Unexplained Antepartum Death Research Articles

Prospective cohort study: Causes of stillbirth in Australia 2013-2018.

Stillbirth is a major public health problem that is slow to improve in Australia. Understanding the causes of stillbirth through appropriate investigation is the cornerstone of prevention and important for parents to understand why their baby died. The aim of this study is to assess compliance with the Perinatal Society of Australia and New Zealand (PSANZ) Perinatal Mortality Clinical Practice Guidelines (2009) for stillbirths. This is a prospective multi-centred cohort study of stillbirths at participating hospitals (2013-2018). Data were recorded into a purpose-built database. The frequency of the recommended core investigations was calculated, and χ2 test was performed for subgroup analyses by gestational age groups and timing of fetal death. A 70% compliance threshold was defined for investigations. The cause of death categories was provided according to PSANZ Perinatal Death Classification. Among 697 reported total stillbirths, 562 (81%) were antepartum, and 101 (15%) were intrapartum. The most common cause of death categories were 'congenital abnormality' (12.5%), 'specific perinatal conditions' (12.2%) and 'unexplained antepartum death' (29%). According to 2009 guidelines, there were no stillbirths where all recommended investigations were performed (including or excluding autopsy). A compliance of 70% was observed for comprehensive history (82%), full blood count (94%), cytomegalovirus (71%), toxoplasmosis (70%), renal function (75%), liver function (79%), external examination (86%), post-mortem examination (84%) and placental histopathology (92%). The overall autopsy rate was 52%. Compliance with recommended investigations for stillbirth was suboptimal, and many stillbirths remain unexplained. Education on the value of investigations for stillbirth is needed. Future studies should focus on understanding the yield and value of investigations and service delivery gaps that impact compliance.

A perinatal review of singleton stillbirths in an Australian metropolitan tertiary centre.

It is estimated that everyday 7000 women worldwide have their pregnancy end with a stillbirth, however, research and data collection on stillbirth remains underfunded. This stillbirth case series audit investigates an apparent rise in stillbirths at a Sydney tertiary referral hospital in Australia. A retrospective case series of singleton stillbirths from 2005–2010 was conducted at Westmead Hospital. Stillbirth was defined as per the Perinatal Society of Australia and New Zealand classification as a death of a baby before or during birth, from the 20th week of pregnancy onwards, or a birth weight of 400 grams or more if gestational age is unknown. A total of 215 singleton stillbirths were identified in a cohort of 28 109, a rate of 7.6 per 1000 singleton births. There was a significant increase in annual stillbirth rate at our institution; the rate exceeded both Australian national and state singleton stillbirth rates. After pregnancy terminations over 20 weeks were excluded from the data, there was no statistical change in the stillbirth rate over time. Congenital anomalies (27%) and unexplained antepartum death (15%) remained as major causes; fetal growth restriction (17%) was also identified as an increasingly important cause, particularly in preterm gestations. Termination of pregnancy after 20 weeks was found to be the cause of rising stillbirth rate at our institution. Local and national data collection on stillbirth should be standardised and should include differentiation of termination of pregnancy as a separate entity so as to accurately assess stillbirth to target appropriate research and resource allocation.

Rethinking placental pathology in the PSANZ classification of unexplained stillbirth at term.

Approximately 30 per cent of stillbirths are currently classified 'unexplained' using the Perinatal Society of Australia and New Zealand (PSANZ) classification system in New Zealand. This unexplained category includes deaths with placental pathology even though the importance of placental pathology and its causal relationship to stillbirth is well described. To determine whether unexplained stillbirths in New Zealand classified using PSANZ criteria can be more usefully classified based on placental pathology. Audit of the classification of cause of death among 'unexplained antepartum death' at term by perinatal pathologist review of postmortem and/or placental pathology reports using the current PSANZ Perinatal Death Classification (PDC)10 classification and a proposed 'significant placental pathology' subclassification. The main outcome measure was a change in cause of death from unexplained term stillbirth to an alternative PSANZ classification or to significant placental pathology subcategory. In total, 177 unexplained stillbirths with a postmortem and/or placental pathology report in New Zealand between 2007 and 2013 inclusive were reviewed. Twenty-three cases (13%) had significant placental pathology that could have been a direct cause of the stillbirth. A further seven cases (4%) were misclassified and could be better classified within another PDC category. A classification system incorporating placental pathologies which are recognised by the current literature to be causative of stillbirth would better describe stillbirths at term in New Zealand. This would benefit parental counselling and follow-up in subsequent pregnancies. A standard approach to reporting placental pathology would benefit clinicians. Education on placental pathology for clinicians working with parents experiencing stillbirth and multidisciplinary approach to classification is also recommended.

Pregnancy outcome in severe OHSS patients following ascitic/plerural fluid drainage.

BackgroundVarious inflammatory cytokines have been implicated in the pathophysiology of severe ovarian hyperstimulation syndrome, as well as, various pregnancy complications, including preterm labor, pregnancy induced hypertension/preeclampsia and intra-uterine growth restriction. We aim to determine whether severe OHSS, complicated by third space fluid accumulation necessitating drainage, is associated with increased risk of late obstetrics complications.MethodsWe assessed the obstetrics and neonatal outcome measures of 16 patients admitted to our gynecology ward during a 6-year period, with severe OHSS complicated by third space fluid accumulation necessitating drainage.ResultsPatients delivered at 37.3 ± 5.9weeks, with a mean birth weight of 3062 ± 757 gr. There was no single case of gestational diabetes, hypertensive diseases of pregnancy, nor placental abruption. Two (12.5%) patients had preterm delivery: one at 23 weeks’ gestation and one at 28 weeks’ gestation following preterm premature rupture of membrane. Another patient experienced an unexplained antepartum fetal death at 27 weeks’ gestation.ConclusionsSevere OHSS, complicated by third space fluid sequestration necessitating drainage, is not associated with adverse late pregnancy outcome, except probably for preterm labor. Following resolution of the OHSS, pregnancies should be regarded as any pregnancy resulting from IVF treatment, with special attention to prevent preterm labor.

The continuing dilemma of stillbirth

The continuing dilemma of stillbirth

The Auckland Stillbirth study, a case-control study exploring modifiable risk factors for third trimester stillbirth: methods and rationale

In high-income countries, stillbirth rates have been static in recent decades. Unexplained stillbirths account for up to 50% of these deaths. A case-control study was conducted in Auckland, New Zealand, from July 2006 to June 2009 to explore modifiable risk factors for late stillbirth (≥28 weeks of gestation). Eligible participants were women who had a singleton late stillbirth without a congenital abnormality. Two controls with ongoing pregnancies were randomly selected at the same gestation as each case. Data were collected through face-to-face interviews and from clinical records. A total of 155/215 (72%) cases and 310/429 (72%) controls consented to take part in the study. Women who had a late stillbirth were more likely to be of Pacific ethnicity and of parity ≥4 (OR = 1.7, 95% CI: 1.1-2.6 and 2.7, 95% CI: 1.4-5.3, respectively). The median gestational age at diagnosis of fetal death was 261 days (IQR 239-279), and the median gestation at which the controls were interviewed was 264.5 days (IQR 240-274) P = 0.48. 'Unexplained antepartum death' (n = 61, 39.4%) and 'fetal growth restriction' (n = 29, 18.7%) accounted for almost 60% of stillbirths. The post-mortem rate for all cases was 47% (73/155) and 43% (26/61) for those classified as 'unexplained antepartum death'. This study of risk factors for stillbirth is novel in that it used gestation-matched controls with ongoing pregnancies. Its detailed investigation into maternal health and behaviour during pregnancy has the potential to lead to a better understanding of modifiable risk factors for late stillbirth.

Systematic multidisciplinary approach to reporting perinatal mortality: Lessons from a five‐year regional review

Because of differences in reporting criteria throughout the world, comparing perinatal mortality rates and identifying areas of concern can be complicated and imprecise. To detail the systematic approach to reporting perinatal deaths and to identify any significant differences in outcomes in the Australian Capital Territory (ACT). Review of perinatal deaths from 2001 to 2005 in the ACT using the Australian and New Zealand Antecedent Classification of Perinatal Mortality (ANZACPM) and the Australian and New Zealand Neonatal Death Classification (ANZNDC) systems. ACT residents' perinatal mortality rate was 10.6 per 1000 total births, fetal death rate 7.5 per 1000 total births and neonatal death rate 3.2 per 1000 live births. The three leading antecedent causes of perinatal death were congenital anomalies, spontaneous preterm birth and unexplained antepartum death. The three leading causes of neonatal death were extreme prematurity, cardiorespiratory disorders and congenital anomalies. Multiple births attributed to 20% (65 of 321) of perinatal deaths. Perinatal autopsy was performed in 50% of cases, but in only 64% of unexplained antepartum deaths. Causes of perinatal death for the ACT and surrounding New South Wales region are similar to other states using this classification system. The following are considered important lessons to promote accurate perinatal mortality reporting: (i) a universal reporting system for Australia utilising a multidisciplinary team; (ii) a high perinatal autopsy rate, especially in the critical area of antepartum death with no identifiable cause; and (iii) standardised definitions for avoidability. Attention to these areas may prompt further research and changes in practice to further reduce perinatal mortality.

Classification and description of stillbirths in New South Wales, 2002–2004

To describe the pattern of stillbirths by cause and gestation period in New South Wales since the introduction of the Perinatal Society of Australia and New Zealand perinatal death classification (PSANZ-PDC); and to assess the agreement between classifications on cause of death between local hospital committees and the Perinatal Outcomes Working Party (POWP - a subgroup of the NSW Department of Health Ministerial Maternal and Perinatal Committee). Population-based retrospective cohort study of all 258 045 births in NSW and all 1264 stillbirths classified by the POWP in 2002-2004, based on linked data on perinatal deaths from the NSW Midwives Data Collection and the NSW Ministerial Maternal and Perinatal Committee. Pattern of stillbirths by cause and gestation period; and interobserver agreement on classification of cause of death (according to the PSANZ-PDC) between local hospital review committees and the POWP. The most common classification was unexplained antepartum death, comprising 41.5% of the cohort and 60% of stillbirths of > or = 37 weeks' gestation. These unexplained stillbirths were more likely to have had an autopsy performed than the explained stillbirths (45% v 36%; x2 = 10.1; df = 1; P = 0.001). Agreement on cause of death differed by cause of death classification, with an overall kappa statistic of 0.638. Unexplained antepartum death is the most common classification of stillbirths near term, and these stillbirths are more likely to have had an autopsy. Although reported interobserver agreement is high for PSANZ-PDC, in practice it is relatively low between hospital mortality review committees and the POWP.

Chorioamnionitis and fetal response in stillbirth

The purpose of this study was to determine the incidence of chorioamnionitis and fetal inflammatory response in a stillborn cohort and the relationship of fetal response to spontaneous labor, unexplained antepartum death, and spontaneous preterm death. In a 15-year hospital cohort study, placental histopathologic evidence, labor onset, gestation, and cause of death classification data were analyzed. Of 459 stillbirths, 428 stillbirths were included. The incidence of chorioamnionitis was 36.9%, with higher rates evident in early and late gestation. A fetal inflammatory response was present in 13.3% and correlated with spontaneous labor and very early spontaneous preterm death. The absence of a fetal response was associated with unexplained antepartum death. The increased incidence of chorioamnionitis at extremes of gestation in stillbirth is novel and has important implications. The impact of a fetal response is gestation dependent and its absence is associated with unexplained antepartum death.

Trends in the cause of late fetal death, 1982–2000

Progress in reducing late fetal deaths has slowed in recent years, despite changes in intrapartum and antepartum care. To describe recent trends in cause-specific fetal death rates. Retrospective cohort study. North of England. 3,386 late fetal deaths (> or = 28 weeks of gestation and at least 500 g), occuring between 1982 and 2000. Data on deaths were obtained from the Northern Perinatal Mortality Survey. Data on live births were obtained from national birth registration statistics. Rate ratios (RR) and 95% confidence intervals (CI) for fetal deaths in 1991-2000 compared with 1982-1990 were calculated. Cause-specific late fetal death rates per 10,000 total births. Mortality in singletons declined from 51.5 per 10,000 births in 1982-1990 to 42.0 in 1991-2000 (RR 0.82, 95% CI 0.76-0.87). There was a greater decline in multiples, from 197.9 to 128.0 per 10,000 (RR 0.65, 95% CI 0.51-0.83). In singletons, the largest reductions occurred in intrapartum-related deaths, and deaths due to congenital anomalies, antepartum haemorrhage and pre-eclampsia. There was little change in the rate of unexplained antepartum death occurring at term (RR 0.97, 95% CI 0.84-1.11) or preterm (RR 0.94, 95% CI 0.82-1.07), these accounting for about half of all late fetal deaths. Unexplained antepartum deaths declined in multiple births and in singletons of birthweight < 1500 g. While late fetal mortality due to many specific causes has declined, unexplained antepartum death rates have remained largely unchanged. Improved identification of deaths due to growth restriction and infection, which may otherwise be classified as unexplained, is important. Further investigation of the underlying aetiologies of genuinely unexplained deaths is needed.

Unexplained antepartum fetal deaths: what are the determinants?

The objective was to assess fetal, antenatal, and pregnancy determinants of unexplained antepartum fetal death. This is a hospital-based cohort study of 34,394 births weighing 500 g or more from January 1995 to December 2002. Unexplained fetal deaths were defined as fetal deaths occurring before labor, without evidence of significant fetal, maternal or placental pathology. Ninety-eight unexplained antepartum fetal deaths accounted for 27.2% of 360 total fetal deaths. Two-thirds of these deaths occurred after 36 weeks' gestation. The following factors are independently associated with unexplained fetal deaths: primiparity (OR 1.74; 95% CI 1.21, 2.86); parity of five or more (OR 1.19; 95% CI 1.26, 3.26); low socioeconomic status (OR 1.22; 95% CI 1.14, 2.86); maternal age 40 years or more (OR 3.62; 95% CI 1.22, 4.52); maternal age of 18 years or less (OR 1.79; 95% CI 0.82, 2.89); maternal prepregnancy weight greater than 70 kg (OR 2.20; 95% CI 1.85, 3.68); fewer than three antenatal visits in women whose fetuses died at 31 weeks or more (OR 1.11; 95% CI 1.08, 2.48); birth weight ratio (defined as ratio of birth weight to mean birth weight for gestational age) between 0.85 and 0.94 (OR 1.77; 95% CI 1.28, 4.18) or over 1.45 (OR 2.92; 95% CI 1.75, 3.21); trimester of first antenatal visit. Previous fetal death, previous abortion, cigarette smoking, fetal sex, low maternal weight, fetal-to-placenta weight, and post date pregnancy were not significantly associated with unexplained fetal deaths. Several factors were identified that are associated with an increased risk of unexplained fetal deaths.

Risk factors for unexplained antepartum fetal death in Norway 1967-1998.

To relate unexplained antepartum fetal death with maternal and fetal characteristics in order to identify risk factors. Population-based study based on records of 1,676,160 singleton births with gestational age > or =28 weeks. Unexplained antepartum fetal death was defined as fetal death before labour without known fetal, placental, or maternal pathology. Although unexplained fetal mortality in general declined from 2.4 per 1000 births in 1967-1976 to 1.6 in 1977-1998, the proportion among all fetal deaths increased from 30% to 43% during the same period of observation. Unexplained fetal death occurred later in gestation than explained. From 39 weeks of gestation, the risk increased progressively to 50/10,000 in women aged > or =35 years and <10/10,000 in women <25 years. In birth order > or =5, the risk was particularly high after 39 weeks of gestation. For birth weight percentile 2.5-9.9 and > or =97.5, unexplained fetal death was four and three times more likely to occur, respectively. We found an additive effect of maternal age and birth weight percentile 2.5-9.9. Women with less than 10 years education had higher risk than women with 13 years or more (OR=1.6). Weaker associations were observed with female gender, unmarried mothers, and winter season. Unexplained antepartum fetal death occurred later in gestation than explained and was associated with high maternal age, multiparity, low education, and moderately low and high birth weight percentile. The increased risk in post-term pregnancies and the additive effect of maternal age and birth weight percentile 2.5-9.9 suggests that older women would benefit from monitoring of fetal growth.

Determinants of unexplained antepartum fetal deaths

Objective: To assess fetal, maternal, and pregnancy-related determinants of unexplained antepartum fetal death. Methods: We conducted a hospital-based cohort study of 84,294 births weighing 500 g or more from 1961–1974 and 1978–1996. Unexplained fetal deaths were defined as fetal deaths occurring before labor without evidence of significant fetal, maternal, or placental pathology. Results: One hundred ninety-six unexplained antepartum fetal deaths accounted for 27.2% of 721 total fetal deaths. Two thirds of the unexplained fetal deaths occurred after 35 weeks’ gestation. The following factors were independently associated with unexplained fetal death: maternal prepregnancy weight greater than 68 kg (adjusted odds ratio [OR] 2.9; 95% confidence interval [CI] 1.85, 4.68), birth weight ratio (defined as ratio of birth weight to mean weight for gestational age) between 0.75 and 0.85 (OR 2.77; 95% CI 1.48, 5.18) or over 1.15 (OR 2.36; 95% CI 1.26, 4.44), fewer than four antenatal visits in women whose fetuses died at 37 weeks or later (OR 2.21; 95% CI 1.08, 4.52), primiparity (OR 1.74; 95% CI 1.26, 2.40), parity of three or more (OR 2.01; 95% CI 1.26, 3.20), low socioeconomic status (OR 1.59; 95% CI 1.14, 2.22), cord loops (OR 1.75; 95% CI 1.04, 2.97) and, for the 1978–1996 period only, maternal age 40 years or more (OR 3.69; 95% CI 1.28, 10.58). Trimester of first antenatal visit, low maternal weight, postdate pregnancy, fetal-to-placental weight ratio, fetal sex, previous fetal death, previous abortion, cigarette smoking, and alcohol use were not significantly associated with unexplained fetal death. Conclusion: In this study, we identified several factors associated with an increased risk of unexplained fetal death.

Uterine leiomyoma in pregnancy: its influence on obstetric performance.

To assess the effects of uterine leiomyoma on obstetrical performance. We reviewed the medical records of 102 women with singleton pregnancies who were found ultrasonographically to have uterine leiomyomas during the first half of their pregnancy and who gave birth at our hospital at > or = 22 weeks of gestation between January 1990 and December 1997. The 102 women gave birth to 101 healthy infants, weighing 2,974 +/- 579 g at 38.8 +/- 2.6 weeks of pregnancy. One woman experienced an unexplained antepartum fetal death at 24 weeks of gestation. Bleeding at the first trimester occurred in 16% of the women. Pain localized in the lower abdomen and requiring relief occurred in 28% of the women during the first or second trimester. Tocolytic treatment was required in 25% of the pregnancies, and preterm delivery occurred in 12% thereof. A cesarean section was performed in 39% of the pregnancies. Bleeding > or = 500 ml occurred at delivery in 48% of the cases. The largest fibroid, > 6 cm in diameter, which was seen in 51 women, was associated with higher frequencies of tocolytic treatment (41%), preterm delivery (24%), bleeding > or = 500 ml at delivery (59%), and cesarean delivery (51%). In 76 women (75%) who attempted vaginal delivery, the obstetrical outcome was comparable to that of 115 control women who were matched regarding age, parity, and gestational week. Although pain in the lower abdomen, the requirement of tocolytic treatment, preterm delivery, and cesarean delivery were common, the neonatal outcome was fairly good in women with uterine leiomyomas. The present data might be encouraging to pregnant women with uterine leiomyomas.