Anticoagulation of women with prosthetic heart valves during pregnancy

Frewin, Rebecca; Chisholm, Morag

doi:10.1111/j.1471-0528.1998.tb10196.x

Cited by 18 publications

(5 citation statements)

References 43 publications

(63 reference statements)

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“…Although anticoagulation is therefore essential, the optimum method of achieving this remains controversial since no method is without risk to the mother or fetus 3 . Low molecular weight heparin is being used increasingly in obstetric practice.…”

Section: Discussionmentioning

confidence: 99%

Thromboembolism in pregnant women with mechanical prosthetic heart valves anticoagulated with low molecular weight heparin

Roberts

Ross

Flint

et al. 2001

BJOG

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A 33 year old woman had undergone a mechanical prosthetic (Starr-Edwards) mitral valve replacement for valvular damage due to rheumatic heart disease, having had three spontaneous vaginal deliveries prior to her cardiac surgery. She conceived while on warfarin and was converted at six weeks of gestation to tinzaparin treatment dose (175 units/kg) by once daily subcutaneous injection; anti-Xa levels were not monitored. She presented at 26 weeks of gestation with a right-sided hemiplegia and dysphasia. A CT scan revealed a left parietal lobe infarct.She was treated initially with adjusted dose unfractionated heparin, maintaining activated partial thromboplastin time of 2.0 to 2.5 times the control. She was subsequently switched to warfarin and aspirin (150 mg/ d). She made a satisfactory recovery and continued on warfarin until 32 weeks of gestation when she was converted to another low molecular weight heparin, dalteparin, given by twice daily injection (100u/kg). Anti-Xa levels were in the therapeutic range at 0.9 u/ mL (0.4-1.0 u/mL). She was delivered of a healthy infant by uncomplicated elective caesarean section at 34 weeks and was warfarinised postnatally. Case report 2A 28 year old woman in her fourth pregnancy had undergone a mechanical prosthetic (Starr-Edwards) mitral valve replacement, also for valvular damage secondary to rheumatic fever as a child. Her past obstetric history included two early terminations of pregnancy and one emergency caesarean section for severe pre-eclampsia at 32 weeks of gestation in 1993. She was anticoagulated with warfarin during the latter pregnancy. Since her mitral valve replacement she had been poorly compliant on warfarin and had suffered a left temporoparietal infarct.She conceived while taking warfarin and was converted to tinzaparin (175 units/kg) at eight weeks of gestation, which was administered, as a once daily dose, under supervision on a daily outpatient basis. At 11 weeks of gestation she was found collapsed at home and on admission had a dense right-sided hemiparesis and aphasia. A CT scan showed an old left tempoparietal infarct with no new areas of haemorrhage and a clinical diagnosis of a thrombotic cerebrovascular accident was made. Her anti-Xa levels measured on admission were therapeutic. She was treated with intravenous unfractionated heparin, maintaining the activated partial thromboplastin time of 2.0 and 2.5 times the control, and then restarted on therapeutic doses of tinzaparin until 16 weeks of gestation when she was re-warfarinised.At 30 weeks of gestation she developed acute pulmonary ooedema secondary to fast atrial ®brillation and underwent an emergency caesarean section due to deterioration in her clinical state. Prior to this deterioration the International Normalised Ratio (INR) was maintained in the therapeutic range. There was no suggestion that the deterioration in the clinical state was due to thrombotic complications. Case report 3A 23 year old woman developed haemoptysis and shortness of breath during her ®rst pregnancy in 1995. She ...

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Section: Discussionmentioning

confidence: 99%

Thromboembolism in pregnant women with mechanical prosthetic heart valves anticoagulated with low molecular weight heparin

Roberts

Ross

Flint

et al. 2001

BJOG

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“…The reported incidence of warfarin embryopathy has varied and has been a subject of debate (62,63). Although recent authoritative text has estimated the incidence of warfarin embryopathy to be as low as 1.6% of live births (1), one recent review indicated an incidence of 6.4% (33), and another review indicated 7.4% (64). Furthermore, these reviews probably represent an underestimation, due to the retrospective nature and lack of pathological assessment of the aborted fetuses in most series (64).…”

Section: Management Of Complicationsmentioning

confidence: 99%

“…Although recent authoritative text has estimated the incidence of warfarin embryopathy to be as low as 1.6% of live births (1), one recent review indicated an incidence of 6.4% (33), and another review indicated 7.4% (64). Furthermore, these reviews probably represent an underestimation, due to the retrospective nature and lack of pathological assessment of the aborted fetuses in most series (64). This assumption is supported by a prospective study reporting facial defects suggestive of warfarin embryopathy in 29% of viable offspring (65) and two recent retrospective studies reporting skeletal deformity and nasal hypoplasia in 10% of babies exposed to warfarin (14,66).…”

Section: Management Of Complicationsmentioning

confidence: 99%

Valvular Heart Disease and Pregnancy

Elkayam

Bitar

2005

Journal of the American College of Cardiology

230

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A large number of prosthetic heart valves (PHV) are being implanted in patients with both congenital and acquired valvular disease. Many of the recipients of such valves are women of childbearing age who desire to have children. The main issues involved with pregnancy in a patient with PHV include the selection of PHV in women during their childbearing age, risks to both the mother and the fetus associated with pregnancy and the management of the patients with PHV during gestation.

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“…Some articles recommend using heparin only during weeks 6 to 12 and then after week 32 [23], but it is unclear if this approach entirely eliminates the risk of fetal malformation and still places the fetus at risk of warfarin-induced intracranial hemorrhage. Standard heparin should be started at a dose of 17,500 to 20,000 units every 12 hours to achieve a goal aPTT that corresponds to an anti-Xa level of 0.3 to 0.7 U/mL [3,7,24]. If LMWH is used one should start with a dose of enoxaparin 1 mg/kg every 12 hours and monitor anti-Xa levels.…”

Section: Pregnancymentioning

confidence: 99%

Anticoagulant therapy in special circumstances

DeLoughery

2000

Curr Cardiol Rep

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Situations often occur in anticoagulated patients that require adjustment of anticoagulation therapy. These situations often place the patient at risk of bleeding, and often there is little clinical data to guide the clinician. This paper reviews several of these situations and offers guidance for the management of patients. The problems reviewed concern the patient on anticoagulants who is or desires to get pregnant, peri-operative management of anticoagulated patients, anticoagulated patients with intracranial bleeding or endocarditis, and the "warfarin refractory" patient.

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Anticoagulation of women with prosthetic heart valves during pregnancy

Cited by 18 publications

References 43 publications

Thromboembolism in pregnant women with mechanical prosthetic heart valves anticoagulated with low molecular weight heparin

Thromboembolism in pregnant women with mechanical prosthetic heart valves anticoagulated with low molecular weight heparin

Valvular Heart Disease and Pregnancy

Anticoagulant therapy in special circumstances

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