anticoagulation-pregnancy

Anticoagulation in Pregnancy and the puerperium : 

Anticoagulation in Pregnancy and the puerperium Dr. Mohammed Abdalla Egypt, Domiat G. Hospital

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, the optimal use of anticoagulants during pregnancy remains controversial because of a lack of appropriate prospective randomized clinical trials.

Before Initiating Anticoagulant Therapy : 

Before Initiating Anticoagulant Therapy full thrombophilia screen (provide information that can influence the duration and intensity of anticoagulation) full blood count and a coagulation screen urea, electrolytes and liver-function tests, to exclude renal or hepatic dysfunction, which are cautions for anticoagulant therapy

Prophylactic Anticoagulation : 

Prophylactic Anticoagulation 1.    What are the criteria of risk assessment? 2.    Who are the patients candidates for PROPHYLACTIC anticoagulation ? 3.    What are the hazards of anticoagulation during pregnancy? 4.    Unfractionated or fractionated heparin and in which dose?

what are the criteria of risk assessment? : 

what are the criteria of risk assessment? increased parity. advanced maternal age. obesity. operative delivery. Any persistent and identifiable hypercoagulable state .either acquired or inherited.( thrombophilia.).

RISK CATEGORY : 

RISK CATEGORY HIGH RISK Pr.TED +thrombophilia Pr.TED +family history. Recurrent TEDs. TED in current pregnancy Prosthetic mitral valve LOW RISK ONE previous TED.

thrombophilia : 

thrombophilia INHERETED ACQURED Protein C deficiency. Protein S deficiency. AT3 deficiency Factor V leiden mutation Homocystinuria APhS. Myeloproliferative disease. Malignancy. Nephrotic syndrome.

who are the patients candidates for PROPHYLACTIC anticoagulation ? : 

who are the patients candidates for PROPHYLACTIC anticoagulation ? —1-patients judged at low risk:  these patients are though to be most vulnerable from the time of delivery throughout the puerperium which is the period of greatest risk. With low dose asprin antenatally.

who are the patients candidates for PROPHYLACTIC anticoagulation ? : 

2--patients judged at high risk: these patients receive antenatal ,intranatal ,and postnatal anticoagulation. and throughout the puerperium,. who are the patients candidates for PROPHYLACTIC anticoagulation ?

What are the Hazards of anticoagulation during pregnancy? : 

What are the Hazards of anticoagulation during pregnancy? The platelet count should be monitored on a monthly basis to detect heparin-induced thrombocytopenia, which is associated with further thrombotic complications.

What are the Hazards of anticoagulation during pregnancy? : 

Low molecular weight heparins are a promising alternative because of their long half-lives which give a more predictable dose-effect and reduce the number of daily injections. The risk of heparin-induced thrombocytopaenia is lower. At present, their legal prescription is limited to the 2nd and 3rd terms of pregnancy as prophylactic treatment. What are the Hazards of anticoagulation during pregnancy?

Thromboembolic Disease in Pregnancy and the Puerperium Acute Management : 

Thromboembolic Disease in Pregnancy and the Puerperium Acute Management In women with factors consistent with VTE, anticoagulant treatment should be employed until an objective diagnosis is made RCOG guideline A

Initial treatment of VTE during pregnancy : 

Initial treatment of VTE during pregnancy In clinically suspected DVT or PTE, treatment with unfractionated heparin or low molecular weight heparin (LMWH) should be given until the diagnosis is excluded by objective testing, unless treatment is strongly contraindicated. RCOG guideline A

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Two RCTs of unfractionated heparin in acute DVT showed that failure to achieve the lower limit of the target therapeutic range of the activated partial thromboplastin time (APTT) ratio(at least twice control ), was associated with a 10-15 fold increase in the risk of recurrent VTE.*. Descriptive studies indicate high risks of recurrent VTE and death when heparin was withheld from patients with suspected or proven VTE, compared with low risks when heparin was given. (Evidence level 1b supported by levels II & III). *Hyers TM, Hull RD, Weg JG. Antithrombotic therapy for venous thromboembolic disease. Chest 1995: 108:335-51s.

, why it may be useful to determine the anti-Xa level as a measure of heparin dose (target range 0.35-0.7 u/ml)?* : 

, why it may be useful to determine the anti-Xa level as a measure of heparin dose (target range 0.35-0.7 u/ml)?* There is an increasing realisation that APTT monitoring of unfractionated heparin is frequently poorly performed and is technically problematic** *Hirsh J. Heparin. N Engl J Med 1991;324:1565-74 **Wheeler AP, Jaquiss RDB, Newman JH. Physician practices in the treatment of pulmonary embolism and deep vein thrombosis. Arch Intern Med 1988;148:1321-5.

, why it may be useful to determine the anti-Xa level as a measure of heparin dose (target range 0. 35-0.7 u/ml)? : 

Apparent heparin resistance occurs in late pregnancy due to increased fibrinogen and factor VIII which influence the APTT. , why it may be useful to determine the anti-Xa level as a measure of heparin dose (target range 0. 35-0.7 u/ml)?

Heparin Regimens May Include : 

Heparin Regimens May Include Continuous intravenous infusion of unfractionated heparin, Subcutaneous injections of unfractionated heparin . Subcutaneous injections of LMWH. Therapeutic Heparinisation

Intravenous unfractionated Heparin : 

Intravenous unfractionated Heparin 2500U in 500ml saline 10 drops/min 7 drops/min 1500u/hour 1000u/hour an initial infusion concentration of 1000 iu/ml should be employed; 1

Intravenous unfractionated heparin : 

Measure aPTT level six hours after the loading dose, then at least daily. The dose should be adjusted to achieve a therapeutic target range within 24 hours.(60-90sec.). The therapeutic target aPTT ratio is usually 1.5-2.5 times the average laboratory control value.. Measure APTT level six hours after the loading dose, then at least daily. The dose should be adjusted to achieve a therapeutic target range within 24 hours.* The target range for the anti-Xa level in this situation is 0.35-0.70 iu/ml. Intravenous unfractionated heparin *Hyers TM, Hull RD, Weg JG. Antithrombotic therapy for venous thromboembolic disease. Chest 1995: 108:335-51s.

Subcutaneous unfractionated Heparin : 

Subcutaneous unfractionated heparin is an effective alternative to intravenous unfractionated heparin for the initial management of DVT. . Subcutaneous unfractionated Heparin RCOG Evidence Level I & II 2

Subcutaneous unfractionated Heparin : 

Initial intravenous bolus of 5000 iu and then subcutaneous injections of 15,000-20 000 iu, 12 hourly. Subcutaneous unfractionated Heparin mid-interval aPTT maintained between 1.5-2.5 times the control.

Low Molecular Weight Heparin : 

LMWHs are more effective than unfractionated heparin with lower mortality and fewer haemorrhagic complications in the initial treatment of DVT in nonpregnant subjects. LMWHs are as effective as unfractionated heparin for treatment of PTE. Low Molecular Weight Heparin RCOG evidence level A 3

Low Molecular Weight Heparin : 

a twice-daily dosage regimen for LMWHs in the treatment of VTE in pregnancy IS recommended . Low Molecular Weight Heparin Long-term use of LMWHs may be associated with a lower risk of osteoporosis and bone fractures than unfractionated heparin.* *Monreal M. Long-term treatment of venous thromboembolism with low-molecular weight heparin. Curr Opin Pulm Med 2000;6:326-9.

Low molecular weight heparin : 

Peak anti-Xa activity (three hours post-injection) should be measured. The target therapeutic range for LMWH (0.6-1.0 units/ml) appears satisfactory. And the dose of LMWH should be reduced if the target therapeutic range is above the upper limit. Low molecular weight heparin The platelet count should be rechecked seven to nine days after commencing treatment.

Maintenance Treatment of DVT or PTE : 

Maintenance Treatment of DVT or PTE The simplified therapeutic regimen for LMWH is convenient for patients and allows out-patient treatmen oral anticoagulants are generally avoided for maintenance therapy in pregnancy especially before 13wk. and after 36wk.* The platelet count should be monitored on a monthly basis to detect heparin-induced thrombocytopenia, *Chan WS, Anand S, Ginsberg JS. Anticoagulation of pregnant women with mechanical heart valves: A systematic review of the literature. Arch Intern Med 2000;160:191-6

Women with antenatal VTE can be managed with an adjusted-dose regimen of subcutaneous unfractionated heparin or subcutaneous LMWH for the remainder of the pregnancy.**** : 

Women with antenatal VTE can be managed with an adjusted-dose regimen of subcutaneous unfractionated heparin or subcutaneous LMWH for the remainder of the pregnancy.**** *Thomson AJ, Walker ID, Greer IA. Low molecular weight heparin for the immediate management of thromboembolic disease in pregnancy. Lancet 1998;352:1904. *Monreal M. Long-term treatment of venous thromboembolism with low-molecular weight heparin. Curr Opin Pulm Med 2000;6:326-9. *Hull RD, Delmore T, Carter C, et al. Adjusted subcutaneous heparin versus warfarin sodium in the long-term treatment of venous thrombosis. N Engl J Med 1982;306:189-94. *British Society for Haematology. Guidelines on the prevention, investigation, and management of thrombosis associated with pregnancy. J Clin Pathol 1993;46:489-96.

Anticoagulant Therapy During Labour and Delivery, Including the Use of Epidurals : 

Anticoagulant Therapy During Labour and Delivery, Including the Use of Epidurals The dose of heparin should be reduced to its thromboprophylactic dose on the day prior to induction of labour and continued in this dose during labour*** unfractionated heparin LMWH preparations 5000iu/12h Once daily *Thomson AJ, Greer IA. Non-haemorrhagic obstetric shock. Best Practice and Research in Clinical Obstetrics and Gynaecology 2000;14:19-41 . *Dahlman TC, Hellgren MS, Blomback M. Thrombosis prophylaxis in pregnancy with use of subcutaneous heparin adjusted by monitoring heparin concentration in plasma. Am J Obstet Gynecol 1989;161:420-5.40 *Toglia MR, Weg JG. Venous thromboembolism during pregnancy. N Engl J Med 1996;335:108-14. or

The Treatment Dose (Twice Daily Administration) Should Be Recommenced Following Delivery. : 

The Treatment Dose (Twice Daily Administration) Should Be Recommenced Following Delivery. For delivery by elective caesarean section, the woman should receive a thromboprophylactic dose of LMWH on the day prior to delivery and, on the day of delivery, the morning dose should be omitted and the operation performed that morning. The thromboprophylactic dose of LMWH should be given by three hours post-operatively (over four hours after removal of the epidural catheter, if appropriate) and the treatment dose recommenced that evening.

Anticoagulant therapy during labour and delivery, including the use of epidurals : 

To minimise or avoid the risk of epidural haematoma, regional techniques should not be used until at least 12 hours after the previous prophylactic dose of LMWH. When a woman presents while on a therapeutic regimen of LMWH (i.E. A twice-daily regimen), regional techniques should not be employed for at least 24 hours after the last dose of LMWH.** Anticoagulant therapy during labour and delivery, including the use of epidurals *Checketts MR, Wildsmith JA. Central nerve block and thromboprophylaxis - is there a problem? Br J Anaesth 1999;82:164-7.42 *Gogarten W, Van Aken H, Wulf H, et al. Ruckenmarksnahe regionalanassthesien und thromboembolieprophylaxe/antikoagulation. Anasthesiol Intensivmed 1997;12:623-8.

For Delivery by Elective Caesarean Section : 

For Delivery by Elective Caesarean Section on the day prior to deliverythe woman should receive a thromboprophylactic dose of LMWH on the day of deliverythe morning dose should be omitted and the operation performed that morning The thromboprophylactic dose of LMWH should be given by three hours post-operatively (over four hours after removal of the epidural catheter, if appropriate) and the treatment dose recommenced that evening. RCOG guideline RCOG guideline

Postnatal Anticoagulation : 

Postnatal Anticoagulation It is recommended that anticoagulant treatment should be continued postnatally for 6-12 weeks, At three months, the woman should be assessed for continuing risk factors for VTE. Warfarin is not contraindicated in breastfeeding. There are no published data on whether LMWHs are secreted in breast milk, although experience of enoxaparin in the puerperium reports no problems during breastfeeding and other heparins are known not to cross the breast. Prandoni P. Simioni P. Girolami A. Antiphospholipid antibodies, recurrent thromboembolism, and intensity of warfarin anticoagulation. Thromb Haemost 1996;75:859. 46 Nelson-Piercy C. Hazards of heparin. In: Greer IA, editor. Thrombo-embolic disease in obstetrics and gynaecology. Baillière's Clin Obstet Gynaecol 1997;11:489-509.

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thank you