Sudden intrauterine unexplained death: time to adopt uniform postmortem investigative guidelines?

Investigation of stillbirths in Brazil: A systematic scoping review of the causes and related reporting processes in the past decade

BACKGROUND

Recognizing the causes of stillbirths and their associated conditions is essential to reduce its occurrence.

OBJECTIVE

To describe information on stillbirths in Brazil during the past decade.

SEARCH STRATEGY

A literature search was performed from January 2010 to December 2020.

SELECTION CRITERIA

Original observational studies and clinical trials.

DATA COLLECTION AND ANALYSIS

Data were manually extracted to a spreadsheet and descriptive analysis was performed.

RESULTS

A total of 55 studies were included; 40 studies (72.2%) used the official data stored by national public health systems. Most articles aimed to estimate the rate and trends of stillbirth (60%) or their causes (55.4%). Among the 16 articles addressing the causes of death, 10 (62.5%) used the International Classification of Diseases; most of the articles only specified the main cause of death. Intrauterine hypoxia was the main cause reported (ranging from 14.3% to 54.9%).

CONCLUSION

Having a national system based on compulsory notification of stillbirths may not be sufficient to provide quality information on occurrence and, especially, causes of death. Further improvements of the attribution and registration of causes of deaths and the implementation of educational actions for improving reporting systems are advisable. Finally, expanding the investigation of contributing factors associated with stillbirths would create an opportunity for further development of prevention strategies in low- and middle-income countries such as Brazil.

Harmful Effect of Intrauterine Smoke Exposure on Neuronal Control of "Fetal Breathing System" in Stillbirths

This article is aimed to contribute to the current knowledge on the role of toxic substances such as nicotine on sudden intrauterine unexplained deaths’ (SIUDS’) pathogenetic mechanisms. The in-depth histopathological examination of the autonomic nervous system in wide groups of victims of SIUDS (47 cases) and controls (20 cases), with both smoking and no-smoking mothers, highlighted the frequent presence of the hypodevelopment of brainstem structures checking the vital functions. In particular, the hypoplasia of the pontine parafacial nucleus together with hypoplastic lungs for gestational age were observed in SIUDS cases with mothers who smoked cigarettes, including electronic ones. The results allow us to assume that the products of cigarette smoke during pregnancy can easily cross the placental barrier, thus entering the fetal circulation and damaging the most sensitive organs, such as lungs and brain. In a non-negligible percentage of SIUDS, the mothers did not smoke. Furthermore, based on previous and ongoing studies conducted through analytical procedures and the use of scanning electron microscopy, the authors envisage the involvement of toxic nanoparticles (such as agricultural pesticides and nanomaterials increasingly used in biomedicine, bioscience and biotechnology) in the death pathogenesis, with similar mechanisms to those of nicotine.

Investigation of stillbirth causes in Suriname: application of the WHO ICD-PM tool to national-level hospital data

Background

Suriname has one of the highest stillbirth rates in Latin America and the Caribbean. To facilitate data comparison of perinatal deaths, the World Health Organization developed the International Classification of Diseases-10 Perinatal Mortality (ICD-PM).

Objective

We aimed to (1) assess characteristics and risk indicators of women with a stillbirth, (2) determine the timing and causes of stillbirths according to the ICD-PM with critical evaluation of its application and (3) propose recommendations for the reduction of stillbirths in Suriname.

Methods

A hospital-based, nation-wide, cross-sectional study was conducted in all hospitals within Suriname during one-year (2017). The medical files of stillbirths (gestation ≥28 weeks/birth weight ≥1000 grams) were reviewed and classified using ICD-PM. We used descriptive statistics and multiple logistic regression analyses.

Results

The stillbirth rate in Suriname was 14.4/1000 births (n=131 stillbirths, n=9089 total births). Medical files were available for 86% (n=113/131) of stillbirths. Women of African descent had the highest stillbirth rate and two times the odds of stillbirth (OR 2.1, 95%CI 1.4–3.1) compared to women of other ethnicities. One third (33%, n=37/113) of stillbirths occurred after hospital admission. The timing was antepartum in 85% (n=96/113), intrapartum in 11% (n=12/113) and unknown in 4% (n=5/113). Antepartum stillbirths were caused by hypoxia in 46% (n=44/96). In 41% (n=39/96) the cause was unspecified. Maternal medical and surgical conditions were present in 50% (n=57/113), mostly hypertensive disorders.

Conclusion

Stillbirth reduction strategies in Suriname call for targeting ethnic disparities, improving antenatal services, implementing perinatal death audits and improving diagnostic post-mortem investigations. ICD-PM limited the formulation of recommendations due to many stillbirths of ‘unspecified’ causes. Based on our study findings, we also recommend addressing some challenges with applying the ICD-PM.

Abbreviations

CTG: Cardiotocography; ENAP: Every Newborn Action Plan (ENAP); ICD-PM: The WHO application of ICD-10 to deaths during the perinatal period – perinatal mortality; SBR: Stillbirth rate; SGA: Small for gestational age; WHO: World Health Organization; LMIC: Low- and middle-income countries; FHR: foetal heart rate.

Silver nanoparticles in the fetal brain: new perspectives in understanding the pathogenesis of unexplained stillbirths

We report, for the first time, the surprising presence of toxic nanoparticles, especially silver, in the brain of a fetus, who died unexpectedly at the end of a regular pregnancy. After an accurate autopsy, including the examination of the fetal annexes, an in-depth anatomopathological study of the nervous system and a search by scanning electron microscopy of nanoparticles in the brain, we highlighted the sequence of events that may have led to this fetal death, triggered primarily by the transition of nanosized xenobiotics from the mother to the fetal bloodstream. From this report emerges the importance of considering the search of nanosubstances in the brain during routine investigations following unexpected and unexplained fetal and infant deaths.

The Role of Maternal Smoking in Sudden Fetal and Infant Death Pathogenesis

Maternal smoking is a risk factor for both sudden infant death syndrome (SIDS) and sudden intrauterine unexplained death syndrome (SIUDS). Both SIDS and SIUDS are more frequently observed in infants of smoking mothers. The global prevalence of smoking during pregnancy is 1.7% and up to 8.1% of women in Europe smoke during pregnancy and worldwide 250 million women smoke during pregnancy. Infants born to mothers who smoke have an abnormal response to hypoxia and hypercarbia and they also have reduced arousal responses. The harmful effects of tobacco smoke are mainly mediated by release of carbon monoxide and nicotine. Nicotine can enter the fetal circulation and affect multiple developing organs including the lungs, adrenal glands and the brain. Abnormalities in brainstem nuclei crucial to respiratory control, the cerebral cortex and the autonomic nervous system have been demonstrated. In addition, hypodevelopment of the intermediolateral nucleus in the spinal cord has been reported. It initiates episodic respiratory movements that facilitate lung development. Furthermore, abnormal maturation and transmitter levels in the carotid bodies have been described which would make infants more vulnerable to hypoxic challenges. Unfortunately, smoking cessation programs do not appear to have significantly reduced the number of pregnant women who smoke.