Endometrial thickness and oestradiol concentration in women with bleeding complaints during use of Norplant implants

Effects of progestin-only contraceptives on the endometrium

INTRODUCTION

The contraceptive activity of synthetic progestins is mediated through three basic mechanisms: (a) An anti-gonadotrophic action leading to the inhibition of ovulation; (b) Changes in cervical mucus characteristics that inhibit sperm penetration and (c) desynchronization of the endometrial picture necessary for implantation.

AREAS COVERED

Mechanisms involved in the progestin-induced endometrium desynchronization are individually reviewed for each of the routes of administration and, whenever possible, by individual members of the various families of synthetic progestin derivatives.

EXPERT OPINION

For contraceptive purposes, progestins are today administered through several routes: orally, as injections, subdermally and via the vagina or the uterine cavity. Given this variety of modalities, their effects may differ, depending on the route of administration, concentration reached at the level of the endometrium and the duration of use. These are characterized by inactivation of the endometrium. Progestin-only contraception provides a safe and effective control of fertility regulation, although, they are associated with the problem of endometrial break through bleeding that may lead to discontinuation. Unfortunately, in spite of a major research effort over two decades, there is not, as yet, an established long-term intervention available to manage bleeding irregularities, making mandatory a deeper understanding of the mechanisms involved is required.

Ovarian cysts in users of Implanon® and Jadelle® subdermal contraceptive implants

OBJECTIVE

To evaluate the prevalence of ovarian cysts in users of two contraceptive implants compared to users of intrauterine contraceptive (IUC).

MATERIALS AND METHODS

A total of 344 women were enrolled at 3 months of use of the etonogestrel-releasing implant (Implanon), the levonorgestrel-releasing implant (Jadelle) or the TCu380A IUC. Bimanual pelvic examination and vaginal ultrasound were performed during routine 3-, 6- and 12-month visits of asymptomatic women. Women with ovarian cysts (or enlarged ovarian follicles > or = 25 mm) were assessed weekly until disappearance or reduction of the image [including estradiol (E2) and progesterone (P) measurement], and women with no ovarian enlargement underwent the same evaluation for the same period of time.

RESULTS

Ovarian cysts were detected in 5.2%, 13.0% and 1.9% of users of Implanon, Jadelle and IUC, respectively, at 3 months. At 6 months of use, prevalence was 7.2%, 8.0% and 2.1%, whereas 12-month rates were 26.7%, 14.6% and 1.2% in the three groups, respectively. E2 levels were significantly higher among users with ovarian cysts than controls. The time until disappearance of the ovarian cyst was similar in all three groups. There were more cases of menorrhagia in users of implants who had ovarian cysts than in those 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.

Apoptosis, proliferation, and sex steroid receptors in postmenopausal endometrium before and during HRT

OBJECTIVES

Endometrial homeostasis, indicated as the balance between apoptosis and proliferation, was studied with regard to endometrial safety and bleeding disturbances.

MATERIALS AND METHODS

The quantitatively sufficient endometrial biopsies of 92 postmenopausal women enrolled in the study were investigated. The participants were divided into two groups, each receiving a continuous combined HRT regimen with either conjugated estrogen (CE) 0.625 mg + 5 mg medroxyprogesterone acetate (MPA) (=CE/MPA) or 17-beta-estradiol (E2) 2 mg + 1 mg norethisterone acetate (NETA) (=E2/NETA). These were evaluated according to apoptotic index (Ai) and proliferation marker Ki-67 index. Estrogen receptor alpha (ER) and progesterone receptor (PR) expression were also monitored, as well as endometrial thickness. Quantitative in situ techniques were used.

RESULTS

Ai and Ki-67 index were unchanged in epithelial glands of endometrium from baseline to second biopsy obtained after 1 year of combined continuous HRT. In stromal tissue, Ki-67 index was increased, while Ai was on the same level. PR expression in both epithelium and stroma was unchanged. Endometrial thickness was unaffected during therapy, and the histopathological evaluation showed no development of hyperplasia or carcinoma.

CONCLUSIONS

The unaffected homeostasis in endometrial epithelium contributes to endometrial safety and is in accordance with the histopathological findings of no hyperplasia. The homeostasis of stroma was transformed to be more proliferative. Increased stromal proliferation may be of importance for stromal support of the veins and for decreasing breakthrough bleeding during HRT. The increased stromal proliferation, as well as the decreased ER expression both in epithelium and stroma, could be an effect of progesterone.

Vaginal bleeding disturbances and implantable contraceptives

Implantable contraceptives allow safe and effective fertility regulation for up to 5 years. Currently available devices release low doses of progestogens. Disruption of vaginal bleeding patterns is almost inevitable, particularly during the initial months of use. Irregular and prolonged bleeding as well as amenorrhea are common. Irregular bleeding is unpopular with most women and unacceptable to some. This review describes the vaginal bleeding disturbances induced by modern implantable contraceptives and discusses the implications of these in terms of method use and discontinuations. The cause of the irregular bleeding is not fully understood, but recent evidence suggests that an increase in endometrial vascular fragility might precipitate vessel breakdown and, hence, breakthrough bleeding. This review discusses this evidence and outline the possible mechanisms underlying breakthrough bleeding associated with implantable contraceptives. In addition, therapies for bleeding disturbances are described and their efficacy reviewed.

Implantable contraception

Although levonorgestrel contraceptive implants have been available for over 15 years, innovations have only recently led to a wider choice. These new implants offer easier insertion and removal and other advantages depending on the type of progestin. Implants prevent pregnancy by several mechanisms, including inhibition of ovulation and luteal function and alteration of cervical mucus and the endometrium. The high efficacy and ease of maintenance make implants an ideal contraceptive for many women, including adolescents, a population that uses implants infrequently but reports high satisfaction. Implants are appropriate for women who are breastfeeding, who have contraindications to estrogen, or who have diseases such as diabetes, hypertension, sickle cell anemia, or an HIV infection because implants have few metabolic or hematologic effects. Long-term use has not been associated with a decrease in BMD and generally leads to increased blood levels and iron stores. Women who wish to space their pregnancies appreciate the nearly immediate onset of action with insertion and the rapid termination of all effects with removal. All types of implants lead to menstrual changes and other side effects in some women. Adverse effects that occur in implant users more than the general population include headaches and acne. Women must be thoroughly counseled regarding the potential for menstrual alteration, side effects, and sexually transmitted infections if they do not use condoms. Despite their initial high cost, implants are a cost-effective method over several years, even when discontinued before the life of the implant.

Superficial endometrial vascular fragility in Norplant users and in women with ovulatory dysfunctional uterine bleeding

The aim of this study was to develop an objective test for superficial endometrial vascular fragility at hysteroscopy, and to apply this test to women using Norplant((R)) for contraception and to women with ovulatory dysfunctional uterine bleeding (DUB). A prospective observational study was carried out in 34 Norplant users and 20 women with menorrhagia due to ovulatory DUB. Superficial endometrial vascular fragility was assessed at hysteroscopy by observing the source and extent of frank and subepithelial bleeding during controlled collapse and redistension of the uterine cavity. Superficial endometrial blood vessels were more fragile in Norplant users compared to women with DUB (chi(2) = 11.60, P = 0.02). Superficial endometrial petechiae (chi(2) = 37.9, P < 0.0001) and ecchymoses (chi(2) = 42.2, P = 0.0001) were more frequently observed in the Norplant users than in the menorrhagia group. In Norplant users, superficial endometrial vascular fragility was increased in those with frequent bleeding or spotting during the past 30 days (chi(2) = 6.15, P = 0.01), and in those who were examined during a bleeding episode (chi(2) = 5.3, P = 0.02). Fragility was increased in the menorrhagia group during the perimenstrual period (days 24 to 05; chi(2) = 12.83, P = 0.01). There was no obvious relationship between subepithelial bleeding and circulating concentrations of oestradiol and progesterone.

Correlation of endocrine profiles with bleeding patterns during use of Nestorone contraceptive implants

The relationship between ovarian hormones and bleeding patterns during continuous progestin contraception was studied in 29 women who used Nestorone (NES) releasing implants. Oestradiol and progesterone were measured in blood samples taken twice a week for 6 consecutive weeks, during months 6, 12, 18 and 24 of implant use. Retrospectively, the association between hormonal concentrations and bleeding patterns was evaluated. Twenty-four short (</= 24 days), 36 normal (25-35 days), 27 long (36-90 days) and nine episodes of amenorrhoea, as well as 28 periods of prolonged bleeding, were identified. Short cycles, periods of prolonged bleeding and amenorrhoea were characterized by low oestradiol concentrations. Bleeding after a normal or long cycle regularly occurred after a rise and fall of oestradiol or oestradiol and progesterone. The duration of bleeding was directly and significantly associated with the highest concentration of oestradiol in the previous 15 days in anovulatory cycles. Luteal activity was associated with shorter duration of bleeding. Periods of prolonged bleeding were usually initiated with a drop in oestradiol and over half ended with an increase in oestradiol. It was concluded that changes in endogenous hormone have a significant influence over the bleeding pattern during use of NES implants.

The effect of mefenamic acid on controlling irregular uterine bleeding secondary to Norplant use

The aim of this double-blind, placebo-controlled study was to evaluate the effect of mefenamic acid and placebo on controlling irregular uterine bleeding secondary to Norplant use. A total of 67 Norplant users attending the Family Planning Clinic of Chulalongkorn Hospital all had irregular bleeding. These women were randomly allocated into two groups. A total 34 users received mefenamic acid, 500 mg twice a day for 5 days, and placebos were given to the other 33 in the same manner. The total days of bleeding and spotting and the percentage of women in whom bleeding was stopped were analyzed in weeks 1 and 4. The percentage of subjects in whom bleeding was stopped during week 1 after initial treatment was significantly higher in the mefenamic acid group than the placebo group (76%, 27%; p < 0.001). In the follow-up period (4 weeks after initial treatment), a bleeding-free interval of > 20 days was found in 68% of the subjects treated with mefenamic acid and 33% treated with the placebo; the mean number of bleeding/spotting days was lower with mefenamic acid treatment (11.6 and 17.2 days; p < 0.05). The difference was statistically significant. It is concluded that mefenamic acid was more effective than placebo in short-term control of irregular bleeding and spotting associated with Norplant use.