The placenta in stillbirth

Value of Placental Examination in the Diagnostic Evaluation of Stillbirth

ObjectiveThe aim was to assess the contribution of placental examination in the etiologic investigation of stillbirth. Materials and Methods: A retrospective review of stillbirths that occurred after 14 weeks gestation was conducted for a one-year period. Twin pregnancies and fetuses without placentas were excluded. According to the fetoplacental examination, stillbirths were classified into etiologic groups. Results: A total of 147 stillbirths were selected. They were associated with placental, materno-fetal, fetal and multiple causes in 89 cases (61%), 23 cases (16%), 14 cases (9%) and 13 cases (9%), respectively. Unexplained stillbirths were observed in 8 cases (5%). Placental abnormalities were identified in 132/147 cases (90%). They were consistent with vascular, inflammatory and developmental lesions in 82/132 cases (61%), 28/132 cases (21%) and 18/132 cases (13%), respectively. Conclusion: Placental lesions were the main causes of stillbirth and were predominantly of vascular type including chronic villous hypoxia-ischemia and funicular anomalies.

HIV, Placental Lesions, and Adverse Perinatal Outcomes

Africa has the highest number of pregnant women with human immunodeficiency virus (HIV). In some studies, HIV has been associated with adverse perinatal outcomes. However, the pathophysiological mechanism leading to adverse fetal outcomes is not known. Maternal vascular malformation, chorioamnionitis, and decreased placental weight have been described as placental features associated with HIV in some studies. The use of antiretroviral therapy has reduced perinatal transmission of HIV and adverse fetal outcomes. However, placental mechanisms associated with HIV and the fetal immune response to maternal HIV infection are poorly understood. Additional research is required to understand whether altered maternal immunity in women living with HIV can trigger fetal responses leading to stillbirth or preterm birth.

Placenta in intrauterine fetal demise (IUFD): a comprehensive study from a tertiary care hospital

Background: Intrauterine fetal demise (IUFD) is an unpredictable and challenging obstetric complication. Its etiology is multifactorial with more than 60% attributed to the placental cause. The present study was done with a primary objective of understanding the placental lesions underlying IUFD. Methods: In this retrospective observational study, IUFD cases (>22 weeks) between January 2012 and September 2015 were collected from pathology database. The clinical details with ultrasound findings were collected from mother's charts. The lesions were classified into (A) maternal vascular malperfusion (MVM) including retroplacental hematomas, (B) fetal vascular malperfusion (FVM), (C) inflammatory lesions, and (D) idiopathic. The contributor to fetal death was classified as direct, major, minor, unlikely, or unknown. Placental findings of fetal hypoxia were recorded. Results: The study included 100 cases of IUFD. The mean maternal age was 26 years (18-36 years). Primipara were 46. There were 65 early preterm (PT) (<34 weeks), 20 late PT (34 weeks to <37 weeks) and 15 term (>37 weeks) IUFD. The mean gestation age was 30 weeks. The ratio of male:female fetuses was 1:1.7. Relevant obstetric complications included preeclampsia (n = 39), intrauterine growth restriction (IUGR) (n = 7), pre-gestational diabetes (n = 7), bad obstetric history (n = 6), oligohydramnios (n = 5). The mean placental weight was 256 g. Maternal vascular malperfusion had the highest incidence (30%), followed by combined maternal and FVM (10%). Exclusive inflammatory lesions and FVM were seen in 12 and 6%, respectively. No cause was identified in 18%. Direct contributor to IUFD was identified in 51 cases and major, minor, unlikely contribution in 21, 11 and nine cases, respectively. In nine cases, it was unknown. Lesions indicating fetal hypoxia were noted in 35 cases. In both early and late PT, MVM featured more commonly (23 and 5%). In term placentas, the most common cause was idiopathic. Conclusions: Lesions of MVM were the most common cause of IUFD and served as a direct contributor to fetal demise.

Causes of stillbirth in a socioeconomically disadvantaged urban Australian population - a comprehensive analysis

INTRODUCTION

The aim of this paper was to provide an in-depth analysis of all stillbirth causation over a period of 10 years in a busy maternity unit located in a socioeconomically disadvantaged urban area, with an emphasis on overlapping pathology.

MATERIALS AND METHODS

A retrospective analysis of all structurally normal stillbirths in singleton pregnancies born during 2002-2012. The PSANZ stillbirth classification was used; per stillbirth subgroup main risk factors were evaluated.

RESULTS

Out of 130 cases, 43% showed overlapping pathologies. In the remaining 74 (56%) cases, the following single pathologies were found: IUGR 20 (15%), infection 12 (9%), abruption 8 (6%), placental thrombotic pathology 8 (6%), miscellaneous 6 stillbirths (5%), and 20 cases (15%) unexplained. Smoking was a risk factor for stillbirth associated with abruption (OR 3.639), infection (OR 2.271), and thrombotic pathology (OR 2.168). Drug use had an association with (placental) infection (OR 3.598). Obesity showed a significant association with IUGR (OR 3.782) and abruption (OR 9.040). Thrombophilia risk analysis for the overall group of stillbirths showed significant results for Protein S (OR 8.889) and homocysteine >90th centile (OR 2.087).

CONCLUSIONS

Overlapping pathology was identified in 43% of stillbirths. Infection, IUGR, and abruption were the most important single cause of stillbirth.

The preterm birth syndrome: issues to consider in creating a classification system

A comprehensive classification system for preterm birth requires expanded gestational boundaries that recognize the early origins of preterm parturition and emphasize fetal maturity over fetal age. Exclusion of stillbirths, pregnancy terminations, and multifetal gestations prevents comprehensive consideration of the potential causes and presentations of preterm birth. Any step in parturition (cervical softening and ripening, decidual-membrane activation, and/or myometrial contractions) may initiate preterm parturition, and should be recorded for every preterm birth, as should the condition of the mother, fetus, newborn, and placenta, before a phenotype is assigned.

Human cytomegalovirus infection is detected frequently in stillbirths and is associated with fetal thrombotic vasculopathy

BACKGROUND

Human cytomegalovirus (CMV) is the most common congenital infection in developed countries and is a known cause of intrauterine fetal death. We examined CMV infection in stillbirths and the relationship with histopathological findings at autopsy.

METHODS

We collected liver, kidney, and placenta specimens from 130 stillbirths. CMV DNA and protein were detected using polymerase chain reaction and immunohistochemistry, along with routine autopsy of stillborn infants.

RESULTS

Overall, CMV DNA was detected in 15% of singleton, >20-week stillborn infants. CMV DNA was detected in kidney (9%), liver (11%), and placenta (5%) specimens, with 75% of infections confirmed by immunohistochemistry. Fetal thrombotic vasculopathy was the only histopathological abnormality associated with CMV infection (in 60% CMV-infected vs 28% uninfected stillbirths P = .010).

CONCLUSIONS

Stillbirth has multiple etiologies. However, the detection of CMV DNA in 15% of fetal tissues or placentae suggests a strong association between CMV infection in pregnancy and stillbirth. Molecular testing during postmortem investigation has an important role to determine the contribution of CMV infection.

Stillbirths: the way forward in high-income countries

Stillbirth rates in high-income countries declined dramatically from about 1940, but this decline has slowed or stalled over recent times. The present variation in stillbirth rates across and within high-income countries indicates that further reduction in stillbirth is possible. Large disparities (linked to disadvantage such as poverty) in stillbirth rates need to be addressed by providing more educational opportunities and improving living conditions for women. Placental pathologies and infection associated with preterm birth are linked to a substantial proportion of stillbirths. The proportion of unexplained stillbirths associated with under investigation continues to impede efforts in stillbirth prevention. Overweight, obesity, and smoking are important modifiable risk factors for stillbirth, and advanced maternal age is also an increasingly prevalent risk factor. Intensified efforts are needed to ameliorate the effects of these factors on stillbirth rates. Culturally appropriate preconception care and quality antenatal care that is accessible to all women has the potential to reduce stillbirth rates in high-income countries. Implementation of national perinatal mortality audit programmes aimed at improving the quality of care could substantially reduce stillbirths. Better data on numbers and causes of stillbirth are needed, and international consensus on definition and classification related to stillbirth is a priority. All parents should be offered a thorough investigation including a high-quality autopsy and placental histopathology. Parent organisations are powerful change agents and could have an important role in raising awareness to prevent stillbirth. Future research must focus on screening and interventions to reduce antepartum stillbirth as a result of placental dysfunction. Identification of ways to reduce maternal overweight and obesity is a high priority for high-income countries.