Ovarian Cysts in Users of Two Kinds of Progestin-only Contraceptives Implants

Objective To evaluate the prevalence of functional ovarian cysts in users of two different types of contraceptive implants. Methods A total of 239 women were enrolled at 3 months of use of the etonogestrelreleasing implant （Implanon） and the levonorgestrel-releasing implant （Jadelle）. Bimanual pelvic examination and vaginal ultrasound were performed during routine 3, 6 and 12-month visits of asymptomatic women（control group）. Women with ovarian cysts （or enlarged ovarian follicles 〉25 mm） （cysts group） were assessed weekly until disappearence or reduction of the image （including estradiol （E2） and progesterone measurement and women with no ovarian enlargement underwent same evaluation for the same period of time. Results Ovarian cysts were detected in 5.1% and 13.0% of users of Implanon and Jadelle, respectively, at 3rd month. At the 6th month of use, prevalences were 7.1% and 7.8%, and at 12th month rates were 25.7% and 14.7% in the two groups, respectively. E2 levels were significantly higher in cysts group than in control group. The time until disappearance of the ovarian cyst was similar in Implanon and Jadelle group. There were more cases of menorrhagia in patients rveth ovarian cysts than in patients with no ovarian enlargement. Conclusions The finding of ovarian cysts or enlarged ovarian follicles during the first year of use of Implanon and Jadelle implants is common and transient and should not be interpreted as a pathologic ovarian cyst. No further medical interventions are necessary.

Biodegradable implants based on photo-cross-linked aliphatic polycarbonates for long-acting contraception

In this study,a new class of biodegradable contraceptive implants was prepared via the UV irradiation molding method,among which,progestin levonorgestrel(LNG)was used as a model drug.Photo-cross-linked aliphatic polycarbonates(APCs),namely,poly(trimethylene carbonate-co-2,2′-dimethyltrimethylene carbonate)[P(TMC-co-DTC)]elastomers,were used as the drug delivery matrix.The results obtained from the degradation experiments carried out in Sprague-Dawley(SD)rats showed that the cross-linked elastomer had the degradation characteristics of the surface erosion degradation mechanism,with no generation of acid degradation products,and excellent form-stability,which met the performance requirements of the matrix for a long-acting sustained-release delivery system.The in vitro cytotoxicity tests and histological and immunohistochemical evaluations showed good biocompatibility and biosafety of the elastomer matrix material and contraceptive implants.Subsequently,the implant formulations were screened by in vitro release experiments,and their release kinetics were explored.Finally,in the evaluation study of the in vivo anti-fertility effect,the implants exhibited excellent dimensional stability and were degraded by a surface erosion mechanism.LNG achieved a stable and sustained release in female SD rats,maintaining a long-acting contraceptive duration of up to 4 months.The contraceptive implants obtained in this study could be used to address the limitations of currently available formulations,which required secondary surgical removal and a single means of regulating drug release kinetics.Therefore,these implants could provide a new option for birth control needs and may be of significance in reducing the incidence of induced abortion and protecting female fertility.