Florida, USA, over an 18 month period between February 2011 and August 2012. The bacterial abundance and composition of biofilm communities within the pipes were analyzed by heterotrophic plate counts and tag pyrosequencing of 16S rRNA genes, respectively. Bacterial numbers varied significantly based on sampling date and were positively correlated with water temperature and the concentration of nitrate. However, there was no significant relationship between the concentration of disinfectant in the drinking water (monochloramine) and the abundance of bacteria within the biofilms. Pyrosequencing analysis identified a total of 677 operational taxonomic units (OTUs) (3% distance) within the biofilms but indicated that community diversity was low and varied between sampling dates. Biofilms were dominated by a few taxa, specifically Methylomonas, Acinetobacter, Mycobacterium, and Xanthomonadaceae, and the dominant taxa within the biofilms varied dramatically between sampling times. The drinking water characteristics most strongly correlated with bacterial community composition were concentrations of nitrate, ammonium, total chlorine and monochloramine, as well as alkalinity and hardness. Biofilms from the sampling date with the highest nitrate concentration were the most abundant and diverse and were dominated by Acinetobacter.