Fetotoxicity of warfarin anticoagulation

Hematological profiles of newborns of mothers with hypertensive disorders of pregnancy delivered at the University of Gondar comprehensive specialized hospital: a comparative cross-sectional study

BACKGROUND

Hypertensive disorders in pregnancy can cause prenatal placental perfusion with insufficient blood supply to the fetus, resulting in fetal exposure to hypoxia and leading to disturbance of neonatal hematopoietic stem cells. This study aimed to compare the hematological profiles of newborns from mothers with hypertensive disorders and normotensive delivered at the University of Gondar comprehensive specialized hospital.

METHODS

A comparative cross-sectional study was conducted from March to May 2022 among 308 newborns from hypertensive and normotensive mothers in equal proportions. A systematic random sampling technique was used to select study participants. Three milliliters of cord blood were collected to perform a complete blood count by Beckman coulter. The results were presented using tables and graphs. Independent t-test and Mann-Whitney U test were done to compare the hematological profiles of the two groups. P-value < 0.05were considered statistically significant.

RESULTS

The majority of hypertensive and normotensive mothers' ages were between 20 and 34 years (83.77% and 90.91%, respectively). The hematocrit levels were significantly higher in neonates of hypertensive mothers than the neonates of normotensive mothers (49.10 ± 5.19% and 46.09 ± 7.63% respectively) (P < 0.001) while neutrophil counts were significantly lower in neonates of hypertensive mothers than the neonates of normotensive mothers (6.62 ± 3.30 and 7.55 ± 3.31 × 103 /ul respectively) (P = 0.007). Also, platelets counts were significantly lower in neonates of hypertensive mothers than neonates of normotensive mothers (221.25 ± 83.56 and 260.24 ± 83.01 × 103/ul respectively) (P < 0.001). The platelet and nucleated red blood cell count showed a statistically significant difference among newborns from mothers with superimposed preeclampsia and gestational hypertension.

CONCLUSION

Newborns delivered from hypertensive disorders of pregnancy had low white blood cell parameters, low platelet count and high red blood cell parameters compared to controls. As result, newborns may develop leukopenia, thrombocytopenia and polycythemia, respectively. Therefore, newborns should be monitored for early detection and follow-up of hematological abnormalities before complications occurred.

Zebrafish Models to Study Ectopic Calcification and Calcium-Associated Pathologies

Ectopic calcification refers to the pathological accumulation of calcium ions in soft tissues and is often the result of a dysregulated action or disrupted function of proteins involved in extracellular matrix mineralization. While the mouse has traditionally been the go-to model organism for the study of pathologies associated with abnormal calcium deposition, many mouse mutants often have exacerbated phenotypes and die prematurely, limiting the understanding of the disease and the development of effective therapies. Since the mechanisms underlying ectopic calcification share some analogy with those of bone formation, the zebrafish (Danio rerio)-a well-established model for studying osteogenesis and mineralogenesis-has recently gained momentum as a model to study ectopic calcification disorders. In this review, we outline the mechanisms of ectopic mineralization in zebrafish, provide insights into zebrafish mutants that share phenotypic similarities with human pathological mineralization disorders, list the compounds capable of rescuing mutant phenotypes, and describe current methods to induce and characterize ectopic calcification in zebrafish.

Dentofacial manifestations of fetal warfarin syndrome in a paediatric patient

Anticoagulant therapy is commonly indicated during pregnancy to prevent thrombosis and prevention of prosthetic heart valve-associated thromboembolic events. Warfarin is a synthetic anticoagulant with low molecular weight and can cross the placenta resulting in congenital abnormalities termed fetal warfarin syndrome. This paper highlights the case of an 8-year-old boy with warfarin embryopathy. It highlights the extraoral and intraoral findings of the case along with the cephalometric analysis and provides insight into the phenotypic variations among the different cases reported in the literature.

Effects of Anti-vitamin k oral anticoagulants on bone and cardiovascular health

Vitamin K antagonist oral anticoagulants (VKAs) have been proven over 50 years to be highly effective and acceptably safe in many settings and are still used by millions of people worldwide. The main concern about the safety of VKAs regards the risk of bleeding, but there is accumulation evidence of their potentially negative effects beyond hemostasis. Indeed, VKAs impair the action of several Vitamin-K Dependent Proteins (VKDP), such as Bone Gla protein, Matrix Gla protein, Gas6 Protein, Periostin and Gla-Ric Protein, involved in bone and vascular metabolism, thus exerting a detrimental effect on bone and vascular health. Indeed, although the evidence regarding this issue is not compelling, it has been shown that VKAs use decreases bone mass density, increases the risk of bone fractures and accelerates the process of vascular and valvular calcification. Vascular calcification is a major concern in Chronic Kidney Disease (CKD) patients, also in absence of VKAs, because of mineral metabolism derangement, chronic inflammation and oxidative stress. Direct Oral AntiCoagulants (DOACs) do not affect VKDP involved in vascular and valvular calcification, and do not induce calcific valve degeneration in animal models, being a possible alternative to AVK for CKD patients. However, the efficacy and safety of DOACs in this population, suggested by some recent observations, requires confirmation by dedicated, randomized study. We reviewed here the effects of VKAs in bone and vascular health as compared to DOACs, in order to provide the physicians with some data useful to wisely choose the most suitable anticoagulant for every patient.

New Insights on Vitamin K Metabolism in Senegalese sole (Solea senegalensis) Based on Ontogenetic and Tissue-Specific Vitamin K Epoxide Reductase Molecular Data

Vitamin K (VK) is a key nutrient for several biological processes (e.g., blood clotting and bone metabolism). To fulfill VK nutritional requirements, VK action as an activator of pregnane X receptor (Pxr) signaling pathway, and as a co-factor of γ-glutamyl carboxylase enzyme, should be considered. In this regard, VK recycling through vitamin K epoxide reductases (Vkors) is essential and should be better understood. Here, the expression patterns of vitamin K epoxide reductase complex subunit 1 (vkorc1) and vkorc1 like 1 (vkorc1l1) were determined during the larval ontogeny of Senegalese sole (Solea senegalensis), and in early juveniles cultured under different physiological conditions. Full-length transcripts for ssvkorc1 and ssvkorc1l1 were determined and peptide sequences were found to be evolutionarily conserved. During larval development, expression of ssvkorc1 showed a slight increase during absence or low feed intake. Expression of ssvkorc1l1 continuously decreased until 24 h post-fertilization, and remained constant afterwards. Both ssvkors were ubiquitously expressed in adult tissues, and highest expression was found in liver for ssvkorc1, and ovary and brain for ssvkorc1l1. Expression of ssvkorc1 and ssvkorc1l1 was differentially regulated under physiological conditions related to fasting and re-feeding, but also under VK dietary supplementation and induced deficiency. The present work provides new and basic molecular clues evidencing how VK metabolism in marine fish is sensitive to nutritional and environmental conditions.

Laboratory assessment of vitamin K status

Vitamin K is required for the ɣ-carboxylation of specific glutamic acid residues within the Gla domain of the 17 vitamin K-dependent proteins (VKDPs). The timely detection and correction of vitamin K deficiency can protect against bleeding. Vitamin K also plays a role in bone metabolism and vascular calcification. Patients at increased risk of vitamin K deficiency include those with a restricted diet or malnutrition, lipid malabsorption, cancer, renal disease, neonates and the elderly. Coagulation assays such as the prothrombin time have been used erroneously as indicators of vitamin K status, lacking sufficient sensitivity and specificity for this application. The measurement of phylloquinone (K1) in serum is the most commonly used marker of vitamin K status and reflects abundance of the vitamin. Concentrations <0.15 µg/L are indicative of deficiency. Disadvantages of this approach include exclusion of the other vitamin K homologues and interference from recent dietary intake. The cellular utilisation of vitamin K is determined through measurement of the prevalence of undercarboxylated VKDPs. Most commonly, undercarboxylated prothrombin (Protein Induced by Vitamin K Absence/antagonism, PIVKA-II) is used (reference range 17.4–50.9 mAU/mL (Abbott Architect), providing a retrospective indicator of hepatic vitamin K status. Current clinical applications of PIVKA-II include supporting the diagnosis of vitamin K deficiency bleeding of the newborn, monitoring exposure to vitamin K antagonists, and when used in combination with α-fetoprotein, as a diagnostic marker of hepatocellular carcinoma. Using K1 and PIVKA-II in tandem is an approach that can be used successfully for many patient cohorts, providing insight into both abundance and utilisation of the vitamin.

Warfarin-exposed zebrafish embryos resembles human warfarin embryopathy in a dose and developmental-time dependent manner - From molecular mechanisms to environmental concerns

Warfarin is the most worldwide used anticoagulant drug and rodenticide. Since it crosses placental barrier it can induce warfarin embryopathy (WE), a fetal mortality in neonates characterized by skeletal deformities in addition to brain hemorrhages. Although the effects of warfarin exposure in aquatic off target species were already described, the particular molecular toxicological mechanisms during early development are still unclear. Here, we used zebrafish (Danio rerio) to describe and compare the developmental effects of warfarin exposure (0, 15.13, 75.68 and 378.43 mM) on two distinct early developmental phases (embryos and eleuthero-embryos). Although exposure to both developmental phases induced fish mortality, only embryos exposed to the highest warfarin level exhibited features mimicking mammalian WE, e.g. high mortality, higher incidence of hemorrhages and altered skeletal development, among other effects. To gain insights into the toxic mechanisms underlying warfarin exposure, the transcriptome of embryos exposed to warfarin was explored through RNA-Seq and compared to that of control embryos. 766 differentially expressed (564 up- and 202 down-regulated) genes were identified. Gene Ontology analysis revealed particular cellular components (cytoplasm, extracellular matrix, lysosome and vacuole), biological processes (mainly amino acid and lipid metabolism and response to stimulus) and pathways (oxidative stress response and apoptosis signaling pathways) being significantly overrepresented in zebrafish embryos upon warfarin exposure. Protein-protein interaction further evidenced an altered redox system, blood coagulation and vasculogenesis, visual phototransduction and collagen formation upon warfarin exposure. The present study not only describes for the first time the WE in zebrafish, it provides new insights for a better risk assessment, and highlights the need for programming the rat eradication actions outside the fish spawning season to avoid an impact on off target fish community. The urge for the development of more species-specific anticoagulants for rodent pest control is also highlighted.

High-Versus Low-Dose Warfarin-Related Teratogenicity: A Case Report and Systematic Review

OBJECTIVE

The optimal anticoagulant therapy during pregnancy in women with mechanical heart valves remains controversial. This study highlights a case of high-dose warfarin ingestion throughout pregnancy and performed a systematic review to assess rates of teratogenicity with high versus low warfarin dosing (≤5 mg daily).

METHODS

A literature search for all case reports and available literature was conducted in PubMed, Medline, and EMBASE up to December 2016 using medical subject heading terms "mechanical prosthetic valves," "pregnancy," "oral anticoagulants," "warfarin," "coumarins," "heparin, low-molecular-weight," and "thromboembolism." To be included, warfarin had to be administered anytime between 6 and 12 weeks of gestation with the dose being specified. The Newcastle-Ottawa Scale was used to assess quality of the cohort data.

RESULTS

The woman in the studied case received the highest reported warfarin doses throughout pregnancy (14.5-16.5 mg daily) and delivered a baby with no evidence of teratogenicity to the current age of 5 years. The study identified 23 case reports, with all demonstrating warfarin teratogenicity regardless of high-dose (n = 12) or low-dose (n = 11) warfarin. Twelve cohort studies identified a warfarin teratogenicity rate of 5.0%, with rates of 2.4% and 10.5% with low- and high-dose warfarin, respectively. Risk of bias was moderate (median Newcastle-Ottawa Scale score of 6) for all of the cohort studies.

CONCLUSION

Although a lower prevalence of warfarin-induced teratogenicity is reported with low-dose warfarin, a safe "cut-off" dose is misleading. Teratogenic risk with warfarin is unpredictable, mandating individual decisions regardless of the dose.

Adherence to Long-Term Follow-Up of Patients with Life-Threatening, Inhaled Synthetic Cannabinoids-Associated Coagulopathy in Chicago

A large-scale outbreak of life-threatening, inhaled synthetic cannabinoids (Spice/K2)-associated coagulopathy with bleeding complications was recently reported in Illinois. The causative agents were brodifacoum, difenacoum, and bromadiolone, potent, long-acting, 4-hydroxycoumarin anticoagulant rodenticides (LAAR) that were mixed with Spice/K2 products procured and then inhaled by the victims. We report on 3 poisoned patients who reside in underserved, socioeconomically disadvantaged neighborhoods of Chicago that were admitted and treated successfully at two inner-city, tertiary care hospitals in Chicago. The patients were discharged from the hospitals on daily long-term high-dose oral vitamin K₁ (VK₁), provided free of charge. However, 2 patients were lost to follow-up prior to safe discontinuation of oral VK₁ therapy. The third patient was treated and followed successfully for 7 months when VK₁ was discontinued. We conclude that prolonged oral VK₁ therapy and follow-up of acute, life-threatening LAAR poisoning are variable and present challenges to healthcare providers. Appropriate practice guidelines to improve patient access and adherence to daily high-dose oral VK₁ therapy and follow-up should be developed and implemented.

An evidence-based approach to pre-pregnancy counselling for patients with systemic lupus erythematosus

Patients with SLE are often young females of childbearing age and a pregnancy wish in this patient group is common. However, SLE patients are at high risk for adverse pregnancy outcomes that require adequate guidance. It is widely acknowledged that pre-pregnancy counselling is the pivotal first step in the management of SLE patients with a wish to become pregnant. Next, management of these patients is usually multidisciplinary and often requires specific expertise from the different physicians involved. Very recently a EULAR recommendation was published emphasizing the need for adequate preconception counselling and risk stratification. Therefore the present review specifically addresses the issue of pre-pregnancy counselling for SLE patients with an evidence-based approach. The review summarizes data retrieved from recently published, high-quality cohort studies that have contributed to a better understanding and estimation of pregnancy-related risks for SLE patients. The present review categorizes risks from a patient-oriented point of view, that is, the influence of pregnancy on SLE, of SLE on pregnancy, of SLE on the foetus/neonate and of SLE-related medication. Lastly, pre-pregnancy counselling of SLE patients with additional secondary APS is reviewed. Collectively these data can guide clinicians to formulate appropriate preventive strategies and patient-tailored monitoring plans during pre-pregnancy counselling of SLE patients.

Thrombolysis for Venous Thromboembolism During Pregnancy: A Literature Review

BACKGROUND

Pregnancy is a hypercoagulable state, conferring an increased risk of venous thromboembolism (VTE). However, treatment algorithms for deep venous thrombosis and pulmonary embolism are based on studies of nonpregnant patients.

METHODS

A literature review of cases in which thrombolysis was used for the treatment of VTE during pregnancy was conducted using the PubMed (National Institutes of Health) database.

RESULTS

A PubMed database search of English language articles for reports of thrombolysis for the treatment of VTE in pregnancy identified 215 cases, including 183 cases of systemic thrombolysis, 19 cases of catheter-directed thrombolysis, and 13 cases of mechanical thrombectomy. For systemic thrombolysis, the maternal complication rate was 4.40% and the fetal complication rate was 1.65%. For catheter-directed thrombolysis, the maternal complication rate was 14.75% and the fetal complication rate was 5.2%. In cases of mechanical thrombectomy, there were no reported maternal or fetal complications.

CONCLUSIONS

Although conservative strategies are preferred in pregnancy, thrombolysis is an adjunct for limb or life-threatening VTE. Review of past reports suggests low rates of maternal and fetal complications following systemic thrombolysis and mechanical thrombectomy but higher rates of complications after catheter-directed thrombolysis in the treatment of VTE during pregnancy.

Effects of warfarin on biological processes other than haemostasis: A review

Warfarin is the world's most widely used anticoagulant drug. Its anticoagulant activity is based on the inhibition of the vitamin K-dependent (VKD) step in the complete synthesis of a number of blood coagulation factors that are required for normal blood coagulation. Warfarin also affects synthesis of VKD proteins not related to haemostasis including those involved in bone growth and vascular calcification. Antithrombotic activity of warfarin is considered responsible for some aspects of its anti-tumour activity of warfarin. Some aspects of activities against tumours seem not to be related to haemostasis and included effects of warfarin on non-haemostatic VKD proteins as well as those not related to VKD proteins. Inflammatory/immunomodulatory effects of warfarin indicate much broader potential of action of this drug both in physiological and pathological processes. This review provides an overview of the published data dealing with the effects of warfarin on biological processes other than haemostasis.

Matrix Gla protein deficiency impairs nasal septum growth, causing midface hypoplasia

Genetic and environmental factors may lead to abnormal growth of the orofacial skeleton, affecting the overall structure of the face. In this study, we investigated the craniofacial abnormalities in a mouse model for Keutel syndrome, a rare genetic disease caused by loss-of-function mutations in the matrix Gla protein (MGP) gene. Keutel syndrome patients show diffuse ectopic calcification of cartilaginous tissues and impaired midface development. Our comparative cephalometric analyses of micro-computed tomography images revealed a severe midface hypoplasia in Mgp-/- mice. In vivo reporter studies demonstrated that the Mgp promoter is highly active at the cranial sutures, cranial base synchondroses, and nasal septum. Interestingly, the cranial sutures of the mutant mice showed normal anatomical features. Although we observed a mild increase in mineralization of the spheno-occipital synchondrosis, it did not reduce the relative length of the cranial base in comparison with total skull length. Contrary to this, we found the nasal septum to be abnormally mineralized and shortened in Mgp-/- mice. Transgenic restoration of Mgp expression in chondrocytes fully corrected the craniofacial anomalies caused by MGP deficiency, suggesting a local role for MGP in the developing nasal septum. Although there was no up-regulation of markers for hypertrophic chondrocytes, a TUNEL assay showed a marked increase in apoptotic chondrocytes in the calcified nasal septum. Transmission electron microscopy confirmed unusual mineral deposits in the septal extracellular matrix of the mutant mice. Of note, the systemic reduction of the inorganic phosphate level was sufficient to prevent abnormal mineralization of the nasal septum in Mgp-/-;Hyp compound mutants. Our work provides evidence that modulation of local and systemic factors regulating extracellular matrix mineralization can be possible therapeutic strategies to prevent ectopic cartilage calcification and some forms of congenital craniofacial anomalies in humans.

Therapeutic warfarin use and the extrahepatic functions of vitamin K-dependent proteins

The impact of warfarin therapy on the functions of extrahepatic vitamin K-dependent proteins (VKDP) is less clearly understood and less widely recognised in clinical practice than that on the hepatic counterparts (clotting factors II, VII, IX and X). Warfarin inhibits osteocalcin, an abundant extrahepatic VKDP involved in the mineralisation and maturation of bone and thus, primarily by this mechanism, may have an adverse effect on bone health. Whilst some studies do link warfarin use to an increase in osteoporosis and fracture risk others have not. Warfarin also inhibits the extrahepatic VKDP matrix gla protein (MGP) which acts to prevent ectopic calcification of the vasculature. Studies have consistently found a correlation between warfarin use and vascular calcification with inhibition of MGP believed to be the main cause. Inhibition of MGP also appears to explain warfarin's well established teratogenic effect. Further adverse effects may also arise from warfarin's inhibition of other known extrahepatic VKDPs. The available evidence is intriguing, and suggests that the impact of warfarin on the extrahepatic functions of vitamin K-dependent proteins warrants further careful consideration.

Pregnancy outcome in patients exposed to direct oral anticoagulants - and the challenge of event reporting

Today, direct oral anticoagulants (DOAC) are widely used alternatives to Vitamin-K antagonists (VKA). Women of reproductive age may become pregnant during anticoagulation and, while VKA carry an embryotoxic potential, the risk of DOAC embryopathy is unknown. As a result, some patients elect to terminate pregnancy for fear of DOAC embryotoxicity. To assess the risk of DOAC embryopathy, we reviewed cases of DOAC exposure in pregnancy collected from physicians, literature and pharmacovigilance systems of drug authorities and manufacturers. A total of 357 reports including duplicates were available from which 233 unique cases could be identified. Information on pregnancy outcome was available in only 137/233 cases (58.8 %): 67 live births (48.9 %); 31 miscarriages (22.6 %); 39 elective pregnancy terminations (28.5 %). In 93 cases (39.9 %) no outcome data were available (including 3 cases of ongoing pregnancy). Of the 137 pregnancies with reported outcomes, seven showed abnormalities (5.1 %) of which three (2.2 %) could potentially be interpreted as embryopathy: live birth with facial dysmorphism; miscarriage in week 10 with limb abnormality; elective pregnancy termination due to a foetal cardiac defect in a woman who had to terminate a previous pregnancy due to Fallot tetralogy. Within its limitations (small numbers, incomplete outcome data) our results do not indicate that DOAC exposure in pregnancy carries a high risk of embryopathy or that DOAC exposure per se should be used to direct patient counselling towards pregnancy termination. Pregnancy outcome data are inconsistently captured in pharmacovigilance databases indicating the strong need for a more robust system of reporting.

Warfarin-Associated Diaphragmatic Hernia: An Unusual Diagnosis

Fetal warfarin syndrome is a consequence of maternal intake of warfarin during pregnancy and comprises a wide range of manifestations, including some typical facial dysmorphologic features. The authors report a case of prenatal ultrasonographic diagnosis of warfarin embryopathy in an obese woman on unsupervised warfarin prophylaxis at the 16th week of gestation. The fetus presented with facial dysmorphism, pectus excavatum, diaphragmatic hernia, and pulmonary hypoplasia. To the best of our knowledge, this is the second reported case of warfarin-associated diaphragmatic hernia.

Importance of a multidisciplinary approach and monitoring in fetal warfarin syndrome

Warfarin is a synthetic oral anticoagulant that crosses the placenta and can lead to a number of congenital abnormalities known as fetal warfarin syndrome. Our aim is to report on the follow-up from birth to age 8 years of a patient with fetal warfarin syndrome. He presented significant respiratory dysfunction, as well as dental and speech and language complications. The patient was the second child of a mother who took warfarin during pregnancy due to a metallic heart valve. The patient had respiratory dysfunction at birth. On physical examination, he had a hypoplastic nose, pectus excavatum, and clubbing of the fingers. Nasal fibrobronchoscopy showed upper airway obstruction due to narrowing of the nasal cavities. He underwent surgical correction with Max Pereira graft, zetaplasty, and osteotomies for the piriform aperture. At dental evaluation, he had caries and delayed eruption of the upper incisors. Speech and language assessment revealed high palate, mouth breathing, little nasal patency, and shortened upper lip. Auditory long latency and cognitive-related potential to auditory stimuli demonstrated functional changes in the cortical auditory pathways. We believe that the frequency of certain findings observed in our patient may be higher in fetal warfarin syndrome than is appreciated, since a significant number result in abortions, stillbirths, or children evaluated in the first year of life without a follow-up. Thus, a multidisciplinary approach and long-term monitoring of these patients may be necessary.

Warfarin, a potential pollutant in aquatic environment acting through Pxr signaling pathway and γ-glutamyl carboxylation of vitamin K-dependent proteins

Warfarin-induced vitamin K (VK) recycling impairment is used worldwide as a rodenticide and human thromboembolic prophylactic. Since VK metabolism/signaling pathways have been conserved throughout vertebrate evolution, its release to the environment might impact on aquatic organisms. Present study assessed the toxic effect of warfarin (0, 5, 25 and 125 mg L(-1)) on zebrafish development and characterized underlying mechanisms of action through qPCR analysis of VK-related genes. Expression of pregnane X receptor (pxr), the nuclear receptor binding vitamin K, was ubiquitous in zebrafish and suggests that warfarin exposure may interfere with several biological processes. Indeed, warfarin exposure of zebrafish larvae caused hemorrhages in brain, skeletal deformities and triggered ectopic calcifications, which may be the consequence of an altered γ-carboxylation of VK-dependent proteins and/or pxr signaling. This study provides new insights into warfarin effects as a bone homeostasis disruptor and soft tissue calcification inductor, and its potential risk for aquatic environments.

Acute revascularization therapy in pregnant patients

Ischemic stroke is uncommon during pregnancy, but decision making for acute revascularization therapy including intravenous recombinant tissue plasminogen activator (rt-PA) is difficult. The use of rt-PA remains controversial, but a systematic review of 16 patients (mean age 31.7 years) showed good results for both maternal (77.8%) and fetal (56.3%) outcomes. Pregnancy alone is not a solid contraindication for acute revascularization therapy including rt-PA. An endovascular approach might be beneficial for reducing the hemorrhagic complication; however, the treatment strategy should be considered based on the available treatment facility. Close cooperation with obstetrics is essential for the successful management of saving the lives of both the mother and the fetus.

Congenital heart disease in pregnancy

The story of congenital heart disease is one of the major successes of medicine in the last 50 years. Heart conditions previously associated with early death are now successfully treated. Many of these women are now in their child-bearing years wishing to have children of their own. All of these women should be offered comprehensive pre-conception counselling by a dedicated multi-disciplinary team. Each woman will present a unique set of cardiac and obstetric challenges that require an individualised assessment of risk and a carefully documented care plan. In this chapter, I describe the most common forms of congenital heart disease and the specific issues that should be assessed before conception. I present a systematic approach to risk stratification and care planning. These lesions range from mild disease with little implications for pregnancy to those with a sizable risk of maternal mortality or complications. I will also discuss fetal risk factors.

Treating Cardiac Disease in Pregnancy

Maternal cardiac disease is a very significant cause of both maternal morbidity and mortality in westernized countries. An effective treatment program must tackle all of the contributing components, including those due to public health issues, poorly coordinated healthcare systems and inadequate medical education. Even with optimal care, many of these patients remain at high risk. In this setting, it is the role of the multidisciplinary team to counsel women regarding these risks and to proactively institute treatment algorithms that will optimize maternal and fetal outcomes.

Warfarin embryopathy: fetal manifestations

During the period 1991-2007, autopsy was undertaken in 13 fetuses with warfarin embryopathy. Pregnancy data and radiographic babygrams were available in each instance. Gestational age ranged from 17 to 37 weeks. Eleven of the fetuses had the characteristic nasal hypoplasia, but only three had radiological epiphyseal stippling. Cerebral hemorrhage was a major feature of autopsy in 8 of the fetuses, and it is evident that bleeding is a significant factor in the pathogenesis of warfarin embryopathy. A wide variety of additional visceral manifestations which were observed at autopsy have been tabulated. There was no obvious correlation between maternal or gestational age and the presence and severity of any specific embryopathic feature. No information was available concerning the dose and timing of warfarin administration in this series.

HEPARIN IN HUMAN PLACENTAL DEVELOPMENT AND THE PREVENTION OF PLACENTAL COMPLICATIONS OF PREGNANCY

The development of effective anticoagulant drugs available for use in pregnancy has resulted in dramatic improvements for a number of potentially life-threatening conditions. These include the treatment and prevention of venous thromboembolism and the thrombotic complications of antiphospholipid antibody syndrome, as well as the management of pregnant women with mechanical heart valves. The most commonly used class of drug includes heparin, a highly-charged macro-molecule that does not cross the placenta, in contrast to the potentially teratogenic and fetotoxic oral drug warfarin. This review will focus on our current lack of understanding of the wider actions of heparin and examines the possibility that large numbers of pregnant women are presently being treated inappropriately with heparin.