Ovarian function with the contraceptive vaginal ring or an oral contraceptive: a randomized study

BACKGROUND: The effects on ovarian function of the combined contraceptive vaginal ring NuvaRing and a combined oral contraceptive (COC) were compared. METHODS: This randomized, open-label study was performed in 40 healthy female volunteers, who were randomized by a computer-generated list after stratification for the ovulation day in a pretreatment cycle. They received two cycles of NuvaRing (21 subjects) or a COC (30 microg ethinylestradiol and 150 microg levonorgestrel, 19 subjects). NuvaRing was started on cycle day 5, COC on cycle day 1. Follicular diameter, endometrial thickness and FSH, LH, 17beta-estradiol (E2) and progesterone concentrations were determined. RESULTS: The median maximum follicular diameter (maxFD) was < or =11 mm during treatment. In the first treatment cycle the maxFD was lower in the COC than in the NuvaRing group, due to the different starting procedures. MaxFD were not different in the second treatment cycle. In both groups, E2 and progesterone levels remained low during treatment. Ovulations did not occur. CONCLUSIONS: In both groups, ovarian activity was adequately suppressed. Due to the different starting procedures, lower ovarian activity was observed in the COC group in the first treatment cycle. In the second cycle, ovarian suppression was comparable with NuvaRing and COC treatment.     

Effects on cycle control and bodyweight of the combined contraceptive ring, NuvaRing, versus an oral contraceptive containing 30 microg ethinyl estradiol and 3 mg drospirenone

BACKGROUND: The objective of this study was to compare cycle control, cycle-related characteristics and bodyweight effects of NuvaRing with those of a combined oral contraceptive (COC) containing 30 microg of ethinyl estradiol and 3 mg of drospirenone. METHODS: A randomized, multicentre, open-label trial in which 983 women were treated (intent-to-treat population) with NuvaRing or the COC for 13 cycles. RESULTS: Breakthrough bleeding or spotting during cycles 2-13 was in general less frequent with NuvaRing than that with the COC (4.7-10.4%) and showed a statistically significant odds ratio of 0.61 (95% confidence interval: 0.46, 0.80) with longitudinal analysis. Intended bleeding was significantly better for all cycles with NuvaRing (55.2-68.5%) than that with the COC (35.6-56.6%) (P < 0.01). Changes from baseline in mean bodyweight and body composition parameters were relatively small for both groups with no notable between-group differences. CONCLUSION: NuvaRing was associated with better cycle control than the COC, and there was no clinically relevant difference between the two groups in bodyweight.     

Oral contraceptives and venous thromboembolic disease. Analyses of the UK General Practice Research Database and the UK Mediplus database

The results of three independent studies of venous thromboembolic disease (VTE) and oral contraceptives are reviewed together with two further cohort/case-control studies which we conducted using the MediPlus and General Practice Research Database (GPRD) databases. These latter studies jointly involved 395 cases and uniquely examined the association between VTE and individual combined oral contraceptive (COC) formulations. The two studies yielded very similar results. Crude incidence rates for idiopathic VTE of 4.6 and 3.8 were found per 10,000 exposed woman-years (EWY), in the MediPlus and GPRD studies respectively. Incidence rates increased markedly with age, and in both databases the rates amongst users of levonorgestrel products were lower than those amongst users of desogestrel and gestodene products. A case fatality rate of 3% and a mortality rate of 10 per million EWY were estimated. Odds ratios (OR) were calculated for confounding variables and different COC formulations. Both database studies indicated an excess of current smokers and women with high body mass indices amongst cases. There were significantly more cases with asthma in the GPRD study and cases who had been using their COC for less than a year. No statistically significant differences between COC formulations were found in the analyses where controls were matched to cases by practice and year of birth in both the MediPlus and GPRD studies. In the GPRD study we also ran a study where controls were matched by practice and within 5 year age bands. In this study the OR were consistently higher for the newer or 'third generation' products than when controls were matched by year of birth. However only the acne formulation/OC containing cyproterone acetate and 35 microg ethinyloestradiol yielded a significant OR of 2.3. It may be concluded that improvements in prescribing are paramount as the results strongly indicate that overweight women and those who smoke are at a greater risk of VTE. Further study is required to elucidate the possibility that asthma or its treatment may predispose to VTE, alone or in combination with other risk factors. However, neither the MediPlus nor GPRD studies indicate that any one COC formulation poses a greater risk of VTE than another.     

Follicular growth during contraceptive pill or vaginal ring treatment depends on the day of ovulation in the pretreatment cycle

BACKGROUND: The aim of this study was to investigate whether the day of ovulation and the duration of a pretreatment cycle were related to the degree of follicular growth during subsequent contraceptive treatment. METHODS: This randomized, open-label study was performed in 40 healthy female volunteers, who were randomized by a computer-generated list after stratification for the ovulation day in a pretreatment cycle. They received two cycles of NuvaRing (21 subjects) or a combined oral contraceptive (COC) containing 30 microg ethinylestradiol and 150 microg levonorgestrel (19 subjects). Follicular diameter and serum hormone concentrations (FSH, LH, 17beta-estradiol, progesterone) were measured every third day. Data from treatment day 20 onwards were used for analysis. RESULTS: In the NuvaRing users, subjects with short cycles and early ovulations in the pretreatment cycle developed larger follicles during treatment than subjects with longer cycles and late ovulations. In the COC users, subjects with early ovulations in the pretreatment cycle developed larger follicles during treatment. CONCLUSIONS: The degree of follicular growth during treatment with a combined hormonal contraceptive is influenced by the duration of the pretreatment cycle and particularly by the duration of the follicular phase.     

Metformin versus oral contraceptive pill in polycystic ovary syndrome: a Cochrane review

BACKGROUND: The object of this review was to compare metformin versus oral contraceptive pill (OCP) treatment in polycystic ovary syndrome. METHODS: A systematic review and meta-analysis employing the principles of the Cochrane Menstrual Disorders and Subfertility Group was undertaken. RESULTS: Four randomized controlled trials (RCTs) (104 subjects) were included. Limited data demonstrated no evidence of a difference in effect between metformin and the OCP on hirsutism, acne or development of type 2 diabetes mellitus. There were no trials assessing diagnosis of cardiovascular disease or endometrial cancer. Metformin, in comparison with the OCP, was less effective in improving menstrual pattern [Peto odds ratio (OR) 0.08, 95% confidence interval (CI) 0.01-0.45) and in reducing the serum total testosterone level weighted mean difference (WMD) 0.54, 95% CI 0.22-0.86] but more effective in reducing fasting insulin (WMD -3.46, 95% CI - 5.39 to -1.52) and not increasing fasting triglyceride (WMD -0.48, 95% CI - 0.86 to -0.09) levels. Limited data demonstrated no evidence of a difference in effect between the two therapies on reducing fasting glucose or total cholesterol levels and severe adverse events. CONCLUSIONS: The limited RCT evidence to date does not show adverse metabolic risk with the use of the OCP compared with metformin. Further long-term RCTs are required.     

Oral contraceptive use in relation to age at menopause in the DOM cohort

BACKGROUND: We investigated the hypothesis that long-term use of oral contraceptives (OCs), in particular high-dose OCs, could postpone age at menopause. METHODS: Data was used from 8701 women who participated in a breast cancer screening programme in Utrecht (DOM-3 cohort), and who did not use hormone replacement therapy (HRT) or OCs in the 4 years prior to their last menses. Data on OC-use, menopausal status, age at menopause, year of birth, parity, smoking behaviour, socio-economic status, body mass index and age at menarche was available. Use of high-dose OCs has been defined in this study as OC-use before 1972. The data was analysed by means of linear regression and Cox's proportional hazards analysis. Women still menstruating, women with surgical menopause and women lost to follow-up were censored at their last known date of menstruation. Endpoint was the natural menopause (n = 4589). RESULTS: The use of high-dose OCs advanced the onset of menopause by approximately 1.2 months for every year of OC-use compared with no OC-use. High-dose OC-use for > or = 3 years, adjusted for confounding variables, increased the risk of earlier menopause compared with no OC-use (adjusted hazard ratio 1.12; 95% CI 1.03--1.21). The use of lower dose OCs did not increase the risk of earlier menopause (adjusted hazard ratio 1.00; 95% CI 0.91--1.09). CONCLUSIONS: These results are inconsistent with the hypothesis that long-term use of OCs could postpone the onset of menopause by inhibiting follicle depletion. Possible explanations are discussed.     

Serum levels of pregnancy-associated endometrial {alpha}-globulin ( {alpha}-PEG) during normal menstrual and combined oral contraceptive cycles and relationship to immunohistologiacl localization

Serum levels of pregnancy-associated endometrial 2-globulin(2-PEG), the major secretory protein of the endometrium duringthe late luteal phase of the menstrual cycle and early pregnancy,were measured serially during normal menstrual cycles and inwomen taking various combined oral contraceptives. Pill userswere also sampled on an individual basis. Endometrium from womentaking the combined oral contraceptive was examined immunohistochemicallyusing a monoclonal antibody to 2-PEG. Levels of 2-PEG in themenstrual cycle sera showed consistent changes following theluteinizing hormone peak, with a greater than three-fold increasebetween basal levels at midcycle and those in the late lutealphase. Serum levels of 2-PEG in the pill users remained at basallevels throughout the cycle, regardless of the progestagen inthe formulation. This finding was noted in serial and individualsamples from both monophasic and triphasic preparations. However,there was evidence of induction of 2-PEG production at the localendometrial level when immunohistochemical staining was employedat various stages of the pill cycle. This suggests that serumlevels of 2-PEG may not necessarily reflect local endometrialproduction of the protein. These observations are discussedwith reference to the proposed value of serum measurement ofthis protein in assessing relative progestagenic activity uponthe endometrium     

A randomized double-blind placebo-controlled study to assess the effect of oral contraceptive pills on the outcome of medical abortion with mifepristone and misoprostol

This was a randomized double-blind placebo-controlled trial to determine the effect of oral contraceptive (OC) pills taken immediately after medical abortion on the duration of bleeding and complete abortion rate. Two hundred women in the first 49 days of pregnancy were given 200 mg mifepristone orally followed by 400 microg misoprostol vaginally 48 h later. One day later, they were randomized to receive either OC pills (30 microg of ethinyl oestradiol and 0.15 mg of levonorgestrel per tablet) or placebo for 21 days. The complete abortion rates were 98% in the OC group and 99% in the placebo group. The median duration of bleeding was similar: 17 (range: 5-57) days in the OC group and 16 (range: 6-55) days in the placebo group. In the OC group there was a small but significant fall in the haemoglobin concentration by 14 days (5.3 g/dl) after administration of mifepristone. The incidence of side-effects was similar in the two groups. We conclude that the use of OC pills does not decrease the duration of bleeding after medical abortion nor does it affect the abortion rate.     

A comparative randomized trial to assess the impact of oral contraceptive pretreatment on follicular growth and hormone profiles in GnRH antagonist-treated patients

BACKGROUND: This randomized controlled trial was designed to assess the impact of oral contraceptive (OC) scheduling with a GnRH antagonist (ganirelix) regimen on the ovarian response of women undergoing recombinant FSH (rFSH) stimulation for IVF, compared with a non-scheduled ganirelix regimen and a long GnRH agonist (nafarelin) protocol. METHODS: A total of 110 women was treated with an OC and ganirelix, 111 with ganirelix alone and 111 with nafarelin. The OC (containing 30 microg ethinylestradiol/150 microg desogestrel) was taken for 14-28 days and stopped 2 days prior to the start of rFSH treatment. Primary efficiency parameters were the number of cumulus-oocyte complexes (per attempt) and the number of grade 1 or 2 embryos (per attempt). RESULTS: In terms of follicular growth and hormone profiles, the OC-scheduled antagonist regimen mimicked the agonist regimen rather than the (non-scheduled) GnRH antagonist regimen. In the OC-scheduled GnRH antagonist group and the nafarelin group (versus the non-scheduled antagonist group), pituitary suppression was more profound at the start of stimulation (P < or = 0.001), there was a slower start of follicular growth (P < or = 0.001), longer stimulation was required (11.7 and 10.3 days respectively versus 9.4; P < or = 0.001), and more rFSH was used (2667 and 2222 IU versus 1966 IU; P < or = 0.001). In the three groups, the number of oocytes was similar (13.1, 12.9 and 11.5 respectively; not significant) as well as the number of good quality embryos (5.1, 5.7 and 5.0 respectively; not significant). CONCLUSION: OC treatment prior to the rFSH/ganirelix regimen can be successfully applied to schedule patients, although more days of stimulation and more rFSH are required than with a non-scheduled GnRH antagonist regimen.     

Effects of oral contraceptive, synthetic progestogen or natural estrogen pre-treatments on the hormonal profile and the antral follicle cohort before GnRH antagonist protocol

BACKGROUND: Steroid pre-treatments may be useful to program GnRH antagonist IVF/ICSI cycles. This prospective study assessed hormonal and ultrasound data collected during the free period after the discontinuation of three different pre-treatments to provide information on the optimal time interval required before starting stimulation. METHODS: Women were randomized to receive oral contraceptive pill (OCP) [ethinyl estradiol (E(2)) 30 microg + desogestrel 150 microg] (n = 21) or norethisterone 10 mg/day (n = 23) or 17-betaE(2) 4 mg/day (n = 25) or no pre-treatment (n = 24) for one cycle before IVF. Assessments were performed on post-treatment day (PD) 1, 3 and 5, or on spontaneous cycle day (CD) 1 and 3. RESULTS: After OCP and progestogen administration, FSH and LH concentrations shifted from strongly suppressed PD1 levels to PD5 values similar to those observed on CD1. Meanwhile, follicle sizes remained small up to PD5. In contrast, estrogen pre-treatment poorly reduced FSH levels on PD1 compared with OCP or progestogen. Consequently, follicle size was more heterogeneous. FSH rebound was maximal on PD3, whereas LH levels were slightly increased up to PD5. CONCLUSIONS: A 5-day free interval after OCP or progestogen offers the advantages of gonadotrophin recovery and homogeneous follicular cohort, whereas early FSH rebound occurring after estrogen pre-treatment argues for a short free period.     

Effect of oral contraceptive pill pretreatment on ongoing pregnancy rates in patients stimulated with GnRH antagonists and recombinant FSH for IVF. A randomized controlled trial

BACKGROUND: The objective of this randomized controlled trial was to assess the effect of oral contraceptive pill (OCP) pretreatment on the probability of ongoing pregnancy in patients treated with a GnRH antagonist for IVF. METHODS: A fixed dose of 200 IU recombinant FSH (rFSH) was started in 425 patients either on day 2 of the menstrual cycle (non-OCP group: n = 211) or 5 days after discontinuing the OCP (OCP group: n = 214). GnRH-antagonist was initiated on day 6 of stimulation, and triggering of final oocyte maturation was performed with 10,000 IU of HCG. RESULTS: Ongoing pregnancy rates per started cycle in the non-OCP and OCP group were 27.5% and 22.9%, respectively [95% confidence interval (CI) of the difference: -3.7 to +12.8]. Pregnancy loss was significantly increased in the OCP (36.4%) compared with the non-OCP group (21.6%) (95% CI of the difference: -28.4 to -2.3). CONCLUSION: Pretreatment with OCP, as compared with initiation of stimulation on day 2 of the cycle in patients treated with GnRH antagonist and recombinant FSH, appears to be associated with a not significant difference in ongoing pregnancy rates per started cycle and results in a significantly higher early pregnancy loss.     

The role of selective prescribing in the increased risk of VTE associated with third-generation oral contraceptives

In the early 1960s, it became apparent that oral contraception (OC) with oestroprogestogens increased the cardiovascular, venous thromboembolic (VTE), myocardial infarction (MI) and cerebrovascular accident (CVA) risk. The change in medical prescribing patterns, the reduction in ethinyloestradiol dosage and the use of less androgenic progestogens made prescribers confident that the risks would subsequently decrease. At the end of 1995 and early 1996, four publications called into question that optimism by showing that third-generation pills induced a two-fold increase in VTE risk compared with second-generation pills. A biological rationale was due to be announced later. Since then, re-analysis of the data has shown that the thrombotic risk factors are increased in third-generation OC users but, more importantly, that those users (unlike those using second-generation pills) are the women who have not had the opportunity of revealing a latent thrombophilia and are, therefore, at a greater risk of expressing it during third-generation OC intake. When these data are considered, the difference between second- and third-generation OC users in terms of VTE risk is completely destroyed. In addition and although the risk factors (smoking in particular) are concentrated in third-generation OC users, the MI risk is less in those users than in second-generation pill users. This is particularly true in the presence of a risk factor such as smoking. No difference in risk has been observed for CVA in the general population between second- and third-generation OC users, but once more among smoking women the risk is lower with third-generation OC.     

A prospective study of the forearm bone density of users of etonorgestrel- and levonorgestrel-releasing contraceptive implants

BACKGROUND: The aim of the study was to compare bone mineral density (BMD) before insertion and at 18 months of use of etonorgestrel- and levonorgestrel-releasing contraceptive implants. METHODS: One hundred and eleven women, 19-43 years of age, were randomly allocated to two groups: 56 to etonorgestrel and 55 to levonorgestrel. BMD was evaluated at the midshaft of the ulna and at the distal radius of the non-dominant forearm using dual-energy X-ray absorptiometry before insertion and at 18 months of use. RESULTS: There was no difference in baseline demographic or anthropometric characteristics, or in BMD of users of either model of implant. BMD was significantly lower at 18 months of use at the midshaft of the ulna in both groups of users. However, no difference was found at the distal radius. Multiple linear regression analysis showed that the variables associated with BMD at 18 months of use in both implant groups were baseline BMD, body mass index (BMI) and difference in BMI (0 versus 18 months of use). CONCLUSIONS: Women of 19-43 years of age using either one of the implants showed lower BMD at 18 months of use at the midshaft of the ulna, however, without a difference at the distal radius.     

The differential risk of oral contraceptives: the impact of full exposure history.

Previous discussions have indicated that the small increases of risk of venous thromboembolism (VTE) associated with newer combined oral contraceptives (third generation, containing desogestrel and gestodene) may be attributed to bias due to cohort effects. In a case-control analysis, this may produce an overestimate of risk of newer preparations. In 10 centres in Germany and the UK, the Transnational Study analysed data from 502 women aged 16-44 years with VTE, and from 1864 controls matched for 5-year age group and region. Information on lifetime exposure history from all subjects was added to the dataset used in previous analyses and entered into a Cox regression model with time-dependent covariates. Based on 17 622 continuous exposure episodes comprising 47 914 person-years of observation, the adjusted hazard ratio (equivalent to odds ratio, OR) of VTE for the comparison of current users of third-generation versus current users of second-generation (primarily levonorgestrel compounds) combined oral contraceptives was 0.8 (0.5 to 1.3). The OR obtained in standard case-control analysis had been 1.5 (1.1 to 2.1). Adjustment for past exposures includes more information and appears more valid than the standard cross-sectional analysis. Using this approach, the Transnational Study data show no evidence for an increased risk of VTE with third- compared with second-generation combined oral contraceptives.     

Modern use of clomiphene citrate in induction of ovulation

Clomiphene citrate is the treatment of first choice in the managementof infertility in normally oestrogenized, anovulatory women(WH0 group II). The majority of women with 'pure' anovulatoryinfertility respond to treatment with clomiphene citrate. Therates of pregnancy and miscarriage are close to those expectedin a normal fertile population. Basal hormone concentrationsdo not predict outcome. An increased body mass index is theonly factor which is consistently associated with a decreasedresponse to clomiphene citrate; it follows therefore, that weightreduction should be an important part of therapy in anovulatorywomen. According to our data, only an increased luteinizinghormone value immediately post clomiphene citrate predictedan adverse pregnancy outcome in women who conceived. Clomiphenecitrate, along with other ovulation induction therapies, cancause multiple follicular development, with a risk of ovarianhyperstimulation and multiple pregnancy. Ultrasound monitoringof treatment is important in order to choose the appropriatedose of clomiphene citrate in subsequent cycles and to minimizethe risks of hyperstimulation and multiple pregnancy. When coupleswith other factors contributing to subfertility are excluded,the cumulative conception rate continues to rise after 6 monthsof treatment with clomiphene citrate, reaches a plateau by treatmentcycle 12 and approaches that of the normal population. It hasbeen reported that prolonged use of clomiphene citrate may beassociated with an increased risk of a borderline or invasiveovarian tumour. Taking into consideration these observations,we recommend that anovulatory women responsive to clomiphenecitrate should be treated for at least 6 cycles before consideringmore complex or invasive methods of ovulation induction, andthat treatment should probably be limited to a maximum of 12cycles.     

Randomized comparison of ovulation induction with and without intrauterine insemination in the treatment of unexplained infertility

The aim of this prospective randomized controlled study wasto determine the possible role of ovulation induction with intrauterineinsemination (IUI) in the treatment of unexplained infertility.A total of 100 patients were randomized to receive ovulationinduction with or without IUI. All patients were treated withlong-course gonadotrophinreleasing hormone analogue (GnRHa),starting in the luteal phase, and exogenous follicle stimulatinghormone (FSH) to induce follicular growth. Ovulation was inducedusing human chorionic gonadotrophin and timed intercourse (TI)was advised 24–48 h later or IUI was effected 36—48h later. Both the cycle fecundities (21.8 and 8.5%) and thecumulative ongoing pregnancy rates after three cycles (42 and20%) were significantly higher (P < 0.03) in the IUI groupthan in the TI group respectively. This is a clear indicationthat ovulation induction with IUI is an effective treatmentmethod for unexplained infertility, but ovulation inductionwith TI has a negligible impact in this large group of patients.     

Salivary progesterone levels and rate of ovulation are significantly lower in poorer than in better-off urban-dwelling Bolivian women

BACKGROUND: Agriculturalists in less-developed countries (LDC) have lower progesterone levels than urban industrialized populations. However, it is unknown if urban LDC populations are also relatively lower. We tested whether urban Bolivia samples-poorer (Bol-p) and better-off (Bol-b)-have lower progesterone than a Chicago (USA) sample, and whether progesterone and rate of ovulation are lower in Bol-p than in Bol-b. METHODS: Serial salivary samples collected from Bolivians, screened according to strict exclusion criteria during two complete menstrual cycles, were radioimmunoassayed for progesterone; anthropometrics were collected at mid-follicular and mid-luteal phases. RESULTS: Progesterone levels are lower in the Bolivia samples, and higher in the Bol-b than Bol-p; ovulation rate is greater in Bol-b than Bol-p. For only ovulatory cycles, mean-follicular-P (pmol/l), mean-luteal-P (pmol/l), and mean-peak-P (pmol/l) are respectively 65, 142 and 208 in Bol-p; 76, 167 and 232 in Bol-b; and 96, 240 and 330 in Chicago. Principal components representing body-size and progesterone level are positively correlated (r = 0.404, P = 0.005). CONCLUSIONS: Progesterone levels appear to be influenced by chronic and acute ecological conditions, evidenced by the association with body-size and the probability of ovulation respectively. These findings have implications for understanding cancer aetiology, developing population-appropriate hormonal contraceptives, and modelling the evolution and functioning of the reproductive system.     

Induction of ovulation with pulsatile GnRH in hypothalamic amenorrhoea

Pulsatile administration of gonadotrophin releasing hormone(GnRH) is a very effective treatment for induction of ovulationin hypothalamic amenorrhoea (HA). Thirty-seven women have beentreated for a total of 117 cycles which resulted in 42 pregnancies–fourtreatment failures occurred. If these cycles are excluded, the42 pregnancies were obtained within 2.3 cycles. One twin pregancyoccurred and no hyperstimulation was observed. The treatmentwas administered intravenously with a dosage schedule basedon the grading of HA. We concluded that pulsatile GnRH was safeand very successful in induction of pregnancy in HA. Other indications(polycystic ovary syndrome and luteal phase defect) remain muchless suitable for this treatment.     

Association between sex hormone-binding globulin levels and activated protein C resistance in explaining the risk of thrombosis in users of oral contraceptives containing different progestogens

BACKGROUND: Epidemiological studies have shown that both the estrogen dose and progestogen type of oral contraceptives contribute to the increased risk of thrombosis in oral contraceptive users. Thrombin generation-based activated protein C (APC) sensitivity is a global test for the net prothrombotic effect of oral contraceptives and predicts the thrombotic risk. Our objective was to test the usefulness of sex hormone-binding globulin (SHBG) as a marker for the thrombotic risk of an oral contraceptive. METHODS: We measured SHBG and APC resistance in 156 healthy users of various types of oral contraceptives. RESULTS: Users of oral contraceptives with a moderately increased risk of thrombosis (gestodene and desogestrel pills) had higher SHBG levels than users of low-risk oral contraceptives containing levonorgestrel. Similarly, for higher doses of estrogen in oral contraceptives we found higher SHBG levels. Women using oral contraceptives with the highest thrombotic risk (cyproterone acetate pills) rendered the highest SHBG levels. Users of oral contraceptives containing gestodene, desogestrel or cyproterone acetate were more resistant to APC than users of levonorgestrel pills. SHBG levels were positively associated with the increased APC resistance. CONCLUSIONS: Our findings support the hypothesis that the effect of an oral contraceptive on SHBG levels might be a marker for the thrombotic risk.     

LHRH agonists in IVF: different methods of utilization and comparison with previous ovulation stimulation treatments

LHRH agonists are being increasingly used in ovulation stimulationprotocols in IVF programmes. We have compared the results oftwo methods of utilization of LHRH agonists. In the long protocol,gonadotrophin stimulation was only commenced after a preliminaryperiod of pituitary desensitization with LHRH agonist. In theshort protocol, exogenous gonadotrophins were administered shortlyafter the start of LHRH agonist therapy, benefitting from thegonadotrophin flare-up effect. One-hundred-and-eighty-six patientswere divided equally between the two treatments. There was nodifference in the ovarian response on the day of HCG or thenumber of mature oocytes recovered. The cleavage rate of matureoocytes was higher in the short protocol (70, versus 56, P<0.01). The ongoing pregnancy rate per treatment cycle was similarin both groups (18, in the long protocol and 16, in the shortprotocol). Analysis of the luteal phases revealed a trend forhigher progesterone values in the long protocol although thiswas only significant on the second day following oocyte retrieval.As the clinical results were similar other factors should betaken into account when deciding therapy. These include patientconvenience, cost and side-effects. Other schedules of ovulationstimulation using LHRH agonists are discussed.