Methodology to Determine Cause of Death for Stillbirths and Neonatal Deaths Using Automated Case Reports and a Cause-of-Death Panel

Pregnancy outcomes in preterm multiple gestations: Results from a prospective study in India and Pakistan (PURPOSe)

OBJECTIVE

To evaluate perinatal outcomes in preterm multiple compared with singleton pregnancies in India and Pakistan.

DESIGN

Prospective, observational study.

SETTINGS

Study hospitals in India and Pakistan.

POPULATION

We evaluated 3897 preterm pregnancies. These mothers gave birth to 3615 (92.8%) singleton infants, 267 (6.8%) sets of twins, 14 (0.4%) sets of triplets and one set of quadruplets.

MAIN OUTCOME MEASURES

Neonatal mortality, stillbirth, cause of death.

RESULTS

Of the singleton infants, 691 (19.1%) were stillborn and 2924 (80.9%) live born. Of the 534 infants from twin pregnancies, 41 (7.7%) were stillborn and 493 (92.3%) were live born. Of the 267 sets of twins, in 14 cases (5.2%) both were stillborn, in 13 cases (4.8%) one was stillborn and one live born, and in 240 cases (90.0%) both were live born. In both preterm twins and preterm singletons, the three most common causes of death were intrauterine hypoxia, infections acquired prior to birth and infections acquired at or after birth. The preterm twins appeared less likely to have died from intrauterine hypoxia but more likely to have died from infections acquired at or after birth. Respiratory distress syndrome (RDS) was less likely considered by the panel to be the primary cause of death in either the twins (9.6%) or singletons (9.7%). Congenital anomalies were also not often judged to be the cause of death in either the preterm twins 2 (2.4%) or singletons 27 (5.3%).

CONCLUSION

In the PURPOSe study, neonatal mortality rates in preterm twins compared with singletons when evaluated by sex, GA, birthweight and SGA, were generally similar to rates of preterm singleton neonatal mortality in those groups. Thus, the higher rate of mortality in live-born twin infants is related to the fact that these infants were more likely to be born earlier rather than to any inherent characteristics of the babies themselves.

The PURPOSe cause of death study in stillbirths and neonatal deaths in India and Pakistan: A review

The PURPOSe study was a prospective, observational study conducted in India and Pakistan to determine the cause of death for stillbirths and preterm neonatal deaths, using clinical data together with minimally invasive tissue sampling (MITS) and the histologic and polymerase chain reaction (PCR) evaluation of fetal/neonatal tissues and the placenta. After evaluating all available data, an independent panel chose a maternal, a placental and a fetal/neonatal cause of death. Here, we summarise the major results. Among the most important findings were that most stillbirths were caused by fetal asphyxia, often preceded by placental malperfusion, and clinically associated with pre-eclampsia, placental abruption and a small-for-gestational-age fetus. The preterm neonatal deaths were primarily caused by birth asphyxia, followed by various infections. An important finding was that many of the preterm neonatal deaths were caused by a nosocomial infection acquired after neonatal intensive care (NICU) admission; the most common organisms were Acinetobacter baumannii, followed by Klebsiella pneumoniae, Escherichia coli/Shigella and Haemophilus influenzae. Group B streptococcus was less commonly present in the placentas or internal organs of the neonatal deaths.

Data usefulness in determining cause of stillbirth in South Asia

OBJECTIVE

To evaluate the usefulness of data to determine cause of stillbirth in India and Pakistan.

DESIGN

Prospective, observational study.

SETTINGS

Study hospitals in India and Pakistan.

POPULATION

200 fetal deaths with placental evaluation and minimally invasive tissue sampling (MITS) of internal organs and polymerase chain reaction (PCR) test for 75 pathogens.

MAIN OUTCOME MEASURES

Data defined as useful to determine stillbirth causes.

RESULTS

Placental pathology was the most useful to determine cause of stillbirth. Comparing placental and fetal weight with standard weights was useful in 44.5% and 48.5%, respectively. Lung histology was useful in 42.5%. Most of the other findings of internal organ histology were only occasionally useful. Signs of abruption, by maternal history or placental evaluation, were always deemed useful. Placenta, brain and cord blood PCR were also useful, but less often than histology.

CONCLUSION

Based on this analysis, maternal clinical history, placental histology and fetal examination were most informative. Comparing the placental and fetal weights with recognised standards was useful in nearly half the cases. Fetal tissue histology and PCR were also informative. Of all the potential tests of MITS-obtained specimens, we would first recommend histological evaluation of the lungs, and using a multiplex PCR platform would determine pathogens in blood and brain/CSF. We recognise that this approach will not identify some causes, including some genetic and internal organ anomalies, but will confirm most common causes of stillbirth and most of the preventable causes of stillbirth in low- and middle-income countries.

An approach to determining the most common causes of stillbirth in low and middle-income countries: A commentary

Stillbirth, one of the most common adverse pregnancy outcomes, is especially prevalent in low and middle-income countries (LMICs). Understanding the causes of stillbirth is crucial to developing effective interventions. In this commentary, investigators working across several LMICs discuss the most useful investigations to determine causes of stillbirths in LMICs. Useful data were defined as 1) feasible to obtain accurately and 2) informative to determine or help eliminate a cause of death. Recently, new tools for LMIC settings to determine cause of death in stillbirths, including minimally invasive tissue sampling (MITS) - a method using needle biopsies to obtain internal organ tissue from deceased fetuses for histology and pathogen identification in those tissues have become available. While placental histology has been available for some time, the development of the Amsterdam Criteria in 2016 has provided a useful framework to categorize placental lesions. The authors recommend focusing on the clinical history, the placental evaluation, the external examination of the fetus, and, when available, fetal tissue obtained by MITS, especially of the lung (focused on histology and microbiology) and brain/cerebral spinal fluid (CSF) and fetal blood (focused on microbiological analysis). The authors recognize that this approach may not identify some causes of stillbirth, including some genetic abnormalities and internal organ anomalies, but believe it will identify the most common causes of stillbirth, and most of the preventable causes.

The causes of preterm neonatal deaths in India and Pakistan (PURPOSe): a prospective cohort study

BACKGROUND

Preterm birth remains the major cause of neonatal death worldwide. South Asia contributes disproportionately to deaths among preterm births worldwide, yet few population-based studies have assessed the underlying causes of deaths. Novel evaluations, including histological and bacteriological assessments of placental and fetal tissues, facilitate more precise determination of the underlying causes of preterm deaths. We sought to assess underlying and contributing causes of preterm neonatal deaths in India and Pakistan.

METHODS

The project to understand and research preterm pregnancy outcomes and stillbirths in South Asia (PURPOSe) was a prospective cohort study done in three hospitals in Davangere, India, and two hospitals in Karachi, Pakistan. All pregnant females older than 14 years were screened at the time of presentation for delivery, and those with an expected or known preterm birth, defined as less than 37 weeks of gestation, were enrolled. Liveborn neonates with a weight of 1000 g or more who died by 28 days after birth were included in analyses. Placentas were collected and histologically evaluated. In addition, among all neonatal deaths, with consent, minimally invasive tissue sampling was performed for histological analyses. PCR testing was performed to assess microbial pathogens in the placental, blood, and fetal tissues collected. An independent panel reviewed available data, including clinical description of the case and all clinical maternal, fetal, and placental findings, and results of PCR bacteriological investigation and minimally invasive tissue sampling histology, from all eligible preterm neonates to determine the primary and contributing maternal, placental, and neonatal causes of death.

FINDINGS

Between July 1, 2018, and March 26, 2020, of the 3470 preterm neonates enrolled, 804 (23%) died by 28 days after birth, and, of those, 615 were eligible and had their cases reviewed by the panel. Primary maternal causes of neonatal death were hypertensive disease (204 [33%] of 615 cases), followed by maternal complication of pregnancy (76 [12%]) and preterm labour (76 [11%]), whereas the primary placental causes were maternal and fetal vascular malperfusion (172 [28%] of 615) and chorioamnionitis, funisitis, or both (149 [26%]). The primary neonatal cause of death was intrauterine hypoxia (212 [34%] of 615) followed by congenital infections (126 [20%]), neonatal infections (122 [20%]), and respiratory distress syndrome (126 [20%]).

INTERPRETATION

In south Asia, intrauterine hypoxia and congenital infections were the major causes of neonatal death among preterm babies. Maternal hypertensive disorders and placental disorders, especially maternal and fetal vascular malperfusion and placental abruption, substantially contributed to these deaths.

FUNDING

Bill & Melinda Gates Foundation.

Birth asphyxia is under-rated as a cause of preterm neonatal mortality in low- and middle-income countries: A prospective, observational study from PURPOSe

OBJECTIVE

To assess respiratory distress syndrome (RDS) compared with birth asphyxia as the cause of death in preterm newborns, assigned by the neonatal intensive care unit (NICU) physician at the time of death and assigned by a panel with complete obstetric history, placental evaluation, tissue histology and microbiology.

DESIGN

Prospective, observational study.

SETTINGS

Study NICUs in India and Pakistan.

POPULATION

Preterm infants delivered in study facility.

METHODS

A total of 410 preterm infants who died in the NICU with cause of death ascertained by the NICU physicians and independently by expert panels. We compared the percentage of cases assigned RDS versus birth asphyxia as cause of death by the physician and the panel.

MAIN OUTCOME MEASURES

RDS and birth asphyxia.

RESULTS

Of 410 preterm neonatal deaths, the discharging NICU physicians found RDS as a cause of death among 83.2% of the cases, compared with the panel finding RDS in only 51.0%. In the same neonatal deaths, the NICU physicians found birth asphyxia as a cause of death in 14.9% of the deaths, whereas the panels found birth asphyxia in 57.6% of the deaths. The difference was greater in Pakistan were the physicians attributed 89.7% of the deaths to RDS and less than 1% to birth asphyxia whereas the panel attributed 35.6% of the deaths to RDS and 62.7% to birth asphyxia.

CONCLUSIONS

NICU physicians who reported cause of death in deceased preterm infants less often attributed the death to birth asphyxia, and instead more often chose RDS, whereas expert panels with more extensive data attributed a greater proportion of deaths to birth asphyxia than did the physicians.