Joke M. Ravise

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