Sara Twaddle

Thrombophilia in pregnancy: a systematic review

Growing evidence suggests that thrombophilia is associated with venous thromboembolism (VTE) and adverse pregnancy outcomes. However, methodological limitations have made it difficult to obtain a clear overview of the overall risks. We conducted a systematic review to determine the risk of VTE and adverse pregnancy outcomes associated with thrombophilia in pregnancy. The effectiveness of prophylactic interventions during pregnancy was also evaluated. Major electronic databases were searched, relevant data abstracted and study quality assessed by two independent reviewers. Odds ratios (ORs) stratified by thrombophilia type were calculated for each outcome. A total of 79 studies were included in our review. The risks for individual thrombophilic defects were determined for VTE (ORs, 0·74–34·40); early pregnancy loss (ORs, 1·40–6·25); late pregnancy loss (ORs, 1·31–20·09); pre‐eclampsia (ORs, 1·37–3·49); placental abruption (ORs, 1·42–7·71) and intrauterine growth restriction (ORs, 1·24–2·92). Low‐dose aspirin plus heparin was the most effective in preventing pregnancy loss in thrombophilic women (OR, 1·62). Our findings confirm that women with thrombophilia are at risk of developing VTE and complications in pregnancy. However, despite the increase in relative risk, the absolute risk of VTE and adverse outcomes remains low. There is also a lack of controlled trials of antithrombotic intervention to prevent pregnancy complications. Thus, at present, universal screening for thrombophilia in pregnancy cannot be justified clinically.

Randomised, controlled trial of efficacy of midwife-managed care

BACKGROUND Midwife-managed programmes of care are being widely implemented although there has been little investigation of their efficacy. We have compared midwife-managed care with shared care (ie, care divided among midwives, hospital doctors, and general practitioners) in terms of clinical efficacy and womens satisfaction. METHODS We carried out a randomised controlled trial of 1299 pregnant women who had no adverse characteristics at booking (consent rate 81.9%). 648 women were assigned midwife-managed care and 651 shared care. The research hypothesis was that compared with shared care, midwife-managed care would produce fewer interventions, similar (or more favourable) outcomes, similar complications, and greater satisfaction with care. Data were collected by retrospective review of case records and self-report questionnaires. Analysis was by intention to treat. FINDINGS Interventions were similar in the two groups or lower with midwife-managed care. For example, women in the midwife-managed group were less likely than women in shared care to have induction of labour (146 [23.9%] vs 199 [33.3%]; 95% CI for difference 4.4-14.5). Women in the midwife-managed group were more likely to have an intact perineum and less likely to have had an episiotomy (p = 0.02), with no significant difference in perineal tears. Complication rates were similar. Overall, 32.8% of women were permanently transferred from midwife-managed care (28.7% for clinical reasons, 3.7% for non-clinical reasons). Women in both groups reported satisfaction with their care but the midwife-managed group were significantly more satisfied with their antenatal (difference in mean scores 0.48 [95% CI 0.41-0.55]), intrapartum (0.28 [0.18-0.37]), hospital-based postnatal care (0.57 [0.45-0.70]), and home-based postnatal care (0.33 [0.25-0.42]). INTERPRETATION We conclude that midwife-managed care for healthy women, integrated within existing services, is clinically effective and enhances womens satisfaction with maternity care.

Oral contraceptives, hormone replacement therapy, thrombophilias and risk of venous thromboembolism: a systematic review The Thrombosis: Risk and Economic Assessment of Thrombophilia Screening (TREATS) Study

Combined oral contraceptives, oral hormone replacement therapy and thrombophilias are recognised risk factors for venous thromboembolism in women. The objective of this study was to assess the risk of thromboembolism among women with thrombophilia who are taking oral contraceptives or hormone replacement therapy, conducting a systematic review and metaanalysis. Of 201 studies identified, only nine met the inclusion criteria. Seven studies included pre-menopausal women on oral contraceptives and two studies included peri-menopausal women on hormone replacement therapy. For oral contraceptive use, significant associations of the risk of venous thromboembolism were found in women with factor V Leiden (OR 15.62; 95%CI 8.66 to 28.15); deficiencies of antithrombin (OR 12.60; 95%CI 1.37 to 115.79), protein C (OR 6.33; 95%CI 1.68 to 23.87), or protein S (OR 4.88; 95%CI 1.39 to 17.10), elevated levels of factor VIIIc (OR 8.80; 95%CI 4.13 to 18.75); and factor V Leiden and prothrombin G20210A (OR 7.85; 95%CI 1.65 to 37.41). For hormone replacement therapy, a significant association was found in women with factor V Leiden (OR 13.16; 95%CI 4.28 to 40.47). Although limited by the small number of studies, the findings of this study support the presence of interaction between thrombophilia and venous thromboembolism among women taking oral contraceptives. However, further studies are required to establish with greater confidence the associations of these, and other, thrombophilias with venous thromboembolism among hormone users.

Screening for thrombophilia in high-risk situations: a meta-analysis and cost-effectiveness analysis

Laboratory testing for the identification of heritable thrombophilia in high‐risk patient groups have become common practice; however, indiscriminate testing of all patients is unjustified. The objective of this study was to evaluate the cost‐effectiveness of universal and selective history‐based thrombophilia screening relative to no screening, from the perspective of the UK National Health Service, in women prior to prescribing combined oral contraceptives and hormone replacement therapy, women during pregnancy and patients prior to major orthopaedic surgery. A decision analysis model was developed, and data from meta‐analysis, the literature and two Delphi studies were incorporated in the model. Incremental cost‐effectiveness ratios (ICERs) for screening compared with no screening was calculated for each patient group. Of all the patient groups evaluated, universal screening of women prior to prescribing hormone replacement therapy was the most cost‐effective (ICER £6824). In contrast, universal screening of women prior to prescribing combined oral contraceptives was the least cost‐effective strategy (ICER £202 402). Selective thrombophilia screening based on previous personal and/or family history of venous thromboembolism was more cost‐effective than universal screening in all the patient groups evaluated.

An evaluation of economics and acceptability of screening for Chlamydia trachomatis infection, in women attending antenatal, abortion, colposcopy and family planning clinics in Scotland, UK

Objective  The aims of this study were to determine cost effectiveness of screening for Chlamydia trachomatis in hospital‐based antenatal and gynaecology clinics, and community‐based family planning clinics. Additionally, womens views of screening were determined in the hospital‐based clinics.

Moving towards a common understanding in maternity services

There is a need to ensure that there is a common understanding of what is meant by the terminology surrounding the organisation and provision of maternity services. This is especially important with the development of purchaser/provider contracts in the National Health Service (NHS) in the UK. It is vitally important that terms specified in contracts are not ambiguous. It is also important that practitioners and researchers are working from a common base. Information on local definitions used in Scottish health boards was obtained through questionnaires sent to Heads of Midwifery Services in consultant units. The findings show that for some terms the definitions were fairly standard, but for others there were considerable differences in how the terms were interpreted. In light of these differences, and given the necessity for clearly defined terms within the new NHS, professionally agreed definitions were produced by the Royal College of Midwives. It is recommended that these definitions be adopted as standard by relevant individuals and groups.