Effect of estrogens on postpartum hypercoagulability and antithrombin 3 activity

Female platelets have distinct functional activity compared with male platelets: Implications in transfusion practice and treatment of trauma-induced coagulopathy

BACKGROUND

Females are hypercoagulable and have survival benefit in trauma-induced coagulopathy (TIC). The mechanism for this sex-specific hypercoagulability is unknown. Platelets and platelet function are central in providing hemostatic potential and are the largest contributor to clot strength. Ligands (adenosine diphosphate [ADP] and platelet-activating factor [PAF]) bind distinct platelet receptors to potentiate activation and aggregation. We hypothesize that female platelets have a differential response to ADP and PAF, resulting in greater aggregation and activation compared to males, and that estradiol pretreatment of male or female platelets enhances this activity.

METHODS

Platelets were collected from healthy volunteers: premenopausal/postmenopausal females (≤54 years, >54 years) and similarly aged males. Platelet aggregometry and flow cytometry (fibrinogen binding capacity) were examined. After treatment with ADP or PAF, platelet aggregation was assessed with Chronolog and activation assessed by CD41 receptor surface expression using flow cytometry. Aggregation and activation were again assessed after platelet pretreatment with estradiol.

RESULTS

Healthy volunteers included 12 premenopausal and 13 postmenopausal females and 18 similarly aged males. Female platelets (combined premenopausal and postmenopausal) had increased aggregation with ADP stimulation, as compared to male platelets. Male and female platelets had differential fibrinogen receptor expression, with female platelets (combined premenopausal and postmenopausal) demonstrating robust activation with ADP versus male platelets with PAF. In the presence of estradiol incubation, male platelets' activation with PAF approximated that of females (combined premenopausal and postmenopausal) and activation with PAF was enhanced in both male and female platelets.

CONCLUSION

Male and female platelets have differential response to stimuli, suggesting sex-dependent signaling and cellular activation. Female platelets have both increased aggregation and activation potential, and estradiol pretreatment feminizes male platelets to approximate female platelet activation with PAF. These findings offer potential explanation for sex-based differences in hemostatic potential in TIC and question whether donor sex of transfused platelets should be considered in resuscitation. Estradiol may also serve as a novel therapeutic adjunct in TIC.

Global hemostasis in healthy bitches during pregnancy and at different estrous cycle stages: Evaluation of routine hemostatic tests and thromboelastometry

This study assessed the global hemostasis (including prothrombin time [PT], activated partial thromboplastin time [aPTT], antithrombin activity [ATA], fibrinogen and d-Dimer concentrations, platelet count, plateletcrit and thromboelastometry) in healthy pregnant bitches, comparing the results with those of healthy bitches at different estrous cycle stages, and assessed whether hemostatic changes during pregnancy are associated with serum progesterone concentration or the presence of fetuses in utero. The results show that pregnant bitches have higher fibrinogen concentration, platelet count and platelatecrit, and that fibrin and global clot formations occur faster than in non-pregnant bitches at different estrous cycle stages. Additionally, clot strength was higher in pregnant bitches than in non-pregnant ones. There were no differences in PT, ATA, and D-dimer concentration between all study groups. The aPTT was significantly shorter in bitches at the fourth and last pregnancy weeks, compared to the anestrus group, and shorter in both the fourth and last pregnancy weeks groups, compared to diestrus group. These results all support a hypercoagulable state in healthy pregnant bitches, unassociated with progesterone concentration.

Squamous cell carcinoma of the vulva in pregnancy

Two women presenting with invasive squamous cell cancer of the vulva during pregnancy are reported. The first patient was successfully treated by radical vulvectomy 2 weeks after cesarean section delivery; the second patient died of disseminated cancer despite radical vulvectomy and postoperative radiation therapy. In the second case the diagnosis was not established until 3 months after delivery. Only 12 cases of invasive squamous cell vulvar cancer during pregnancy have been previously reported. Liberal use of punch biopsy for any suspicious vulvar lesions is mandatory to enhance the potential for early diagnosis and successful treatment.

Hereditary antithrombin III deficiency with a superior sagittal sinus thrombosis: evidence for a possible mutation starting in the mother of the propositus

A patient with a superior sagittal sinus thrombosis (SSST) which occurred during the postpartum period is reported. Coagulation studies revealed persistently decreased antithrombin III (AT III) activity. Studies of AT III activity in her family revealed a hereditary AT III deficiency. Since AT III activity was normal in the grandparents of the propositus, the disorder in this family appears to be due to a spontaneous mutation occurring in the mother of the propositus.

Increased releasable vascular plasminogen activator and a bleeding diathesis

A 66-year-old man with metastatic prostatic carcinoma treated with high-dose (5 mg) diethylstilbestrol therapy underwent orchiectomy to allow discontinuation of estrogen. An extensive ecchymosis developed postoperatively in an area covered by elastic dressing tape; subsequently, it was learned that the patient had a recent history of frequent ecchymoses with mild trauma that proceeded to vesiculation. His alpha2-antiplasmin level was 132 percent, fibrin split products 4 micrograms/ml, and fibrinogen 293 mg/dl; routine coagulation results were normal. However, the level of releasable vascular plasminogen activator in a specimen drawn prior to surgery was 3.6 CTA units/ml, the highest value ever reported in this laboratory.

Antithrombin III in normal pregnancy

Plasma antithrombin III (AT III) was determined in 94 women during and after normal pregnancy employing an automated amidolytic technique. The patients were selected on the following criteria: no toxaemia, spontaneous delivery at term, birth-weight above the 10th percentile and discharged with a healthy baby. AT III levels during pregnancy and early puerperium were not lower than own control values obtained 6-8 weeks after delivery.

Plasma antithrombin III activity: an aid in the diagnosis of preeclampsia-eclampsia

Plasma antithrombin III (AT III) activity was examined retrospectively in patients with preeclampsia-eclampsia, chronic hypertension, and chronic hypertension with superimposed preeclampsia-eclampsia. Levels of AT III were greater than 1 SD below normal pregnant control in each case of preeclampsia-eclampsia syndrome. The degree of reduction in plasma AT III activity was correlated with the severity of disease. AT III activity was within normal limits in patients with chronic hypertension. AT III activity dropped prior to the appearance of clinically evident disease in three patients who were followed from an early gestational age. In no instance was low plasma AT III activity associated with normal pregnancy. Coincidental disease, including pyelonephritis and a viral syndrome, were associated with markedly decreased levels of plasma AT III activity in otherwise normal pregnancies. Plasma AT III activity may be valuable as a tool in diagnosing preeclampsia-eclampsia, as a screening test for preclinical preeclampsia-eclampsia, and as an indicator of severity of disease.

Bromocriptine compared to long-acting estrogens in lactation prevention: clinical efficacy, prolactin secretion and coagulation parameters

Sixty-eight mothers who did not want to breast-feed their babies were submitted to one of the following regimes: an intramuscular injection of estrogen (25 mg) within 1 h after delivery (n = 24) or the administration of bromocriptine for 15 or 23 days (n = 21 and 23, respectively). A careful clinical evaluation was performed every day by the same examiner during the first 7 days postpartum; blood samples were collected on days 0, 3 and 5 for human prolactin (hPRL) and estradiol, also in some cases on day 17; assays were measured by radioimmunoassay. An evaluation of the coagulation parameters was performed on day 5 in 9 estrogen-treated patients and in 25 bromocriptine-treated patients. Only 5 (11%) out of the 44 patients treated with bromocriptine experienced at least one undesirable effect of breast engorgement, in contrast to 16 (67%) out of the 24 estrogen-treated patients; this difference was statistically highly significant (P less than 0.001). Dizziness was a significant side-effect of bromocriptine treatment, occurring in 20% of the cases. In the patients in whom the administration of bromocriptine was withdrawn after 15 days, a significant mean rebound elevation of hPRL levels above the normal range occurred on the 17th day. The latter observation gives some support to earlier proposals to continue bromocriptine for up to a total 3 wk in order to avoid rebound lactation. There was no significant alteration of fibrinogen, Howell time, activated partial thromblastin time (APTT), prothrombin time (PT), thrombin time and coagulation time; mean plasminogen levels were comparable in both treated groups, while mean antithrombin III levels were increased in the bromocriptine-treated group. The significance of the latter finding requires further evaluation.

The effect of chlorotrianisene as postpartum lactation suppression on blood coagulation factors

Coagulation changes and increased risk of thromboembolic disease may occur in association with estrogen administration. The puerperium is also a high-risk period for thromboembolism, and estrogen administration at this time may increase this risk. Patients with congenital deficiency of antithrombin III have recurrent venous thromboembolic disease, suggesting that low levels of this factor may be associated with "hypercoagulability" states. We studied 50 postpartum patients who received chlorotrianisene (Tace) or placebo for lactation suppression in a prospective, double-blind, randomized fashion. Antithrombin III values were significantly lower on the third day post partum in the treated group compared to the placebo group (p less than 0.05). In addition, our clinical data from a total of 99 patients support the previous evidence that estrogens delay rather than prevent breast engorgement. Thus, with questionable benefit and a possible increased thromboembolic risk, it would appear prudent to discontinue the practice of estrogen administration for lactation suppression.

The hypercoagulability states

Although interest in coagulation has usually centered about the various hemorraghic disorders, it is hyperactivity of the hemostatic system with its thrombotic complications which has a far greater clinical impact. The hypercoagulability states are a vague group of disorders not well defined by the laboratory. They fall into two distinct groups: (1) conditions promoting venous thrombosis by activating the coagulation mechanism and (2) conditions promoting arterial thrombosis by platelet plug formation. Dealing with both of these groups separately the various disorders associated with a hypercoagulable state are discussed as well as their pathophysiologic basis; Special emphasis is placed on the laboratory evaluation of these disorders.

The effects of quinestrol and bromocriptine on blood coagulation, serum prolactin and serum FSH levels in puerperal women

The effects of bromocriptine and quinestrol upon coagulation and fibrinolysis during the puerperium were studied. Quinestrol therapy was associated with increased levels of factors VII and IX and decreased antithrombin activity on the sixth postpartum day, and increased factor IX and plasminogen levels on the fourteenth postpartum day. Six weeks after delivery elevated levels of factors II and VII and of plasminogen were recorded in women given quinestrol. Bromocriptine therapy only caused an increase in the level of factor IX at six weeks after delivery. Compared to controls, patients given bromocriptine had lower prolactin and higher FSH levels during the puerperium whereas the patients given quinestrol had increased prolactin levels and a late fall in FSH levels.

The effects of stilboestrol and quinestrol upon coagulation and fibrinolysis during the puerperium

Two oestrogens, stilboestrol and quinestrol, were used to inhibit lactation and their effects upon coagulation and fibrinolysis were compared with control patients before delivery, during the puerperium and six weeks after delivery. During the first week of the puerperium, stilboestrol therapy was associated with rises of factors IX and X and quinestrol therapy with rises of factors IX and II. Six weeks after delivery, the clotting factors were similar to the control values in those who had received stilboestrol but factor II was still raised in the quinestrol treated patients. Additionally, a significant rise of factor X in the quinestrol group was noted at this time. Plasma antithrombin levels rose during the first week of the puerperium in all three groups but, six weeks after delivery, they were lower in those who had received oestrogens. Stilboestrol and quinestrol were also associated with a rise of plasminogen and antiplasmin concentration during the first week of the puerperium. Six weeks after delivery, quinestrol treated patients still had raised levels of plasminogen and antiplasmin while the stilboestrol treated patients only had raised levels of antiplasmin. These changes in coagulation and fibrinolysis are similar to those reported during oral contraceptive therapy. The persisting changes six weeks after delivery in women who had taken quinestrol might indicate an increased thrombogenic risk when long acting oestrogen preparations are used to inhibit lactation.

Antithrombin in infancy and childhood

Antithrombin III was measured immunologically, and antithrombin activity was measured with aid of a new synthetic tripeptide substrate for serine proteases in plasma of healthy infants and children, 0-14 years of age. Both methods gave decreased values in the youngest infants as compared with adults. The antithrombin increased with age and reached adult values about 6 months of age. In infants up to one month of age, antithrombin III measured immunologically was significantly lower than antithrombin activity, whereas there was no difference between the antithrombin methods in the higher ages. Antithrombin III concentration and antithrombin activity as measured were poorly correlated.