Science, medicine, and the future. Contraception

Age, the environment and our reproductive future: bonking baby boomers and the future of sex

There has never been a greater need for scientists trained in reproductive science. Most developed countries are witnessing unprecedented rates of recourse to assisted conception sitting cheek-by-jowl with high rates of induced abortion. This article addresses these two incongruous faces of reproductive healthcare. Every year at least 44 million abortions are performed worldwide, many under unsafe and insanitary conditions that carry a significant risk to the lives of women deprived of safe, effective methods for controlling their fertility. Although birth control is a complex issue involving myriad social and political factors, the technical vacuum in this area is significant. Through no fault of the family planning authorities, there have been no radically new methods of fertility control since the oral contraceptive pill was introduced in 1960 and even this contribution to planned parenthood has its roots in the biochemistry of the 1920s and 1930s. Moreover, the pharmaceutical industry has, by and large, turned its back on fundamental research activities in this area. At present, our major investment in reproductive healthcare involves treating ever-increasing numbers of couples with assisted reproductive technologies (ART). However, these treatments are often delivered without critically considering the underlying causes of this condition or seriously contemplating the long-term consequences of the current enthusiasm for such therapy. Significantly, the clinical factors underpinning the commitment of couples to ART include advanced maternal age and a variety of lifestyle factors, such as smoking and obesity, which are known to compromise the developmental potential of the oocyte and DNA integrity in spermatozoa.

Urinary estrogen levels in women on contraceptives in enugu, South-East Nigeria

BACKGROUND

Substantial evidence supports a causal relationship between the risk of human breast cancer and levels of endogenous estrogens.

AIM

To evaluate the urinary estrogen of women on contraceptives and also compare the levels in two different classes of contraceptives; hence, the possible predisposition of such women to the risk of breast cancer.

SETTING AND DESIGN

Urinary estrogen level was evaluated in 84 women attending family planning clinic in University of Nigeria Teaching Hospital Enugu, Nigeria, who have been on contraceptive device for 10 years or less (≤10 years). They were aged between 21 and 50 years and were divide into three groups (21-30 years, 31-40 years, and >40 years). The control group consisted of 30 age-matched apparently-healthy women who were not on any contraceptive device.

MATERIALS AND METHODS

Estrogen was analyzed using Ecologenia(;) Estrogen (E1/E2/E3) microplate enzyme-linked immunosorbent assay (ELISA) kit, Batch No. T2GR4, from Japan Envirochemicals Ltd, Japan.

STATISTICAL ANALYSIS USED

Significant differences between means were determined by two-tailed Student's t-test using graph pad prism computer software program.

RESULT

There was a statistically significant increase (P=0.0462), in the mean urinary estrogen level of women on contraceptives when compared with the control. The highest amount of estrogen was excreted by the women in the 21-30 years age group. When the contraceptive devices were divided into two classes of intra-uterine device and oral/injectables, there was no statistical difference (P=0.8112) in the mean urinary estrogen output of the women.

CONCLUSION

The synthetic estrogen content of contraceptive device most probably contributed to the level excreted in the urine. The increased estrogen output observed in women on contraceptive device was not dependent on the class of contraceptive device used.

Steroid receptor expression in the vulvar vestibular mucosa — effects of oral contraceptives and menstrual cycle

BACKGROUND

The objective was to evaluate the influence of combined oral contraceptives (COC) and of the menstrual cycle on the steroid receptor expression in the vulvar vestibular mucosa of healthy women.

STUDY DESIGN

Forty-five healthy women (20 with COC and 25 without) were included. Vestibular biopsies were obtained during the menstrual cycle. Estrogen receptors (ER) alpha and beta, progesterone receptors (PR) A and B, glucocorticoid receptor and androgen receptor as well as the proliferation marker Ki67 were analyzed using immunohistochemistry followed by computerized image analysis.

RESULTS

The vestibular stromal tissue of women using COC expressed more ERbeta (p=.024) than that of women without COC. In the follicular phase, PRB was more abundant in the stromal tissue than in the luteal phase (p=.01).

CONCLUSIONS

ERbeta is more abundant in the vulvar vestibular mucosa of women using COC than in that of women without COC. There is a cyclic variation in PRB in the vestibular mucosa in healthy women without COC.

The vulval vestibular mucosa?morphological effects of oral contraceptives and menstrual cycle

BACKGROUND

An erythematous and hypersensitive vestibular mucosa has been observed during the use of combined oral contraceptives (COC). Hormonal effects on the vestibular morphology have not been studied.

OBJECTIVES

Our aim was to evaluate the morphology of the vulval vestibular mucosa during the influence of COC and during the menstrual cycle.

METHODS

Forty-five healthy women (20 using COC and 25 not using COC) were included. A 6-mm punch biopsy was obtained from the right posterior vestibule on days 7-11 of the menstrual cycle. A corresponding biopsy was taken 2 weeks later in 16 women without COC. The epithelial morphology was estimated by measuring interdermal papilla distance, dermal papilla to surface, from basal layer to surface and width of dermal papillae. A histopathological assessment was made.

RESULTS

The vulval vestibular mucosa of women using COC displayed a larger distance between the dermal papillae (P = 0.04) and a larger space from the dermal papillae to the epithelial surface (P = 0.03) compared with controls in the follicular phase. Women without COC displayed a larger interdermal papilla distance in the luteal phase compared with the follicular phase, P = 0.02. Histopathology showed more superficial blood vessels in the COC users (P < 0.01).

CONCLUSIONS

The vulval vestibular mucosa of women with COC display an altered morphological pattern with shallow and sparse dermal papillae compared with the follicular phase. Similar findings are seen in women without COC during the luteal phase which indicate a gestagenic effect on the mucosa. Associations between the morphological pattern and changes in mucosal mechanical sensitivity require further studies.

Contraception today

Modern contraceptive methods represent more than a technical advance: they are the instrument of a true social revolution-the "first reproductive revolution" in the history of humanity, an achievement of the second part of the 20th century, when modern, effective methods became available. Today a great diversity of techniques have been made available and-thanks to them, fertility rates have decreased from 5.1 in 1950 to 3.7 in 1990. As a consequence, the growth of human population that had more than tripled, from 1.8 to more than 6 billion in just one century, is today being brought under control. At the turn of the millennium, all over the world, more than 600 million married women are using contraception, with nearly 500 million in developing countries. Among married women, contraceptive use rose in all but two developing countries surveyed more than once since 1990. Among unmarried, sexually active women, it grew in 21 of 25 countries recently surveyed. Hormonal contraception, the best known method, first made available as a daily pill, can today be administered through seven different routes: intramuscularly, intranasally, intrauterus, intravaginally, orally, subcutaneously, and transdermally. In the field of oral contraception, new strategies include further dose reduction, the synthesis of new active molecules, and new administration schedules. A new minipill (progestin-only preparation) containing desogestrel has been recently marketed in a number of countries and is capable of consistently inhibiting ovulation in most women. New contraceptive rings to be inserted in the vagina offer a novel approach by providing a sustained release of steroids and low failure rates. The transdermal route for delivering contraceptive steroids is now established via a contraceptive patch, a spray, or a gel. The intramuscular route has also seen new products with the marketing of improved monthly injectable preparations containing an estrogen and a progestin. After the first device capable of delivering progesterone directly into the uterus was withdrawn, a new system releasing locally 20 microg evonorgestrel is today marketed in a majority of countries with excellent contraceptive and therapeutic performance. Finally, several subcutaneously implanted systems have been developed: contraceptive "rods," where the polymeric matrix is mixed with the steroid and "capsules" made of a hollow polymer tube filled with free steroid crystals. New advances have also been made in nonhormonal intrauterine contraception with the development of "frameless" devices. The HIV/AIDS pandemic forced policy makers to look for ways to protect young people from sexually transmitted diseases as well as from untimely pregnancies. This led to the development of the so-called dual protection method, involving the use of a physical barrier (condom) as well as that of a second, highly effective contraceptive method. More complex is the situation with antifertility vaccines, still at a preliminary stage of development and unlikely to be in widespread use for years to come. Last, but not least, work is in progress to provide effective emergency contraception after an unprotected intercourse. Very promising in this area is the use of selective progesterone receptor modulators (antiprogestins).

Antiprogestin-releasing intrauterine devices: a novel approach to endometrial contraception

Intrauterine devices (IUDs) that release progestins are highly effective contraceptives, but they induce breakthrough bleeding that some women find unacceptable. Because progesterone (P) antagonists [antiprogestins (APs)] are known to suppress the endometrium, induce amenorrhea and inhibit fertility, AP-releasing IUDs (AP-IUDs) may provide an effective contraceptive that also controls endometrial bleeding. Here, we assessed the effects of empty (blank) vs. AP-IUDs (ZK 230 211) on bleeding patterns and endometrial growth in ovariectomized, artificially cycled macaques. The AP-IUDs (but not the blank controls) induced extended, frank menstruation when inserted during the late luteal phase, an indication of local AP action. Over time, endometrial glandular and arterial proliferation were inhibited, steroid receptors were elevated, spiral arteries showed degenerative changes, P withdrawal bleeding was prevented, and estradiol (E(2))-dependent proliferation was suppressed by the AP-IUDs. In sum, AP-IUDs suppressed the effects of P on endometrial progestational development and blocked the effects of E(2) on endometrial proliferation, as previously shown for systemic treatment with APs. Therefore, AP IUDs may provide novel contraceptive devices with minimal breakthrough bleeding.

Unintended pregnancy and use of emergency contraception among a large cohort of women attending for antenatal care or abortion in Scotland

BACKGROUND

Unintended pregnancy is common. Although many unintended pregnancies end in induced abortion, up to a third of those proceeding to birth might be unplanned. Some of these pregnancies could be prevented by emergency contraception. We have sought to establish how many pregnancies ending in either childbirth or abortion are unintended, and what proportion of women use emergency contraception to try to prevent pregnancy.

METHODS

2908 women who attended an Edinburgh hospital for antenatal care and 907 attending for abortion fully completed a self-administered questionnaire including a validated measure of pregnancy intention and questions about emergency contraceptive use.

FINDINGS

814 (89.7%) of 907 pregnancies among women requesting abortion were unintended compared with only 250 (8.6%) among 2908 women who planned to continue pregnancy. However, only 1909 (65.6%) of continuing pregnancies were intended. The rest of the women were ambivalent about pregnancy intention. In women who continued with their pregnancies intendedness was related to age, with unintended pregnancy most probable in young women (p<0.0001). Emergency contraception was used by 113 (11.8%) of women who requested abortion but only 40 (1%) of those planning to continue pregnancy. In those whose pregnancy was continuing, the proportions reporting use of emergency contraception were higher in young women than in older women and in those who reported that their pregnancies were unintended than in those who meant to become pregnant (both p<0.0001).

INTERPRETATION

Unintended pregnancy is common, even among women planning to continue pregnancy. However, EC use is low even among women with no intention of conceiving, and is thus unlikely to reduce unintended pregnancy rates. Rather, we need to find ways to improve the use of regular contraception.

Steroid receptor expression in vaginal epithelium of healthy fertile women and influences of hormonal contraceptive usage

BACKGROUND

The objective of this study was to evaluate whether long-term usage of hormonal contraceptives modifies the steroid receptor expression in the human vaginal epithelium of healthy young women.

METHODS

In a cross-sectional study, three groups of hormonal contraceptive users [combined oral contraceptives (COCs), levonorgestrel implants (LNG) and depot medroxyprogesterone acetate injections (DMPAs)] were compared to controls. Fifteen subjects (20-34 years) were enrolled to each group. Vaginal biopsies were collected at two occasions from each subject, and serum concentrations of E(2) and progesterone were measured. Monoclonal antibodies directed against progesterone receptors (PRs) and estrogen receptors (ERs) were used in immunohistochemistry on formalin-fixed tissue sections of vaginal mucosa. A program for immunohistomorphometric quantification was devised to estimate frequency of epithelial steroid receptor-expressing cells.

RESULTS

Progesterone receptor expression was markedly down-regulated and significantly reduced in DMPA users compared to controls, COC and LNG users. In DMPA users, the ER expression was significantly elevated in the first compared to the second sample, and significantly elevated compared to LNG users. Estradiol concentration in serum was significantly reduced in hormonal contraceptive users compared to controls.

CONCLUSIONS

Steroid receptor expression in human vaginal epithelium is altered by long-term use of DMPA compared to controls.

Effects of mifepristone on vascular endothelial growth factor and thrombospondin-1 mRNA in Ishikawa cells: Implication for the endometrial effects of mifepristone

Mifepristone has been used for both medical termination of pregnancy and emergency contraception. Mifepristone may have both an antiovulatory activity and an antiproliferative effect on the endometrium. We have evaluated the effect of mifepristone on vascular endothelial growth factor (VEGF) and thrombospondin-1 (TSP-1) using Ishikawa cells in vitro. Mifepristone, progesterone and 17beta-estradiol at concentrations of 1.0, 0.1 and 0.01 microM, were added to confluent cells and further cultured for additional 24 h. Total RNA was extracted from control and treated cells. After reverse transcription, VEGF, TSP-1 and beta-actin cDNAs were amplified with polymerase chain reaction spiked with 33p-dCTP. The relative abundance of VEGF 121 and 165 isoforms and TSP-1 mRNA were measured by scintillation spectroscopy. Mifepristone and progesterone did not stimulate VEGF mRNA 121 and 165 isoforms, while 17beta-estradiol increased both VEGF isoforms. Mifepristone did not stimulate TSP-1 mRNA at any concentration, but progesterone increased TSP-1 mRNA, and this effect was inhibited with mifepristone. 17beta-Estradiol did not increase TSP-1 expression. We hypothesized, based on these data, that the clinical finding of endometrial antiproliferative effect and low vaginal bleeding rate observed in women using mifepristone may be related to lack of stimulation of these angiogenic factors.

A single dose of mifepristone (200 mg) in the immediate preovulatory phase offers contraceptive potential without cycle disruption

A single dose of mifepristone is an effective emergency contraceptive and has potential as a regular "once-a-month" pill. If given in the early luteal phase, the formation of a secretory endometrium is inhibited or delayed and implantation of the embryo prevented. We have explored the effect of giving the mifepristone just prior to ovulation on the ovarian and endometrial cycle. Seven women with regular menstrual cycles were studied during a control cycle and then in a second cycle when 200 mg mifepristone was given within 24 h of ovulation, i.e., when luteinizing hormone (LH) in serum was >15 IU/L and the dominant follicle was >18 mm. Ovulation was confirmed within 48 h by ultrasound in five of the seven women. The remaining two women had luteinized unruptured follicle. Following mifepristone, menses occurred after a normal luteal phase compared to control cycle (13.7 +/- 0.7 vs. 13.7 +/- 0.9 days). In all subjects the endometrium on LH + 6 in the treatment cycle showed no, or very little, secretory changes, suggesting it was unlikely that pregnancy would have occurred. We conclude that mifepristone could be given as a "once-a-month" contraceptive pill without causing significant disruption in the menstrual cycle in the majority of women for a 4-day period from just prior to ovulation until LH + 3.

Contraceptive vaccines

The control of human fertility would be revolutionised by the development of a safe, effective, long-acting contraceptive vaccine. The pursuit of this objective has involved the selection of appropriate targets within the reproductive process that are amenable to interference with antibodies. To date, three major targets have been researched. The zona pellucida (ZP) plays key roles in folliculogenesis, fertilisation and early development, and is comprised of powerful cell-specific antigens. The induction of infertility requires high ZP antibody titres that are difficult to maintain without inducing ovarian pathology characterised by a premature loss of primordial follicles. As a premature menopause would be a high price to pay for long-term contraception, this approach to a vaccine cannot progress until the cause of the ovarian pathology has been resolved. Sperm surface antigens represent another promising approach to contraceptive vaccine development. While there is some clinical data to support the likely efficacy of this strategy, none of the gamete-specific molecules characterised to date have fulfilled this promise. Anti-human chorionic gonadotropin (hCG) vaccines terminate pregnancy by preventing the maternal recognition of pregnancy. This vaccine has reached the stage of clinical trials, and preliminary indications are that the approach is safe and potentially effective. However, reliability may be an issue, given the observed inter-individual variability in antibody generation. The future of contraceptive vaccine development will clearly involve a continuation of the intense search for suitable targets and the development of improved immunisation procedures that exploit the latest innovations in vaccine technology.

Effect of long-term treatment with low-dose mifepristone on the endometrium

BACKGROUND

Mifepristone in low daily doses has contraceptive potential by inhibiting ovulation and menstruation. Because follicular development is maintained, the endometrium is exposed to estrogen for prolonged periods unopposed by progesterone.

METHODS

Endometrial biopsies were collected from 90 women in Edinburgh and Shanghai before (late proliferative) and 60 and 120 days after taking 2 or 5 mg mifepristone per day for 120 days.

RESULTS

Ovulation and menstruation were inhibited in >90% of cycles and estrogen production was similar to that observed during the follicular phase of the control cycle. By 120 days, endometrial thickness increased significantly in women in Edinburgh but decreased in Shanghai. Endometrial histology showed inactive proliferative or cystic changes with dense stroma. There was a significant decrease in markers of proliferation, i.e. mitotic index and Ki67 staining. There were no pregnancies in a total of 200 women-months in 50 sexually active women who used no other method of contraception.

CONCLUSIONS

We confirm that ovulation and menstruation were suppressed in the majority of cycles and there was asynchrony between ovarian activity and endometrial histology, which showed no signs of hyperplasia or atypia. These preliminary data suggest that daily low-dose mifepristone is potentially a safe estrogen-free contraceptive pill which has the added health benefit of amenorrhoea.

New developments in contraceptive drugs for use by women

Since the oral contraceptive pill was first marketed in 1959, advances in contraceptive drugs for women have been limited to variations on the theme of oestrogen in combination with progestogen or progestogen alone. Alterations to the pill regimen, new progestogens and new delivery systems have increased choice but while these advances significantly improve acceptability, side effects and risks remain essentially unchanged. New ideas are in short supply. Antiprogesterones offer a new approach with a variety of dose regimens but their development has been seriously hampered by the politics associated with their abortifacient action. Other hormone antagonists as contraceptives seem a long way off. Immunocontraception is still at a very early stage. Genes, whose products are uniquely concerned with reproductive processes, promise new targets but radically new contraceptive drugs for women appear distant.

Role of endogenous opioid peptides in mediating progesterone-induced disruption of the activation and transmission stages of the GnRH surge induction process

How progesterone blocks the E2-induced GnRH surge in females is not known. In this study we assessed whether the endogenous opioid peptides (EOPs) that mediate progesterone negative feedback on pulsatile GnRH secretion also mediate the blockade of the GnRH surge. We treated ovariectomized ewes with physiological levels of E2 and progesterone to stimulate and block the GnRH surge, respectively, using LH secretion as an index of GnRH release. A pilot study confirmed that blocking opioidergic neurotransmission with the opioid receptor antagonist, naloxone (NAL; 1 mg/kg.h, i.v.), could prevent the suppression of pulsatile LH secretion by progesterone in our model. By contrast, antagonizing EOP receptors with NAL did not restore LH surges in ewes in which the E2-induced GnRH surge was blocked by progesterone treatment during the E2-dependent activation stage (Exp 1) of the GnRH surge induction process. However, in ewes treated with progesterone during the E2-independent transmission stage (Exp 2), NAL partially restored blocked LH surges, as indicated by increased fluctuations in LH that, in some cases, resembled LH surges. We conclude, therefore, that the EOPs that mediate progesterone negative feedback on pulsatile GnRH secretion are not involved in blockade of activation of the E2-induced GnRH surge by progesterone, but do appear to be part of the mechanism by which progesterone disrupts the transmission stage.

Contraception

The supremacy of combined oral contraceptives (OCs) is being challenged. For too long combined OCs have been seen as synonymous with contraception, helping to maintain ignorance of alternative methods. Further, the efficacy of these OCs and condoms is often compromised by incorrect or inconsistent use. We particularly welcome developments in male systemic methods, that allow men to share not only in conception but also in contraception, and methods that are completely forgettable once instituted, especially if usable by adolescents.

Family planning perspectives at the beginning of the next century

Looking back over the past 40 years or so, family planning has indeed been the success story of development; it has made an extraordinary difference to the lives of tens of millions of women. Globally speaking, the unmet needs for family planning and reproductive health still exist. Meeting these challenges would require better and improved methods of contraception, addressing issues such as sexually transmitted infections, unsafe abortions, cultural, religious, legal and political barriers. Better utilization of communication channels and investment in 'human capital'--informing people, opening a dialogue to reach consensus for action, are crucial. Finally, changes at policy and administrative level, including improvements in financial and human resource management, and making family planning and reproductive health programs sustainable will be important as we move into the 21st century.