Blood coagulation and fibrinolytic enzyme studies during cyclic and continuous application of progestational agents

Evaluation of haemostatic function in Nigerian Norplant acceptors after 12 months of use

A total of 55 non-breastfeeding informed volunteers were recruited into a prospective longitudinal study from a family planning clinic between September and December 2002. Blood samples were collected at pre-treatment and at 3, 6 and 12 months follow-up, for packed cell volume, platelet count, prothrombin and activated partial thromboplastin time. Statistical analysis was with paired t-tests. The level of significance was set at 5%. Each subject received a menstrual calendar to chart all bleeding and spotting events. The mean age and weight of acceptors were 32.5 +/- 6.1 years and 63.6 +/- 9.6 kg, respectively. Mean packed cell volume (PCV) was 35.2 +/- 2.9% at pre-insertion. This rose to significant mean +/- SD values of 36.5 +/- 3.1%; p<0.05, 38.5 +/- 2.8%; p<0.0001 and 38.4 +/- 3.6%; p<0.0001 at 3, 6 and 12 months, respectively when compared with the pre-insertion mean value. The mean values of the platelet count showed no significant change at 3 months (238,448 +/- 68,618 mm(3); p>0.9), compared with pre-treatment value (240,545 +/- 96,769 mm(3)). There was a significant reduction in mean concentration at 6 months (p<0.009; 191,364 +/- 55,531 mm(3)) and at 12 months (p<0.003; 202,773 +/- 81,544 mm(3)) follow-up. The prothrombin and the partial thromboplastin time did not show significant change over their pre-insertion mean values of 12.0 +/- 1.1 s and 36.9 +/- 2.9 s, respectively. At 12 months, 79.5% (35) of the users reported an abnormal menstrual pattern, which included 54.5% (24) reduced bleeding pattern, 20.5% (9) increased bleeding and 4.5% (2) of combination of patterns. Only 20.5% (9) had a normal menstrual pattern. The continuation rate was 98%, as one user discontinued because of headaches. Norplant (the registered trademark of the Population Council for levonorgestrel subdermal implants) had an effect on the bleeding pattern - mainly reduced bleeding. The increase packed cell volume is beneficial in preventing anaemia. There was no detrimental effect as a result of the reduced but normal platelet count and users were not predisposed to clotting abnormalities.

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.

Oxidative status and oral contraceptive. Its relevance to platelet abnormalities and cardiovascular risk

Oral contraceptive (OC) use is a risk for thrombogenic events. This paper reviews effects of OC on oxidative status, coagulation, and platelet activity. Complicating effects of cardiovascular risk factors such as smoking, diabetes, hyperpidemia, and hypertension, are discussed. From these data we conclude that: 1. OC use modifies slightly but significantly the oxidative status in women and in animals by decreasing in plasma and blood cells the antioxidant defenses (vitamins and enzymes). 2. The changes in the oxidative status are related to an increase in plasma lipid peroxides apparently responsible for the hyperaggregability and possibly the imbalance in clotting factors associated with the OC-induced prethrombotic state. 3. These effects of OC appear to be increased by a high intake of polyunsaturated fat and counteracted by supplements of vitamin E. 4. The risk factors acting synergistically with OC, have all been shown to increase platelet reactivity. In addition, smoking, diabetes, and, to some extent, dyslipidemia are associated with an increased level of lipid peroxides and concomitant changes in the antioxidant defenses that can be additive to those induced by OC. Thus, free radicals and lipid peroxidation could be the underlying mechanism in the predisposition to thrombosis induced by most risk factors in OC users. 5. Results of epidemiologic and experimental studies in this field will be concordant only when diet and natural antioxidants will be systematically taken into consideration.

A three-year evaluation of hemostatic function in Singaporean Norplant-2 rod acceptors

A longitudinal study of hemostatic function was carried out on 100 Singaporean acceptors using Norplant-2 rods for contraception. The results at the end of three years indicate a possible increased predisposition to thrombosis, as evidenced by significant increases in platelet count and aggregability. The prothrombin time (PT) and activated partial thromboplastin time (APTT) continued to remain shortened at the end of three years of use. There was also a general fall in most of the vitamin K coagulation factors. There is thus still an indication of a possible enhanced potential for hypercoagulation at the end of three years of Norplant-2 rod use.

A three-year evaluation of hemostatic function in Singaporean Norplant acceptors

In a longitudinal study involving 100 Singaporean women, results indicate that the acceptors persist in having a possibly increased predisposition to thrombosis, as evidenced by a significant increase in platelet count and aggregability. Furthermore, the shortened prothrombin time and activated partial thromboplastin time, together with changes in vitamin K factors, still indicate the possible enhanced potential for hypercoagulation.

Effect of levonorgestrel contraceptive implants, Norplant, on blood coagulation

A longitudinal study of coagulation parameters was carried out on 47 women using the levonorgestrel subdermal implants, NORPLANT. The study comprised measurement of platelet count, prothrombin time, thrombin time, partial thromboplastin time with kaolin, clotting factors I, II, V and VI through XIII, plasminogen, antithrombin III (AT III), alpha 1 antitrypsin, alpha 2 macroglobulin and fibrinogen degradation products. The tests were done at admission and after one, three and six months of NORPLANT use. Parallel and similar studies were done on two groups of oral contraceptive users; the first group used a pill containing 1 mg norethisterone and 50 micrograms mestranol, and the second a pill consisting of 150 micrograms levonorgestrel and 30 micrograms ethinylestradiol. Results from this ongoing study have indicated that women using NORPLANT implants evidenced lack of effects on most of the parameters tested except for factor VII activity which was increased and AT III concentration which was decreased after six months of use. The combined pill users evidenced marked changes in the platelet count, the screening tests and in most of the coagulation-promoting factors; the changes were apparent after three months of use and became more pronounced after six months. The results demonstrate, with marked contrast, that the implants had less pronounced effects on the blood coagulation system than did the combined pills used in this study.

Serum phospholipid fractionation after the use of long-acting progestational contraceptives

The effect of the two long-acting progestational contraceptive injection, depot-medroxyprogesterone acetate (DMPA) and norethisterone onenathate (NET-OEN), on blood phospholipid fractions were studied in eighteen women. The post-injection results showed a significant increase in total serum phospholipids, serum lecithin and serum cephalins. Serum lysolecithin was significantly decreased while serum sphingomyelin showed no significant change. The mechanisms responsible for these phospholipid changes remain somewhat unclear. However deranged liver function may share in its explanation.

Response of plasma fibrinogen and plasminogen to hormone treatment and the relation of pretreatment values to mortality in patients with prostatic cancer

Fibrinogen and plasminogen were measured in plasma samples from prostatic cancer patients before and after 3 months of treatment with either Premarin, Provera, Provera and diethylstilbestrol, one of three doses of diethylstilbestrol, or placebo. Plasminogen levels generally were increased significantly with the estrogens but were unchanged following placebo or Provera treatment. Pretreatment plasminogen levels in Study 3 were significantly lower (p less than .001) than in Study 2. Plasminogen pretreatment levels were significantly correlated with age, hemoglobin, body weight, and blood pressure. Fibrinogen pretreatment levels were significantly elevated above normal. They were not significantly with age, hemoglobin, body weight, or blood pressure. Fibrinogen levels generally were significantly decreased by the estrogens. Comparisons of means of pretreatment fibrinogen and plasminogen levels from patients dying during the first year of the study with the mean pretreatment levels of the patient group alive after 1 year on study yielded no significant differences. Death rates were calculated by pretreatment plasminogen or fibrinogen for all treatments of all Stage III and Stage IV patients combined for Study 2 and Study 3 separately. Such rates were calculated for all causes combined and for deaths from prostatic cancer or cardiovascular disease separately. The levels of plasminogen were significnatly negatively correlated with death rate from all causes combined and with cardiovascular disease considered separately, but not with death from prostatic cancer. The levels of fibrinogen were signigicantly positively correlated with death rates from all cuses and nearly significantly with prostatic cancer, but not cardiovascular disease. Elvated pretreatment fibrinogen levels were associated with an increased proportion of deaths at 1 year from all causes and from cancer of the prostate.

A study of blood coagulation parameters

The object of this study was to determine the presence or absence of abnormalities in a variety of blood coagulation parameters in women on contraceptive medication. A prospective double-blind study involving a control group with a total study enrollment of 211 women during a 29 month period was established. Although research has not proved that changes in coagulation parameters will cause abnormal clotting in normal patients, a pattern appears to be developing involving antithrombin III determinations. Corresponding patterns do not appear to be developing in the other blood coagulation parameters.