Effects of three types of combined O.C. pills on blood coagulation, fibrinolysis and platelet function

The influence of sex hormones on coagulation and inflammation in the trauma patient

Recent clinical studies have shown a sex dimorphism of morbidity and mortality due to shock, trauma, and sepsis, with females tolerating these insults better than males. Experimental animal studies have suggested that sex hormones have a pivotal role in this dimorphism. In the present investigation, a prospective cohort study at a university level-1 trauma center was conducted to evaluate the association between sex hormones and alterations in coagulation and inflammation. Patients with an admission to the intensive care unit, injury severity score (ISS) greater than 4, and obtainable consent were included in the study. In addition to routine clinical laboratories and patient outcomes, plasma TNF-[alpha], IL-6, IL-8, estradiol, progesterone, and testosterone were measured. Sixty-two patients (71% men, 29% women) met criteria for entry. Mean age was 42 +/- 17 years, and mean ISS was 23 +/- 13, with no statistical difference in age or ISS between sexes. Estradiol levels were positively correlated with ISS (P < 0.05) and negatively correlated with TNF-[alpha] (P < 0.01). Initial estradiol levels were higher in patients who developed an infection (P < 0.05). Testosterone was negatively correlated with age (P < 0.01) and was higher in patients who developed acute respiratory distress syndrome (P < 0.05) and in patients who did not survive (P < 0.05). The estradiol-to-progesterone ratio (E2-Pr) was higher in the survivors (P < 0.05). The E2-Pr had positive correlations with fibrinogen levels, rate of fibrin deposition and cross-linking, and overall clot strength (P < 0.05). Estradiol-to-progesterone ratio was negatively correlated with partial thromboplastin times (P < 0.01). In men, the E2-Pr was also negatively correlated with the time to onset of clot formation (P = 0.03). Sex hormone levels (or their ratios) were not correlated to platelet count or international normalized ratios. These findings provide evidence that sex hormone levels in the early posttraumatic period are significantly associated with alterations in the hemostatic and inflammatory response to trauma.

Effect of four oral contraceptives on hemostatic parameters

This is the first double-blind, controlled, randomized study comparing the effect of different estrogen components in oral contraceptives (OCs) on hemostasis variables. Four groups of 25 women each were treated for six cycles with monophasic combinations containing 21 tablets with either 30 microg ethinylestradiol (EE) + 2 mg dienogest (DNG) (30EE/DNG), 20 microg EE + 2 mg DNG (20EE/DNG), 10 microg EE + 2 mg estradiol valerate (EV) + 2 mg DNG (EE/EV/DNG) or 20 microg EE + 100 microg levonorgestrel (LNG) (EE/LNG). Blood samples were taken on Days 21-26 of the control cycle and on Days 18-21 of the first, third and sixth treatment cycle. Treatment with all four OCs caused an increase in levels of fibrinogen, prothrombin fragment 1+2, D-dimer, plasminogen, plasmin-antiplasmin complex and an increase in protein C activity, a decrease in antithrombin activity, tissue-plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI), and a slight decrease in the sensitivity to activated protein C, but no significant change in that of the thrombin-antithrombin complex. In users of the DNG-containing OCs, the reduction in total and free protein S, and in t-PA and PAI was dependent on the EE dose, while factor VII activity was elevated, but not significantly different from EE/LNG. The results are in agreement with those of previous studies. The effects of EE/EV/DNG on total and free protein S and on t-PA and PAI were lower than those of 20EE/DNG, suggesting that the impact of 2 mg EV on several hemostasis variables is less than that of 10 microg EE. The results show an antagonistic effect of LNG on the EE-induced rise of factor VII activity and fragment 1+2 and on the EE-dependent reduction of total and free protein S.

Hemostatic effects of third- and second-generation oral contraceptives: absence of a causal mechanism for a difference in risk of venous thromboembolism

Some observational studies have found a difference in the risk of nonfatal venous thromboembolism (VTE) with low-dose, oral contraceptives (OCs) containing desogestrel (DSG) or gestodene (GSD) and those containing levonorgestrel (LNG). However, this does not agree with current pathophysiological concepts. This review compares all 17 comparative studies on the hemostatic effects of DSG/GSD- and LNG- or norgestimate (NGM)-containing OCs, and comments on two recent cross-sectional studies on the effects of third- and second-generation OCs on activated protein C (APC) sensitivity. In the comparative studies, the only difference in hemostatic parameters between DSG/GSD- and LNG- or NGM-containing OC users was a tendency towards higher factor VII (FVII) levels with DSG/GSD OCs. Differential effects on APC sensitivity were observed with the endogenous thrombin generation potential (ETP) assay, but not with the classical APC resistance test. FVII is not a risk marker for VTE, but is affected by dietary fat, estrogens and androgens and may interfere with the ETP assay. As no differences in established VTE risk markers were observed, there is no plausible reason for a differential risk of VTE with DSG/GSD- and LNG-containing OCs. In fact, the lack of differences with regard to established risk markers of VTE gives further support to the findings of the most recent epidemiological studies, which have not found any difference in the risk of VTE between third- and second-generation OCs.

Pharmacodynamics of oestrogens and progestogens

The ovaries cyclically secrete estradiol and progesterone. Cyclic ovarian estradiol secretion is associated with a bone-saving and vascular protection effect. Endogenous progesterone does not modify the vasodilator effect of oestrogens. At physiological concentrations, the natural sex steroids have low antigonadotropic effects. More potent synthetic derivatives with more antigonadotropic effects were synthesized in the 1950s. After the menopause, there is no longer any need to use hormonal steroids as antigonadotropics. In addition, vascular contraindications are more common in an older population. Contraceptive steroids (particularly ethinyl estradiol) are therefore rarely used. The oestrogen that is most widely prescribed for post-menopausal replacement is a complex formulation of conjugated oestrogens of equine origin that is administered orally in a single daily dose. Improvements in hormone replacement therapy may result from the use of parenteral estradiol (providing sufficient doses are reached) and of a progestogen chemically more similar to progesterone.

An open label, randomized study to evaluate the effects of seven monophasic oral contraceptive regimens on hemostatic variables. Outline of the protocol. Oral Contraceptive and Hemostasis Study Group

Complementary to the epidemiological knowledge on the association between oral contraceptive use and the occurrence of venous thromboembolism, a study was designed to obtain more conclusive data regarding the effect of estrogen dose and progestogen type of oral contraceptives on risk markers for the occurrence of venous thromboembolism. The protocol for this multicenter, randomized, open label, parallel group, comparative study is outlined in the present article. A total of 730 healthy, nonsmoking, mulliparous women were treated for six cycles with one of the seven monophasic oral contraceptives tested in this study. The effects of progestogen type (desogestrel, gestodene, levonorgestrel, and norgestimate) and the effects of ethinyl estradiol dose (50, 30, and 20 micrograms) on various hemostatic variables was assessed, including the key components of the anticoagulant and fibrinolytic system, as well as the coagulation system. The primary outcome variables in the study were prothrombin fragment 1 + 2 and D-dimer.

Effects on hemostasis after two-year use of low dose combined oral contraceptives with gestodene or levonorgestrel

We studied 67 healthy women who were randomly allocated to receive third generation gestodene (Gynera) or second generation levonorgestrel (Microgynon 30) combination of low-dose estrogen oral contraceptives (OCs) for their hemostatic effects over 2 years. Hemostatic changes were apparent within 3 months of OC use. Hematocrit (Hct) was not affected, but hemoglobin (Hb) concentration decreased by 18 months. Shortened prothrombin time (PT) and activated plasma thromboplastin time (APTT) were associated with elevated fibrinogen within the 12-month use of both OCs. Factor VII was reduced only in Micro 30 during the 18 months of use. Enhanced thrombin-antithrombin (TAT)-complex level was seen at 18 months of Gynera use. Prothrombin fragment1+2 (F1+2) rise was seen at 3 months with Micro 30. Reduced antithrombin III (ATIII) activity was seen at 18 months with Gynera and at 24 months with Micro 30. Increased protein C activity was seen at 3 months and reduced protein S occurred at 18 months of Gynera use. Tissue plasminogen activator (t-PA) activity was enhanced for 6 months in both OCs with raised D-dimer levels for 12 months with Gynera and 6 months with Micro 30. Decreased t-PA antigen was seen at 18 months and decreased urokinaselike plasminogen activator (u-PA) antigen occurred throughout the 24 months of both OCs use. Enhanced u-PA activity was only seen in Gynera users. Elevated plasminogen levels were apparent throughout both OCs use. PAI-1 levels were significantly decreased with Micro 30. With Gynera, the decreased PAI-1 activity was seen only at 18 months and PAI-1 antigen at 12 months. No change in platelets and von Willebrand factor (vWF) were seen in long-term OC use except that beta-thromboglobulin (beta-TG) showed decreased trends reaching statistical significance by 18 and 24 months of Micro 30 use and by 24 months of Gynera use. A further significant decrease in beta-TG, u-PA antigen, ATIII, and protein S levels were seen 3 months after pill stoppage compared with pretreatment levels. Activated protein C resistance (APCR) was negative in all subjects before and during OC use. The study indicated dynamic balance between coagulation and fibrinolysis with no endothelial activation. However, because some hemostatic markers showed wide fluctuations during OC use, a longer term study is warranted to investigate any adverse hemostatic changes that might enhance the risks of venous thromboembolism in Asian subjects known to be less prone to thrombosis.

Effects on hemostatic variables of desogestrel- and gestodene-containing oral contraceptives in comparison with levonorgestrel-containing oral contraceptives: a review

In some studies third-generation oral contraceptives have been reported to be associated with a higher risk of venous thromboembolism than are second-generation oral contraceptives, whereas recent, more refined studies have not confirmed this. The reasons for the alleged differences are under discussion, and differential effects on hemostasis have been proposed. Eighteen studies comparing second- and third-generation oral contraceptives with respect to their effects on hemostasis were analyzed. Significant changes from baseline were reported for many variables with both second- and third-generation oral contraceptives without significant between-group differences. Also, in a combined analysis of nonsignificant changes, no consistent pattern of change emerged for any marker, with the exception of higher factor VII levels associated with third-generation oral contraceptives. However, factor VII is not related to venous thromboembolism risk. In addition, 1 cross-sectional study with an unvalidated assay reported a higher ratio of activated protein C sensitivity with third-generation oral contraceptives. Only 2 components of the hemostatic system (factor VII and activated protein C sensitivity ratio) emerged as potentially differentially affected by second- and third-generation oral contraceptives; the association with venous thromboembolism risk is questionable in the former case and unknown in the latter.

Effects of oral contraceptives on coagulation factors in African women

Despite overwhelming evidence that the use of oral contraceptive pills (OCP) may lead to thrombotic episodes, no studies have been performed to investigate the effect of OCP on the coagulation profile in African women. We assessed the levels of fibrinogen, factors VIIc, and VIIIc as well as the fibrinolytic activity in 100 African women on OCP. Fibrinogen levels were significantly increased (p<0.001) and factors VIIc, VIIIc, and fibrinolytic activity significantly decreased (p<0.001) when compared with those of healthy women not on OCP. We conclude that the combination of hyperfibrinogenaemia and decreased fibrinolytic activity combined with a decrease in factor VIIc and VIIIc levels reflects a hemostatic imbalance in African women on OCP that needs to be investigated.

Haemostatic changes and the oral contraceptive pill

Oral contraceptives have been linked to an increased incidence of thrombovascular disease. This may be mediated by their effects on the haemostatic system. An increase in the activity of coagulation Factors VII, X and fibrinogen occur with pill usage. Increased Factor VII levels are dependent on both the oestrogen and progestogen component of the oral contraceptive. A reduction in antithrombin III levels has also been observed in some but not all studies. Increased fibrinolysis has also been shown in oral contraceptive users which should balance the changes in the coagulation pathway. The increase in fibrinolytic potential is thought to be due to a decrease in the levels of plasminogen activator inhibitor I combined with an increase in the levels of plasminogen; tissue plasminogen activator antigen is decreased in most studies. The increased levels of endpoints of coagulation and fibrinolysis in pill users indicate that enhanced activity of both systems is occurring in vivo. The increased coagulation activity appears to be balanced by the rise in fibrinolytic activity, so preserving haemostatic balance. Enhanced platelet activity has also been shown in women taking oral contraceptives. Thrombus formation can result, however, when local vascular wall damage exists, or when other risk factors for thrombo-embolism, such as older age and smoking, coexist and create a local activation resulting in a thrombus. In these situations, the small differences in levels of coagulation factors in women taking different oral contraceptive formulations may be important. Pills containing the lowest doses of oestrogen (20 micrograms ethinyloestradiol) have shown the least changes in haemostatic factors. The progestogen component of the pill modifies the effect of oestrogen on the haemostatic system.

Double-blind, randomized, placebo controlled study on the effects of the monophasic oral contraceptive containing 30 micrograms ethinyl estradiol and 2.00 mg dienogest on the hemostatic system

Forty healthy female volunteers aged between 19 and 35 years (27.3 +/- 4.1 years) with normal menstrual cycles were included in a double-blind, randomized, placebo-controlled study to investigate the influence on the hemostatic system of an oral contraceptive containing 30 micrograms ethinyl estradiol in combination with 2.00 mg dienogest, which is a 19-norprogestin without a 17 alpha-ethinyl group. At baseline and during one treatment cycle, 12 hemostatic parameters were measured on cycle days 7, 14, and 21. The hemostatic parameters were categorized as either procoagulatory, anticoagulatory and profibrinolytic, or antifibrinolytic and indicative of fibrin turnover. Differences between placebo and 30 micrograms ethinyl estradiol and 2.00 mg dienogest of plasma levels of hemostatic parameters on cycle days 21 of the precycle and treatment cycle were chosen as target variables. Prothrombin fragment 1 + 2 (F 1 + 2) was chosen as the main target variable. Equivalence of F 1 + 2 between placebo and active treatment was noted. Among the procoagulatory factors, only factor VII activity was found to be increased over placebo in the active treatment group, but decreased in the placebo group. Protein C activity increased during the treatment with 30 micrograms ethinyl estradiol and 2.00 mg dienogest, and was higher than that of the placebo group in which this parameter decreased during the treatment cycle. There was a corresponding increase in fibrinolytic activity being reflected by higher plasminogen levels in the active treatment group in comparison with placebo. An increase was noted for the fibrinolytic parameter D-dimer. Apart from isolated measurements, the parameters remained in their respective normal ranges. The data combine to suggest that 30 micrograms ethinyl estradiol and 2.00 mg dienogest has a balanced effect on the hemostatic system stimulating both procoagulatory and fibrinolytic activity.

Inhibition of ovulation by an oral contraceptive containing 100 micrograms levonorgestrel in combination with 20 micrograms ethinylestradiol

Twenty-four healthy female volunteers with normal ovulatory cycles, aged between 20 and 34 years (27.5 +/- 4.3), were included in a single-center, non-comparative study to investigate the effect on inhibition of ovulation of an oral contraceptive containing 20 micrograms ethinylestradiol in combination with 100 micrograms levonorgestrel. At baseline, during three treatment cycles and post-treatment, ultrasonography was used to examine the ovaries, to measure follicular size, and to measure the thickness of the endometrium. Serum levels of LH, FSH, estradiol, progesterone, total testosterone, free testosterone, SHBG, and CBG were also measured. Compared with treatment cycle 1, an increase in residual ovarian activity (follicle grades 4-5) was observed in cycles 2 and 3. Mean levels of LH, FSH, 17 beta-estradiol and progesterone remained suppressed during treatment. No escape ovulation was observed during the treatment phase of the study and there were no pregnancies. Ovulation was noted to return rapidly in the posttreatment cycle. Subjective and objective tolerance of the present regimen was noted to be good. Results indicate that the monophasic oral contraceptive containing 100 micrograms levonorgestrel combined with 20 micrograms ethinylestradiol effectively inhibits ovulation, providing adequate suppression of ovarian activity.

The role of triphasic levonorgestrel in oral contraception: a review of metabolic and hemostatic effects

Epidemiological studies suggesting a possible association between the use of combined oral contraceptives and an increased risk of cardiovascular disease have led to extensive investigations into the effect of oral contraceptives on lipid and carbohydrate metabolism, and on hemostasis. Since this association was originally suggested, the steroid dose in oral contraceptives has been significantly reduced and new progestogens have been developed. Also, triphasic formulations have been introduced which offer a well-balanced estrogen/progestogen ratio, allowing a further reduction in the progestogen dose per cycle, and thus helping to minimize unwanted metabolic and hemostatic effects. The metabolic interactions of triphasic levonorgestrel, the first triphasic formulation to be introduced, have received particular attention. Lipid metabolism appears to be largely unaffected by triphasic levonorgestrel, most studies reporting no significant change in high- (HDL-C) or low-density lipoprotein-cholesterol (LDL-C) levels. Several studies have reported a decrease in the lipoprotein subfraction HDL2-C levels, but in most cases measurements of the LDL-C/HDL-C and apolipoprotein A-1/B ratios reveal no clinically significant effects. Concerning lipids, most studies suggest that triphasic levonorgestrel has less metabolic impact than the monophasic formulation. In common with all currently available oral contraceptives, triphasic levonorgestrel appears to have some effect on carbohydrate metabolism. The study results vary, however; some investigators have found an impairment of glucose tolerance, whereas others have not detected any significant effect. Compared with lipid and carbohydrate metabolism, fewer studies have investigated the effect of triphasic levonorgestrel on hemostasis. In common with all estrogen-containing oral contraceptives, levonorgestrel appears to stimulate some procoagulant activity, elevating the levels of factors VII and X, and fibrinogen. However, the effect of triphasic levonorgestrel appears to be balanced, with most studies reporting a corresponding increase in anti-coagulant-fibrinolytic activity. Although most of the studies reviewed here reported some statistically significant metabolic interactions, many authors comment that the changes are probably not clinically relevant in terms of an altered risk of cardiovascular disease. The true risk of vascular disease associated with modern low-dose oral contraceptives remains to be confirmed when sufficient epidemiological data eventually become available.

Effects of progestogens on haemostasis

Epidemiological data suggested an involvement of the progestogen component in the pathomechanism of venous and arterial diseases during intake of oral contraceptives. The influence of progestogens on haemostasis parameters depend on type and dose of the progestogen, the presence of an estrogen, the route of application, and the duration of use. Treatment of women with progestogen-only preparations caused only minor effects on coagulation and fibrinolysis. Similarly, during hormone replacement therapy with natural estrogens, the additional application of progestogens induced no unfavourable changes on haemostasis. In contrast, the use of ovulation inhibitors resulted in an acceleration of coagulation and fibrinolysis. This is primarily induced by the marked action of ethinylestradiol on hepatic and vascular function. Progestogens with androgenic properties may counteract the estrogen-induced changes in the hepatic synthesis of platelet aggregation and readiness for coagulation. Estrogen and progesterone receptors are localized in endothelial and smooth muscle cells of the vessel wall, but there are differences in the response of veins and arteries to sex steroids. Estrogens and progestogens may influence collagen and elastin synthesis, and the release of vasoactive compounds and of factors controlling fibrinolysis from endothelium. In veins, progestogens may increase distensibility and capacitance resulting in a decreased blood flow. In predisposed women, this may lead to venous stasis and thrombosis. In arteries, progestogens may act as vasoconstrictors, and may enhance vasospasms at sites of injured endothelium which finally may lead to ischemic diseases.

The effects of two phasic oral contraceptives on hemostasis and platelet function

OBJECTIVE

To compare the effects on hemostatic parameters of a combiphasic oral contraceptive containing desogestrel and ethinyl estradiol (DSG/EE) and a triphasic oral contraceptive containing levonorgestrel and ethinyl estradiol (LNG/EE).

METHODS

In an open-label, randomized, group-comparative study in 10 healthy volunteers per treatment group, the effects on parameters of coagulation, anticoagulation, fibrinolysis, antifibrinolysis and platelet function were determined at baseline, after three treatment cycles, and after a post-treatment cycle. Changes from baseline were analyzed using a paired t-test, whereas between-group differences were analyzed by means of an analysis of co-variance.

RESULTS

Both OC preparations induced modest changes of some coagulation, anticoagulation, fibrinolysis and antifibrinolysis parameters, although all mean values remained within the normal range. No significant effects were observed with either OC with respect to platelet function. Statistically significant differences between the two preparations could occasionally e observed: the concentrations of antithrombin II (AT-III) and Factor VII were higher with the DSG/EE preparation than with LNG/EE preparation at the end of treatment and AT-III activity, AT-III concentration, Factor X concentration, and plasminogen activity were higher with DSG/EE than with LNG/EE in the post-treatment cycle.

CONCLUSIONS

Combiphasic DSG/EE and triphasic LNG/EE, both OCs with a comparable amount of EE per cycle, had no clinically significant effect on the overall hemostatic balance.

Twelve years of clinical experience with an oral contraceptive containing 30 micrograms ethinyloestradiol and 150 micrograms desogestrel

The clinical experience with a combined oral contraceptive (COC) containing 150 micrograms desogestrel and 30 micrograms ethinylestradiol is reviewed. Fourteen clinical trials have been reported involving over 44,000 women for more than 190,000 cycles. None of the 17 pregnancies which occurred (overall Pearl Index 0.12) were due to method failure. The incidences of breakthrough bleeding and spotting after 6 treatment cycles varied from 0.1-6.0% and 2.8-11% of subjects, respectively, and at this time they were not significantly different from pretreatment in most trials. About 90% of subjects maintained regular cycles. The incidence of subjective side effects (approximately 5% for headache, 4% for breast tenderness, 2% for nausea) was low. No significant changes occurred in body weight or blood pressure. In all trials, the COC was well accepted and the rates of discontinuation were similar to those in other COC trials. Pharmacodynamic effects have been widely investigated. There were no significant changes in glucose metabolism or in haematological factors except for possibly minor increases in factors VII and X, fibrinogen and plasminogen. Over thirty studies of the effect of the COC on lipid metabolism have been published; significant increases occur in serum triglycerides, HDL-C and apoprotein A1. SHBG concentrations increase 2-3 fold with a consequent decrease in the levels of free testosterone. This effect can be particularly important therapeutically in women with hyperandrogenic skin disorders and 14 trials in women with these disorders have demonstrated significant clinical improvement with the COC. The findings from the various trials show the COC to be effective and acceptable with no adverse metabolic effects.

Coagulation and anticoagulation effects of contraceptive steroids

Epidemiologic data support the notion that first-generation high-dose oral contraceptives (containing > 80 micrograms of estrogen) increased the incidence of thromboembolic events. The quantitative interpretation of these data is difficult because results were often confounded by life-style factors and inadequate diagnostic procedures. With the introduction of modern low-dose combination oral contraceptives, the incidence of thromboembolic events decreased markedly. Although all combined oral contraceptives induce statistically significant changes in hemostatic factors, these changes are generally within normal ranges, and their clinical significance is questionable. Overall, increased activity in hemostatic mechanisms appears to remain in balance. Progestin-only formulations seem to affect hemostatic parameters to a much lesser degree, and their use has not led to an increased risk of thrombosis. Interindividual variations in pharmacokinetics and pharmacodynamics of contraceptive steroids are great and could tentatively explain why certain persons may be at an increased risk of thrombosis. Although most studies have looked at steady-state conditions during contraceptive steroid intake, it would seem prudent to investigate further the hemostatic system during a non-steady-state condition, such as that occurring during the first few days of the pill-free interval.

New progestogens in oral contraception

The major developments in combined oral contraceptives (COCs) have been a reduction in the total dose of both the oestrogen and progestogen administered per cycle and the introduction of new progestogens which are claimed to be more 'selective' than the older ones. This review examines in detail the clinical efficacy of the new COCs, where possible in comparison with those containing levonorgestrel or norethisterone, and their pharmacological effect on carbohydrate and lipid metabolism, haematological factors, pituitary-ovarian function and serum protein and androgen concentrations. Based mainly on the pharmacological evidence, the newer COCs are an improvement over the older low-dose formulations and are clearly preferable to the high-dose ones. However, the older low-dose COCs, despite many years of use, have not resulted in a high incidence of adverse effects. The increasing use of the new COCs, as evidenced by their increasing market share throughout Europe, does indicate that they have been well accepted in clinical practice.

Evaluation of hemostatic function following Norplant-2 rods removal

Women using the Norplant-2 rod system in Singapore have been shown to have a change in their hemostatic function. There is a decrease in vitamin K dependent factors II, VII and a tendency toward lowered fibrinolytic activity after use of Norplant-2 rods. There was also an increase in platelet number and accelerated-platelet aggregation. These changes are similar to those seen with the Norplant six-capsule system and it would appear that both systems do not activate the coagulation system or enhance a state of hypercoagulation. On removal of the Norplant-2 rods at the end of 5 years, the significant changes seen in hemoglobin function observed with Norplant-2 rod use remained.

Changes in blood levels of proteinase inhibitors, pregnancy zone protein, steroid carriers and complement factors induced by oral contraceptives

Three low-dose oral contraceptives Trinordiol, Gynatrol, and Marvelon, containing ethinylestradiol (EE) in combination with triphasic levonorgestrel (LNg), monophasic levonorgestrel, and monophasic desogestrel (DGS), respectively, were given to 65 healthy women, n = 21-22 in each group. Blood levels of antithrombin III (AT III), alpha 2-macroglobulin (alpha 2M) alpha 1-antitrypsin (alpha 1at), complement factors (factor B, C3, C4), pregnancy zone protein (PZP), corticosteroid binding globulin (CBG), sex hormone binding globulin (SHBG) and albumin were measured before treatment and during the first and third treatment cycles. AT III levels decreased and alpha 1at levels increased in all three groups during treatment. alpha 2M increased during cycle 3 in the Trinordiol and Gynatrol groups. CBG, PZP and SHBG levels increased in all 3 groups, the CBG and PZP increase being higher in the Marvelon group than in the Gynatrol group. Increases in SHBG levels were found in the order Marvelon > Trinordiol > Gynatrol. Plasma levels of complement factors B, C3 and C4 remained unchanged. It is concluded that the increase in alpha 1at partly compensates for the fall in AT III, that the rise in PZP presumably enhances fibrinolysis, and that LNg has higher anti-estrogenicity and androgenicity than DSG.

The effects on hemostasis of oral contraceptives containing desogestrel

Epidemiologic research has shown that current low-dose estrogen oral contraceptives are associated with a low risk of vascular events (e.g., myocardial infarction, stroke, and venous thrombosis or thromboembolism). Yet questions still persist about the effects of low-dose oral contraceptives on the cardiovascular system. Changes in the coagulation system have been linked primarily to the estrogen component; however, it has been proposed that the progestin may have an influence on the fibrinolytic system. Desogestrel, a new gonane progestin, has been commercially available in Europe since 1981. It has been widely shown to produce minimal changes of the coagulation and fibrinolytic systems, and it has not been associated with an increased risk of thromboembolic disorders.

Evaluation of hemostatic function following Norplant implant removal

Norplant implant use in Singapore showed a decrease in vitamin K-dependent Factors II, V, VII and reduction in fibrinolytic activity at the end of 5 years of use. Increased platelet numbers and accelerated platelet aggregation were also found throughout the 5 years of Norplant use. It thus appears that unlike the combined pill, prolonged Norplant use does not activate the coagulation system and does not enhance a state of hypercoagulation. On removal of the Norplant implants at the end of 5 years, the significant changes seen in hemostatic function observed with Norplant use remained.

Effects of monophasic low-dose oral contraceptives on fibrin formation and resolution in young women

OBJECTIVE

The purpose of this study was to examine key variables in the regulation of coagulation and fibrinolysis during intake of low-dose oral contraceptives containing newly developed progestogens.

STUDY DESIGN

Thirty-four healthy young women were allocated to 12 consecutive cycles of treatment with monophasic combinations of 20 micrograms ethinyl estradiol and 150 micrograms desogestrel (n = 15) or 30 micrograms ethinyl estradiol and 75 micrograms gestodene (n = 19). Nonparametric analysis of variance was used for statistical evaluation.

RESULTS

In both groups plasma levels of fibrinogen and Factor VIIc increased, and the capacity of coagulation inhibition was affected by increased protein C and decreased protein S levels. Increased fibrinolytic capacity was indicated by elevated activity and reduced antigen levels of tissue plasminogen activator and by reduced activity and concentration of plasminogen activator inhibitor. Thrombin-antithrombin III complexes and fibrin degradation products were unchanged, signifying no effect of hormonal intake on the degree of activation of the coagulation system or the efficacy of fibrinolysis.

CONCLUSION

The overall dynamic balance between generation and resolution of fibrin was maintained during treatment with both hormonal compounds. Our findings suggest that the risk of thrombosis in normal women should not be increased.

Effect of Norplant-2 rods on haemostatic function

A longitudinal study on one-hundred Singaporean women using Norplant-2 rod implant for contraception and their effects on the haemostatic function was carried out. There was a decrease in vitamin K-dependent Factors II, VII and a tendency towards lowered fibrinolytic activity after prolong use of Norplant-2 rods. The results indicate that the Norplant-2 rod implant system does not contribute towards hypercoagulable state but increased platelets and accelerated platelet aggregation observed will require further study to ascertain whether there is a concomitant increase in platelet activation.

Effect of long-term use of Norplant implants on haemostatic function

This study describes the effects of Norplant on haemostatic function after 5 years of use in 97 women. There was a decrease in vitamin-K dependent Factors II, V, VII and reduction in fibrinolytic activity at 2 and 4 years of use. Increased platelet numbers and accelerated platelet aggregation were found throughout the 5 years of Norplant use, whilst raised alpha 2-Macroglobulin (a2-M) and antithrombin III (ATIII) antigen level were observed for up to 4 years of use. Prolonged Norplant use does not appear to activate the coagulation system and does not enhance a state of hypercoagulation.

The clinical relevance of oral contraceptive pill-induced plasma lipid changes: facts and fiction

The changes in plasma lipids induced by the use of oral contraceptive pills have been shown in several studies to remain within normal physiologic limits. These changes are then probably without any clinical relevance because there is no evidence in the huge volume of oral contraceptive and cardiovascular literature that the use of oral contraceptives promotes or retards the development of atherosclerotic disease. What may appear to be favorable changes in the lipid profile attributed to oral contraceptive use may actually be associated with unfavorable changes in other parameters, such as the balance of clotting and fibrinolytic factors. A well-balanced, low-dose oral contraceptive formulation should alter any of the cardiovascular risk indicators as little as possible in either a supposedly positive or negative direction.