Rates of stillbirth by maternal region of birth and gestational age in New South Wales, Australia 2004–2015

Lifestyle and sociodemographic risk factors for stillbirth by region of residence in South Australia: a retrospective cohort study

BACKGROUND

Stillbirth rates remain a global priority and in Australia, progress has been slow. Risk factors of stillbirth are unique in Australia due to large areas of remoteness, and limited resource availability affecting the ability to identify areas of need and prevalence of factors associated with stillbirth. This retrospective cohort study describes lifestyle and sociodemographic factors associated with stillbirth in South Australia (SA), between 1998 and 2016.

METHODS

All restigered births in SA between 1998 ad 2016 are included. The primary outcome was stillbirth (birth with no signs of life ≥ 20 weeks gestation or ≥ 400 g if gestational age was not reported). Associations between stillbirth and lifestyle and sociodemographic factors were evaluated using multivariable logistic regression and described using adjusted odds ratios (aORs).

RESULTS

A total of 363,959 births (including 1767 stillbirths) were included. Inadequate antenatal care access (assessed against the Australian Pregnancy Care Guidelines) was associated with the highest odds of stillbirth (aOR 3.93, 95% confidence interval (CI) 3.41-4.52). Other factors with important associations with stillbirth were plant/machine operation (aOR, 1.99; 95% CI, 1.16-2.45), birthing person age ≥ 40 years (aOR, 1.92; 95% CI, 1.50-2.45), partner reported as a pensioner (aOR, 1.83; 95% CI, 1.12-2.99), Asian country of birth (aOR, 1.58; 95% CI, 1.19-2.10) and Aboriginal/Torres Strait Islander status (aOR, 1.50; 95% CI, 1.20-1.88). The odds of stillbirth were increased in regional/remote areas in association with inadequate antenatal care (aOR, 4.64; 95% CI, 2.98-7.23), birthing age 35-40 years (aOR, 1.92; 95% CI, 1.02-3.64), Aboriginal and/or Torres Strait Islander status (aOR, 1.90; 95% CI, 1.12-3.21), paternal occupations: tradesperson (aOR, 1.69; 95% CI, 1.17-6.16) and unemployment (aOR, 4.06; 95% CI, 1.41-11.73).

CONCLUSION

Factors identified as independently associated with stillbirth odds include factors that could be addressed through timely access to adequate antenatal care and are likely relevant throughout Australia. The identified factors should be the target of stillbirth prevention strategies/efforts. SThe stillbirth rate in Australia is a national concern. Reducing preventable stillbirths remains a global priority.

Causes of stillbirth in ethnically diverse women in a Perth metropolitan hospital: A retrospective study

BACKGROUND

Most published reports analysing the differences in causation of stillbirth between different ethnic groups focus on stillbirth risk factors, with a paucity of data comparing actual causes of stillbirth.

AIMS

To determine whether causes of stillbirth differ between Caucasian and non-Caucasian ethnic groups in an Australian context.

MATERIALS AND METHODS

Data from all stillbirths occurring at 20 or more completed weeks of gestation between 1 January 2010 and 31 December 2020 at a secondary level, outer metropolitan hospital, were analysed in this retrospective case series. Causes of stillbirth as determined by perinatal autopsy and placental histopathology were categorised using the Perinatal Society of Australia and New Zealand Perinatal Death Classification and compared between Caucasian and non-Caucasian groups.

RESULTS

Ninety-two stillbirths (0.7% of all births) were identified during the study period. A greater proportion of non-Caucasian women had small for gestation age placentas compared to Caucasian women (n = 22/43 (51%) vs n = 12/49 (24%); P = 0.025). A greater proportion of stillbirths were caused by hypoxic peripartum death in non-Caucasian than in Caucasian women (n = 4/43 (9%) vs n = 0/49 (0%); P = 0.044), and a greater prevalence of placental dysfunction was seen in the non-Caucasian cohort compared to Caucasian women (n = 14/43 (33%) vs n = 8/49 (16%); P = 0.057).

CONCLUSIONS

The differences observed in causes of stillbirth between Caucasian and non-Caucasian women are hypothesis generating and warrant further larger-scale, multi-centred studies using standardised definitions and classification systems to determine whether these differences persist in a more representative sample.

Association of Maternal Risk Factors with the Prevalence of Caesarean Section Deliveries: A Cross-Sectional Study

In the last few years, there has been a gradually increasing rate of caesarean section deliveries worldwide that negatively affects both mothers' and children's health. The present survey intended to explore the relations of common maternal risk factors with the prevalence of caesarean sections. This is a cross-sectional study including 5182 healthy mothers from geographically diverse regions of Greece, which has applied relevant inclusion and exclusion criteria. An elevated 56.4% incidence of caesarean sections was noted. The prevalence of caesarean section deliveries was estimated to be 51.5% in private hospitals and 48.5% in public hospitals. Maternal age, pre-pregnancy overweight/obesity, excess gestational weight gain, preterm birth, financial status, smoking habits, and private type of birth hospital were considerably associated with a high probability of caesarean section, regardless of several confounders. In conclusion, caesarean section rates are constantly increasing, and various maternal risk factors additively elevate its incidence, which additionally enhances the likelihood of postpartum complications for both the mothers and their infants. Public health procedures and approaches are strongly recommended to notify future mothers of the potential risk factors that may result in adverse pregnancy outcomes of caesarean section delivery, highlighting its use only for emergency medical reasons and also promoting healthier nutritional and lifestyle habits that may reduce the increasing prevalence of caesarean section deliveries.

Fetal surveillance from 39 weeks' gestation to reduce stillbirth in South Asian-born women

BACKGROUND

In July 2017, the State of Victoria's largest maternity service implemented a new clinical guideline to reduce the rates of stillbirth at term for South Asian women.

OBJECTIVE

This study aimed to evaluate the impact of offering fetal surveillance from 39 weeks to South Asian-born women on rates of stillbirth and neonatal and obstetrical interventions.

STUDY DESIGN

This was a cohort study of all women receiving antenatal care at 3 large metropolitan university-affiliated teaching hospitals in Victoria, who gave birth in the term period between January 2016 and December 2020. Differences in rates of stillbirth, neonatal deaths, perinatal morbidities, and interventions after July 2017 were determined. Multigroup interrupted time-series analysis was used to assess changes in rates of stillbirth and induction of labor.

RESULTS

A total of 3506 South Asian-born women gave birth before, and 8532 after the change in practice. There was a 64% reduction in term stillbirth (95% confidence interval, 87% to 2%; P=.047) after the change in practice from 2.3 per 1000 births to 0.8 per 1000 births. The rates of early neonatal death (3.1/1000 vs 1.3/1000; P=.03) and special care nursery admission (16.5% vs 11.1%; P<.001) also decreased. There were no significant differences in admission to the neonatal intensive care unit, 5-minute Apgar score <7, or birthweight, or differences in the trends of induction of labor per month.

CONCLUSION

Fetal monitoring from 39 weeks may offer an alternative to routine earlier induction of labor to reduce the rates of stillbirth without causing an increase in neonatal morbidity and attenuating trends in obstetrical interventions.

Grouping women of South Asian ethnicity for pregnancy research in New Zealand

BACKGROUND

The New Zealand (NZ) Ministry of Health ethnicity data protocols recommend that people of South Asian (SAsian) ethnicity, other than Indian, are combined with people of Japanese and Korean ethnicity at the most commonly used level of aggregation in health research (level two). This may not work well for perinatal studies, as it has long been observed that women of Indian ethnicity have higher rates of adverse pregnancy outcomes, such as perinatal death. It is possible that women of other SAsian ethnicities share this risk.

AIMS

This study was performed to identify appropriate groupings of women of SAsian ethnicity for perinatal research.

MATERIALS AND METHODS

National maternity and neonatal data, and singleton birth records between 2008 and 2017 were linked using the Statistics NZ Integrated Data Infrastructure. Socio-demographic risk profiles and pregnancy outcomes were compared between 15 ethnic groups. Recommendations were made based on statistical analyses and cultural evaluation with members of the SAsian research community.

RESULTS

Similarities were observed between women of Indian, Fijian Indian, South African Indian, Sri Lankan, Bangladeshi and Pakistani ethnicities. A lower-risk profile was seen among Japanese and Korean mothers. Risk profiles of women of combined Indian-Māori, Indian-Pacific and Indian-New Zealand European ethnicity more closely represented their corresponding non-Indian ethnicities.

CONCLUSIONS

Based on these findings, we suggest a review of current NZ Ministry of Health ethnicity data protocols. We recommend that researchers understand the risk profiles of participants prior to aggregation of groups in research, to mitigate risks associated with masking differences.

An in-depth analysis of perinatal related mortality among women of South Asian ethnicity in Aotearoa New Zealand

BACKGROUND

International and national New Zealand (NZ) research has identified women of South Asian ethnicity at increased risk of perinatal mortality, in particular stillbirth, with calls for increased perinatal research among this ethnic group. We aimed to analyse differences in pregnancy outcomes and associated risk factors between South Asian, Māori, Pacific and NZ European women in Aotearoa NZ, with a focus on women of South Asian ethnicity, to ultimately understand the distinctive pathways leading to adverse events.

METHODS

Clinical data from perinatal deaths between 2008 and 2017 were provided by the NZ Perinatal and Maternal Mortality Review Committee, while national maternity and neonatal data, and singleton birth records from the same decade, were linked using the Statistics NZ Integrated Data Infrastructure for all births. Pregnancy outcomes and risk factors for stillbirth and neonatal death were compared between ethnicities with adjustment for pre-specified risk factors.

RESULTS

Women of South Asian ethnicity were at increased risk of stillbirth (aOR 1.51, 95%CI 1.29-1.77), and neonatal death (aOR 1.51, 95%CI 1.17-1.92), compared with NZ European. The highest perinatal related mortality rates among South Asian women were between 20-23 weeks gestation (between 0.8 and 1.3/1,000 ongoing pregnancies; p < 0.01 compared with NZ European) and at term, although differences by ethnicity at term were not apparent until ≥ 41 weeks (p < 0.01). No major differences in commonly described risk factors for stillbirth and neonatal death were observed between ethnicities. Among perinatal deaths, South Asian women were overrepresented in a range of metabolic-related disorders, such as gestational diabetes, pre-existing thyroid disease, or maternal red blood cell disorders (all p < 0.05 compared with NZ European).

CONCLUSIONS

Consistent with previous reports, women of South Asian ethnicity in Aotearoa NZ were at increased risk of stillbirth and neonatal death compared with NZ European women, although only at extremely preterm (< 24 weeks) and post-term (≥ 41 weeks) gestations. While there were no major differences in established risk factors for stillbirth and neonatal death by ethnicity, metabolic-related factors were more common among South Asian women, which may contribute to adverse pregnancy outcomes in this ethnic group.

Placental pathology findings in perinatal deaths from 28 weeks gestation in Aotearoa New Zealand

INTRODUCTION

Women of South Asian ethnicity are overrepresented in adverse pregnancy outcome across high-income countries, including those related to placental dysfunction. It has been hypothesised that placental aging occurs at earlier gestation in South Asian pregnancies. We aimed to identify differences in placental pathology among perinatal deaths ≥28 weeks gestation, between South Asian, Māori and New Zealand (NZ) European women in Aotearoa NZ, with a focus on women of South Asian ethnicity.

METHODS

Placental pathology reports and clinical data from perinatal deaths between 2008 and 2017 were provided by the NZ Perinatal and Maternal Mortality Review Committee, blinded, and analysed by an experienced perinatal pathologist using the Amsterdam Placental Workshop Group Consensus Statement criteria.

RESULTS

790 of 1161 placental pathology reports, 346 preterm (28⁺⁰ to 36⁺⁶ weeks) and 444 term (≥37⁺⁰ weeks) deaths, met the inclusion criteria. Among preterm deaths, South Asian women had higher rates of maternal vascular malperfusion compared with Māori (aOR 4.16, 95%CI 1.55-11.15) and NZ European (aOR 2.60, 95%CI 1.10-6.16). Among term deaths, South Asian women had higher rates of abnormal villous morphology compared with Māori (aOR 2.19, 95%CI 1.04-4.62) and NZ European (aOR 2.12, 95%CI 1.14-3.94), mostly due to increased rates of chorangiosis (36.7%, compared to 23.3% and 21.7%, respectively).

DISCUSSION

Differences in placental pathology by ethnicity were observed among preterm and term perinatal deaths. While we suspect differing underlying causal pathways, these deaths may be associated with maternal diabetic and red blood cell disorders among South Asian women, leading to a hypoxic state in-utero.

Placental pathology findings amongst extremely preterm perinatal deaths in Aotearoa New Zealand

INTRODUCTION

Women of South Asian ethnicity are overrepresented in adverse pregnancy outcomes across high-income countries, including placental dysfunction and antepartum haemorrhage. As the burden of mortality is highest for extremely preterm infants, we aimed to identify any differences in placental pathology among perinatal deaths from 20⁺⁰ to 27⁺⁶ weeks gestation between South Asian, Māori and New Zealand (NZ) European women in Aotearoa NZ, with a focus on women of South Asian ethnicity.

METHODS

Placental pathology reports and clinical data from perinatal deaths between 2008 and 2017 were provided by the NZ Perinatal and Maternal Mortality Review Committee, blinded and analysed by an experienced perinatal pathologist using the Amsterdam Placental Workshop Group Consensus Statement criteria. South Asian ethnicity was classified as Indian, Fijian Indian, South African Indian, Sri Lankan, Pakistani and Bangladeshi.

RESULTS

886 of 1571 placental pathology reports met the inclusion criteria. Women of South Asian ethnicity were significantly more likely to show features of histologic chorioamnionitis (aOR 1.87, 95%CI 1.19-2.94) and chorionic vasculitis (aOR 1.92, 95%CI 1.13-3.29), than NZ European and Māori women respectively. 13 of 15 (87%) of South Asian mothers with a diabetic disorder were identified with chorioamnionitis, compared to 1 in 5 (20%) of Māori and 5 in 12 (41%) of NZ European women. Cord hyper-coiling was also more common among South Asian pregnancies, compared to NZ European (aOR 1.98, 95%CI 1.10-3.56).

DISCUSSION

Differences in placental pathology by ethnicity were observed among extremely preterm perinatal deaths. Underlying metabolic disorders and an associated pro-inflammatory environment may play an important role in the causal pathway leading to these deaths in women of South Asian ethnicity.

Maternal Race and Stillbirth: Cohort Study and Systematic Review with Meta-Analysis

Accurate identification of independent predictors of stillbirth is needed to define preventive strategies. We aim to examine the independent contribution of maternal race in the risk of stillbirth after adjusting for maternal characteristics and medical history. There are two components to the study: first, prospective screening in 168,966 women with singleton pregnancies coordinated by the Fetal Medicine Foundation (FMF) and second, a systematic review and meta-analysis of studies reporting on race and stillbirth. In the FMF study, logistic regression analysis found that in black women, the risk of stillbirth, after adjustment for confounders, was higher than in white women (odds ratio 1.78, 95% confidence interval 1.50 to 2.11). The risk for other racial groups was not significantly different. The literature search identified 20 studies that provided data on over 6,500,000 pregnancies, but only 10 studies provided risks adjusted for some maternal characteristics; consequently, the majority of these studies did not provide accurate contribution of different racial groups to the prediction of stillbirth. It is concluded that in women of black origin, the risk of stillbirth, after adjustment for confounders, is about twofold higher than in white women. Consequently, closer surveillance should be granted for these women.

Fetal monitoring from 39 weeks' gestation to identify South Asian-born women at risk of perinatal compromise: a retrospective cohort study

To investigate whether earlier “post-term” monitoring of South Asian (SA) pregnancies from 39 weeks’ gestation with amniotic fluid index (AFI) and cardiotocography (CTG) detected suspected fetal compromise. Retrospective cohort study of all SA-born women at an Australian health service with uncomplicated, singleton pregnancies following the introduction of twice-weekly AFI and CTG monitoring from 39 weeks. Monitoring results, and their association with a perinatal compromise composite (including assisted delivery for fetal compromise, stillbirth, and NICU admission) were determined. 771 SA-born women had earlier monitoring, triggering delivery in 82 (10.6%). 31 (4%) had a non-reassuring antepartum CTG (abnormal fetal heart rate or variability, or decelerations) and 21 (2.7%) had an abnormal AFI (≤ 5 cm). Women with abnormal monitoring were 53% (95% CI 1.2–1.9) more likely to experience perinatal compromise and 83% (95% CI 1.2–2.9) more likely to experience intrapartum compromise than women with normal monitoring. Monitoring from 39 weeks identified possible fetal compromise earlier than it otherwise would have been, and triggered intervention in 10% of women. Without robust evidence to guide timing of birth in SA-born women to reduce rates of stillbirth, earlier monitoring provides an alternative to routine induction of labour.

Rates of neonatal morbidity by maternal region of birth and gestational age in New South Wales, Australia 2003-2016

INTRODUCTION

Research suggests that neonatal morbidity differs by maternal region of birth at different gestational ages. This study aimed to determine the overall and gestation-specific risk of neonatal morbidity by maternal region of birth, after adjustment for maternal, infant and birth characteristics, for women giving birth in New South Wales, Australia, from 2003 to 2016.

MATERIAL AND METHODS

The study utilized a retrospective cohort study design using linked births, hospital and deaths data. Modified Poisson regression was used to determine risk with 95% confidence intervals (95% CI) of neonatal morbidity by maternal region of birth, overall and at each gestational age, compared with Australian or New Zealand-born women giving birth at 39 weeks.

RESULTS

There were 1 074 930 live singleton births ≥32 weeks' gestation that met the study inclusion criteria, and 44 394 of these were classified as morbid, giving a neonatal morbidity rate of 4.13 per 100 live births. The gestational age-specific neonatal morbidity rate declined from 32 weeks' gestation, reaching a minimum at 39 weeks in all maternal regions of birth. The unadjusted neonatal morbidity rate was highest in South Asian-born women at most gestations. Adjusted rates of neonatal morbidity between 32 and 44 weeks were significantly lower for babies born to East (adjusted relative risk [aRR] 0.65, 95% CI 0.62-0.68), South-east (aRR 0.76, 95% CI 0.73-0.79) and West Asian-born (aRR 0.93, 95% CI 0.88-0.98) mothers, and higher for babies of Oceanian-born (aRR 1.11, 95% CI 1.04-1.18) mothers, compared with Australian or New Zealand-born mothers. Babies of African, Oceanian, South Asian and West Asian-born women had a lower adjusted risk of neonatal morbidity than Australian or New Zealand-born women until 37 or 38 weeks' gestation, and thereafter an equal or higher risk in the term and post-term periods.

CONCLUSIONS

Maternal region of birth is an independent risk factor for neonatal morbidity in New South Wales.