Fleurisca J. Korteweg

The Tulip classification of perinatal mortality: introduction and multidisciplinary inter-rater agreement

Objective  To introduce the pathophysiological Tulip classification system for underlying cause and mechanism of perinatal mortality based on clinical and pathological findings for the purpose of counselling and prevention.

Diverse placental pathologies as the main causes of fetal death.

OBJECTIVE: To estimate the occurrence of placental causes of fetal death in relation to different gestational ages and their clinical manifestations during pregnancy. METHODS: In a prospective cohort study conducted from 2002 to 2006, we studied 750 couples with singleton intrauterine fetal death after 20 weeks of gestation. Cause of death was classified according to the Dutch Tulip cause of death classification for perinatal mortality. Differences between groups for categorical data were evaluated by the Fisher exact test or &khgr;2 test. RESULTS: The main causes were placental pathology (64.9%), congenital anomaly (5.3%), infection (1.9%), other (4.8%), and unknown (23.1%). The contribution of causes differed over gestational age periods. At lower gestational age, placental and unknown were the most dominant causes of death (34.8% and 41.7%, respectively); at higher gestational age, the relative importance of an unknown cause decreased and a placental cause increased (16.5% and 77.6%) (P<.001). Placental bed pathology was observed in 33.6% of all fetal deaths, with the highest occurrence between 24 0/7 and 31 6/7 weeks and a strong decline after 32 weeks. In contrast, contribution of developmental placental pathology (17.6%) increased after 32 weeks of gestation (P<.001), as did umbilical cord complications (5.2%) and combined placental pathology (5.4%). Solitary placental parenchyma pathology was less frequent (3.1%). Hypertension-related disease was observed in 16.1% (95% confidence interval [CI] 13.6–19.0) of the cohort, small for gestational age fetuses in 37.9% (95% CI 34.1–41.7), and diabetes-related disease in 4.1% (95% CI 2.8–5.8). CONCLUSION: Most fetal deaths were caused by a variety of placental pathologies. These were related to gestational age, and their clinical manifestations varied during pregnancy. LEVEL OF EVIDENCE: II

Cytogenetic analysis after evaluation of 750 fetal deaths: proposal for diagnostic workup

OBJECTIVE: To estimate success rates for cytogenetic analysis in different tissues after intrauterine fetal death, and study selection criteria and value of cytogenetic testing in determining cause of death. METHODS: Cytogenetic analyses and the value of this test in determining cause by a multidisciplinary panel were studied in 750 fetal deaths. Morphologic abnormalities, small for gestational age (SGA), advanced maternal age (older than 35 years) and maceration were studied as selection criteria. RESULTS: Chromosomal abnormalities were observed in 13% of fetal deaths. Cytogenetic success rates were significantly higher for invasive testing (85%) than for postpartum tissue analysis (28%, P<.001). There were more abnormal chromosomes (38%) in fetal deaths with morphologic abnormalities than in those without (5%, P<.001). This was not observed for SGA (16% compared with 9.2%, P=.22) or for advanced maternal age (16.7% compared with 12.0%, P=.37). The posterior probability of a chromosomal abnormality in the absence of morphologic abnormalities was still 4.6%. Cytogenetic analysis was successful in 35% of severely macerated fetuses. We do not advise using these selection criteria, because the failure rate was high on postpartum tissues. Cytogenetic analysis was valuable in determining the cause in 19% of the fetal deaths. CONCLUSION: Parents should be counseled on aspects of cytogenetic analysis after fetal death. We advise performing nonselective invasive testing after fetal death and before labor for all fetal deaths. LEVEL OF EVIDENCE: II

Reduction of high fetal loss rate by anticoagulant treatment during pregnancy in antithrombin, protein C or protein S deficient women

Hereditary thrombophilia is associated with an increased risk of fetal loss. Assuming that fetal loss is due to placental thrombosis, anticoagulant treatment might improve pregnancy outcome. In an observational family cohort study, we prospectively assessed the effects of anticoagulant drugs on fetal loss rates in women with hereditary deficiencies of antithrombin, protein C or protein S. The cohort contained 376 women (50 probands and 326 deficient or non‐deficient relatives). Probands were consecutive deficient patients with venous tromboembolism. Thromboprophylaxis during pregnancy was recommended in deficient women, irrespective of prior venous thromboembolism, and in non‐deficient women with prior venous thromboembolism. Outcome of first pregnancy was analysed in 55 eligible women. Of 37 deficient women, 26 (70%) received thromboprophylaxis during pregnancy, compared with three of 18 (17%) non‐deficient women. Fetal loss rates were 0% in deficient women with thromboprophylaxis versus 45% in deficient women without (P = 0·001) and 7% in non‐deficient women without thromboprophylaxis (P = 0·37). The adjusted relative risk of fetal loss in women who received thromboprophylaxis versus women who did not was 0·07 (95% confidence interval 0·001–0·7; P = 0·02). Our data suggest that anticoagulant treatment during pregnancy reduces the high fetal loss rate in women with hereditary deficiencies of antithrombin, protein C or protein S.

High risk of pregnancy-related venous thromboembolism in women with multiple thrombophilic defects

Pregnancy is associated with an increased risk of venous thromboembolism, which probably varies according to the presence of single or multiple thrombophilic defects. This retrospective family cohort study assessed the risk of venous thromboembolism during pregnancy and puerperium, and the contribution of concomitant thrombophilic defects in families with hereditary antithrombin, protein C or protein S deficiencies. Probands were excluded. Of 222 female relatives, 101 were deficient and 121 non‐deficient. Annual incidences of venous thromboembolism were 1·76% in deficient women versus 0·19% in non‐deficient women [adjusted relative risk (RR) 11·9; 95% confidence interval (CI), 3·9–36·2]. Other single and multiple thrombophilic defects increased the risk in deficient women from 1·55% to 2·14% and 2·92%, and in non‐deficient women from 0·16% to 0·09% and 0·54% respectively. Deficient women were at lower risk (1·37%; 0·80–2·19) than deficient women that had never been pregnant (2·96%; 1·53–5·18); RR 0·5 (0·2–0·99). This difference was due to the predominance of events related to oral contraceptives in deficient women that had never been pregnant (75%), while 71% of events in deficient women that had had at least one pregnancy were pregnancy‐related. In conclusion, women with hereditary deficiencies of antithrombin, protein C or protein S are at high risk of pregnancy‐related venous thromboembolism. This risk is increased by multiple additional thrombophilic defects.

Seeking order amidst chaos: A systematic review of classification systems for causes of stillbirth and neonatal death, 2009-2014

BackgroundEach year, about 5.3 million babies die in the perinatal period. Understanding of causes of death is critical for prevention, yet there is no globally acceptable classification system. Instead, many disparate systems have been developed and used. We aimed to identify all systems used or created between 2009 and 2014, with their key features, including extent of alignment with the International Classification of Diseases (ICD) and variation in features by region, to inform the World Health Organization’s development of a new global approach to classifying perinatal deaths.MethodsA systematic literature review (CINAHL, EMBASE, Medline, Global Health, and PubMed) identified published and unpublished studies and national reports describing new classification systems or modifications of existing systems for causes of perinatal death, or that used or tested such systems, between 2009 and 2014. Studies reporting ICD use only were excluded. Data were independently double-extracted (except from non-English publications). Subgroup analyses explored variation by extent and region.ResultsEighty-one systems were identified as new, modifications of existing systems, or having been used between 2009 and 2014, with an average of ten systems created/modified each year. Systems had widely varying characteristics: (i) comprehensiveness (40 systems classified both stillbirths and neonatal deaths); (ii) extent of use (systems were created in 28 countries and used in 40; 17 were created for national use; 27 were widely used); (iii) accessibility (three systems available in e-format); (iv) underlying cause of death (64 systems required a single cause of death); (v) reliability (10 systems tested for reliability, with overall Kappa scores ranging from .35–.93); and (vi) ICD alignment (17 systems used ICD codes). Regional databases were not searched, so system numbers may be underestimated. Some non-differential misclassification of systems was possible.ConclusionsThe plethora of systems in use, and continuing system development, hamper international efforts to improve understanding of causes of death. Recognition of the features of currently used systems, combined with a better understanding of the drivers of continued system creation, may help the development of a truly effective global system.

Characteristics of a global classification system for perinatal deaths: a Delphi consensus study

BackgroundDespite the global burden of perinatal deaths, there is currently no single, globally-acceptable classification system for perinatal deaths. Instead, multiple, disparate systems are in use world-wide. This inconsistency hinders accurate estimates of causes of death and impedes effective prevention strategies. The World Health Organisation (WHO) is developing a globally-acceptable classification approach for perinatal deaths. To inform this work, we sought to establish a consensus on the important characteristics of such a system.MethodsA group of international experts in the classification of perinatal deaths were identified and invited to join an expert panel to develop a list of important characteristics of a quality global classification system for perinatal death. A Delphi consensus methodology was used to reach agreement. Three rounds of consultation were undertaken using a purpose built on-line survey. Round one sought suggested characteristics for subsequent scoring and selection in rounds two and three.ResultsThe panel of experts agreed on a total of 17 important characteristics for a globally-acceptable perinatal death classification system. Of these, 10 relate to the structural design of the system and 7 relate to the functional aspects and use of the system.ConclusionThis study serves as formative work towards the development of a globally-acceptable approach for the classification of the causes of perinatal deaths. The list of functional and structural characteristics identified should be taken into consideration when designing and developing such a system.

Thrombin activatable fibrinolysis inhibitor (TAFI) is not associated with fetal loss, a retrospective study

a Division of Haemostasis, Thrombosis and Rheology, University Medical Centre Groningen, The Netherlands b Department of Obstetrics and Gynaecology, University Medical Centre Groningen, The Netherlands c Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands d Department of Hematology, University Hospital Maastricht, Maastricht, The Netherlands e Department of Clinical Epidemiology and Medical Technology Assessment, University Hospital Maastricht, Maastricht, The Netherlands

Subsequent pregnancy outcome after previous foetal death

OBJECTIVE A history of foetal death is a risk factor for complications and foetal death in subsequent pregnancies as most previous risk factors remain present and an underlying cause of death may recur. The purpose of this study was to evaluate subsequent pregnancy outcome after foetal death and to compare cases of recurrent foetal death. STUDY DESIGN A retrospective cohort study in a tertiary referral centre. All women with a stillbirth beyond 16 weeks of gestation between January 1999 and December 2004 (n=193) were identified. After providing informed consent, the medical records of 163 women were reviewed until August 2006 in terms of clinical, medical, obstetric and paediatric data of the pregnancy after the index pregnancy that resulted in foetal death. The cause of death for reported cases of foetal death and recurrent foetal death were classified by a multidisciplinary team according to the Tulip classification. RESULTS Recurrent foetal death occurred in 11 cases, and various causes were identified. The cause of death was explained in seven cases. An association was found between the index foetal death and subsequent foetal death in some cases, especially in early gestation. CONCLUSIONS This study illustrates the importance of classifying the cause of recurrent foetal death and contributing risk factors using the same classification system. This provides more insight into the pathophysiological pathways leading to foetal death, and enables meaningful comparisons to be made in recurrent foetal death. This is required before preventive strategies can be instituted and implemented to reduce the risk of foetal death.

Making stillbirths visible: a systematic review of globally reported causes of stillbirth

Stillbirth is a global health problem. The World Health Organization (WHO) application of the International Classification of Diseases for perinatal mortality (ICD‐PM) aims to improve data on stillbirth to enable prevention.