[Show abstract][Hide abstract] ABSTRACT: Use of combined hormonal contraceptives is associated with a three- to eight-fold increased risk of venous thrombosis compared with non-use. The thrombotic risk depends on the estrogen dose as well as the progestogen type. Use of hormonal contraceptives leads to resistance to activated protein C (APC), which may serve as marker for the risk of venous thrombosis. Hyperthyroidism is also associated with an increased risk of venous thrombosis, due to increased free Thyroxine (FT4) levels which cause a hypercoagulable state.
The objective of this study was to evaluate the effects of hormonal contraceptives on levels of FT4, thyroid stimulating hormone (TSH) and thyroxine binding globulin (TBG), and to investigate the effects on APC resistance per contraceptive group. We measured FT4, TBG and TSH levels and APC resistance in 231 users of oral contraceptives.
Users of the most thrombogenic hormonal contraceptives, i.e. containing desogestrel, cyproterone acetate or drospirenone, had higher TBG levels than users of less thrombogenic hormonal contraceptives, i.e. the levonorgestrel-containing intrauterine device. TSH levels were not significantly elevated and FT4 levels did not change. TBG levels were also associated with APC resistance.
Use of hormonal contraceptives lead to elevated TBG levels, slightly elevated TSH levels and unchanged FT4 levels without causing a hyperthyroid state. Thus, the increased thrombotic risk during the use of hormonal contraceptives cannot be explained by a hyperthyroid state caused by use of these hormonal contraceptives.
Thrombosis Research 01/2014; 133(4). DOI:10.1016/j.thromres.2013.12.041 · 2.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Use of combined oral contraceptives is associated with a three- to six-fold increased risk of venous thrombosis. Hormonal contraceptives induce acquired resistance to activated protein C (APC), which predicts the risk of venous thrombosis. The biological basis of the acquired APC resistance is unknown. Free protein S (PS) and free tissue factor pathway inhibitor (TFPI) are the two main determinants of APC. Our objective was to assess the effect of both hormonal and non-hormonal contraceptives with different routes of administration on free TFPI and free PS levels. We conducted an observational study in 243 users of different contraceptives and measured APC sensitivity ratios (nAPCsr), free TFPI and free PS levels. Users of contraceptives with the highest risk of venous thrombosis as reported in recent literature, had the lowest free TFPI and free PS levels, and vice versa, women who used contraceptives with the lowest risk of venous thrombosis had the highest free TFPI and free PS levels. An association was observed between levels of free TFPI and nAPCsr, and between free PS and nAPCsr. The effect of oral contraceptives on TFPI and PS is a possible explanation for the increased risk of venous thrombosis associated with oral contraceptives.
Thrombosis and Haemostasis 02/2013; 109(4). DOI:10.1160/TH12-10-0771 · 4.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Oral contraceptives (OC) containing different types of progestogens induce different sensitivities to activated protein C (APC) measured with the thrombin generation-based APC-resistance test. These differences in APC resistance may be the biological explanation for the differences in thrombotic risk of the various pills. The mechanistic basis of APC resistance observed in OC users is unknown. Our objective was to study the effect of OC on the two main determinants of the APC-resistance test, free protein S and free tissue factor pathway inhibitor (TFPI).
We measured free protein S and free TFPI in 156 users of various types of OC.
Users of desogestrel-containing OC, known to double the risk of thrombosis compared with levonorgestrel-containing OC, had lower free protein S (24 vs. 33 U dL(-1)) and TFPI free antigen (2.9 vs. 3.6 ng mL(-1)) levels than users of OC containing levonorgestrel. Women using cyproterone acetate-containing OC, known to confer a high thrombotic risk, had the lowest free protein S (19 U dL(-1)) and free TPFI antigen (2.5 ng mL(-1)) levels. Users of OC containing drospirenone had lower free protein S (23 U dL(-1)) and TFPI antigen levels (3.2 ng mL(-1)) than users of levonorgestrel-containing OC. Low free protein S and low free TFPI antigen levels were associated with an increased resistance to APC, an established risk factor for thrombosis.
This study observed that the differences in APC resistance induced by OC containing different progestogens can at least in part be explained by different effects of OC on free protein S and TFPI.
Journal of Thrombosis and Haemostasis 03/2008; 6(2):346-51. DOI:10.1111/j.1538-7836.2007.02863.x · 5.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Side effects caused by oral contraceptives discourage compliance with, and continuation of, oral contraceptives. Three approaches have been used to decrease these adverse effects: reduction of steroid dose, development of new steroids, and new formulas and schedules of administration. The third strategy led to the biphasic oral contraceptive pill.
To compare biphasic with monophasic oral contraceptives in terms of efficacy, cycle control, and discontinuation due to side effects. Our a priori hypotheses were: (a) biphasic oral contraceptives are less effective than monophasic oral contraceptives in preventing pregnancy; (b) biphasic oral contraceptives cause more side effects, give poorer cycle control, and have lower continuation rates.
We searched the computerized databases MEDLINE, EMBASE, POPLINE, LILACS and CENTRAL. In addition, we searched the reference lists of all potentially relevant articles and book chapters. We also contacted the authors of relevant studies and pharmaceutical companies in Europe and the USA.
We included randomized controlled trials comparing any biphasic with any monophasic oral contraceptive when used to prevent pregnancy.
We examined the studies found during the various literature searches for possible inclusion and assessed their methodology using Cochrane guidelines. We contacted the authors of all included studies and possibly randomized studies for supplemental information about methodology and outcome. We entered the data into RevMan, and calculated Peto odds ratios for the incidence of intermenstrual bleeding, absence of withdrawal bleeding, and study discontinuation due to intermenstrual bleeding.
Only one trial of limited quality compared a biphasic and monophasic preparation. Percival-Smith 1990 examined 533 user cycles of a biphasic pill (500 microg norethindrone/35 microg ethinyl estradiol for 10 days, followed by 1000 microg norethindrone/35 microg ethinyl estradiol for 11 days; Ortho 10/11) and 481 user cycles of a monophasic contraceptive pill (1500 microg norethindrone acetate/30 microg ethinyl estradiol daily; Loestrin). The study found no significant differences in intermenstrual bleeding, amenorrhea and study discontinuation due to intermenstrual bleeding between the biphasic and monophasic oral contraceptive pills.
Conclusions are limited by the identification of only one trial, the methodological shortcomings of that trial, and the absence of data on accidental pregnancies. However, the trial found no important differences in bleeding patterns between the biphasic and monophasic preparations studied. Since no clear rationale exists for biphasic pills and since extensive evidence is available for monophasic pills, the latter are preferred.
[Show abstract][Hide abstract] ABSTRACT: Side effects caused by oral contraceptives discourage compliance with, and continuation of, oral contraceptives. A suggested disadvantage of biphasic compared to triphasic oral contraceptive pills is an increase in breakthrough bleeding. We conducted this systematic review to examine this potential disadvantage.
To compare biphasic with triphasic oral contraceptives in terms of efficacy, cycle control, and discontinuation due to side effects.
We searched MEDLINE, EMBASE, POPLINE, LILACS and CENTRAL. We searched the reference lists of relevant articles and book chapters. We also contacted the authors of relevant studies and pharmaceutical companies in Europe and the USA.
We included randomized controlled trials comparing any biphasic with any triphasic oral contraceptive when used to prevent pregnancy.
We examined the studies found during the searches for possible inclusion and assessed methodological quality using Cochrane guidelines. We contacted the authors of included studies and of possibly randomized studies for supplemental information about the methods and outcomes. We entered the data into RevMan. We calculated Peto odds ratios for incidence of discontinuation due to medical reasons, intermenstrual bleeding, and absence of withdrawal bleeding.
Only two trials of limited quality met our inclusion criteria. Larranaga 1978 compared two biphasic pills and one triphasic pill, each containing levonorgestrel and ethinyl estradiol. No important differences emerged, and the frequency of discontinuation due to medical problems was similar with all three pills. Percival-Smith 1990 compared a biphasic pill containing norethindrone (Ortho 10/11) with a triphasic pill containing levonorgestrel (Triphasil) and with another triphasic containing norethindrone (Ortho 7/7/7). The biphasic pill had inferior cycle control compared with the levonorgestrel triphasic. The odds ratio of cycles with intermenstrual bleeding was 1.7 (95% CI 1.3 to 2.2) for the biphasic compared with the triphasic levonorgestrel pill. The odds ratio of cycles without withdrawal bleeding was 6.5 (95% CI 3.1 to 13). In contrast, cycle control with the biphasic pill was comparable to that of the triphasic containing the same progestin (norethindrone).
The available evidence is limited and the internal validity of these trials is questionable. Given the high losses to follow up, these reports may even be considered observational. Given that caveat, the biphasic pill containing norethindrone was associated with inferior cycle control compared with the triphasic pill containing levonorgestrel. The choice of progestin may be more important than the phasic regimen in determining bleeding patterns.
[Show abstract][Hide abstract] ABSTRACT: Side effects of birth control pills may keep women from using them as planned. Attempts to decrease side effects led to the three-phase pill in the 1980s. Pills with three phases provide different amounts of hormones over three weeks. One-phase pills have the same amount of hormone for three weeks. Whether three-phase pills lead to fewer pregnancies is unknown. Nor is it known if the pills give better cycle control or fewer side effects. This review looked at whether three-phase pills worked as well as one-phase pills. It also studied whether women had fewer side effects with these pills. We did a computer search for studies of pills with three phases versus pills with one phase. We also wrote to researchers and manufacturers to find other trials. We included randomized trials in any language. The studies had to have at least three treatment cycles. We found 21 trials that looked at three-phase versus one-phase birth control pills. Many studies did not have good methods and the authors did not always report all their methods. The two types of pills did not differ in the numbers of women who got pregnant. Some trials found better bleeding patterns with the three-phase pill. The numbers of women who stopped using the pills were about the same for both types of pills. The evidence was not strong enough to say whether the three-phase pill was better than the one-phase pill for pregnancy prevention, bleeding patterns, or continued use. Therefore, we recommend one-phase pills for women starting to use birth control pills. Large trials of good quality are needed to see if pills with three phases work better than those with one phase.
[Show abstract][Hide abstract] ABSTRACT: It is important for women with diabetes mellitus type 1 and 2 to receive good advice which contraceptive method is best to use. Unplanned pregnancies can lead to serious health issues for both mother and child in women with diabetes. Yet, hormonal contraceptives have been reported to influence glucose and fat metabolism. In this review, both progestogen-only methods (pills and intrauterine device (IUD)) and low-dose combined oral contraceptives appeared to have only minor influences on glucose and fat metabolism. However, only four studies most of limited quality, examining a small number of women were included in this review. Only one of the studies reported on true clinical endpoints i.e. micro- and macrovascular disease. It found no signs or symptoms of thromboembolic incidents or visual disturbances. However this trial was performed over a short period of time. Therefore no definite conclusions can be made based on this review. Future trials analysing glucose and fat metabolism as well as long-term complications for all available contraceptive methods are needed.
[Show abstract][Hide abstract] ABSTRACT: The postcoital test has poor diagnostic and prognostic characteristics. Nevertheless, some physicians believe it can identify scanty or abnormal mucus that might impair fertility. One way to avoid 'hostile' cervical mucus is intrauterine insemination. With this technique, the physician injects sperm directly into the uterine cavity through a small catheter passed through the cervix; the theory is to bypass the "hostile" cervical mucus. Although most gynaecological societies do not endorse use of intrauterine insemination for hostile cervical mucus, some physicians consider it an effective treatment for women with infertility thought due to cervical mucus problems.
The aim of this review was to determine the effectiveness of intrauterine insemination with or without ovarian stimulation in women with cervical hostility who failed to conceive.
We searched Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library Issue 2, 2005, MEDLINE (1966 to June 2005), EMBASE (1980 to June 2005), POPLINE (to June 2005) and LILACS (to June 2005). In addition, we contacted experts and searched the reference list of relevant articles and book chapters.
We included randomized and quasi-randomized controlled trials comparing intrauterine insemination with intercourse timed at the presumed fertile period. Participants were women with cervical hostility who failed to conceive for at least one year.
We assessed the titles and abstracts of 386 publications and two reviewers independently abstracted data on methods and results from five studies identified for inclusion. The main outcome is pregnancy rate per couple.
We did not pool the outcomes of the included five studies in a meta-analysis due to the methodological quality of the trials and variations in the patient characteristics and interventions. Narrative summaries of the outcomes are provided. Each study was too small for a clinically relevant conclusion. None of the studies provided information on important outcomes such as spontaneous abortion, multiple pregnancies, and ovarian hyperstimulation syndrome.
There is no evidence from the published studies that intrauterine insemination is an effective treatment for cervical hostility. Given the poor diagnostic and prognostic properties of the postcoital test and the observation that the test has no benefit on pregnancy rates, intrauterine insemination (with or without ovarian stimulation) is unlikely to be a useful treatment for putative problems identified by postcoital testing.