Determinants of increases in stillbirth rates from 2000 to 2010

Effect of the COVID-19 Pandemic on Stillbirths in Canada and the United States

OBJECTIVE

There is uncertainty regarding the effect of the COVID-19 pandemic on population rates of stillbirth. We quantified pandemic-associated changes in stillbirth rates in Canada and the United States.

METHODS

We carried out a retrospective study that included all live births and stillbirths in Canada and the United States from 2015 to 2020. The primary analysis was based on all stillbirths and live births at ≥20 weeks gestation. Stillbirth rates were analyzed by month, with March 2020 considered to be the month of pandemic onset. Interrupted time series analyses were used to determine pandemic effects.

RESULTS

The study population included 18 475 stillbirths and 2 244 240 live births in Canada and 134 883 stillbirths and 22 963 356 live births in the United States (8.2 and 5.8 stillbirths per 1000 total births, respectively). In Canada, pandemic onset was associated with an increase in stillbirths at ≥20 weeks gestation of 1.01 (95% confidence interval [CI] 0.56-1.46) per 1000 total births and an increase in stillbirths at ≥28 weeks gestation of 0.35 (95% CI 0.16-0.54) per 1000 total births. In the United States, pandemic onset was associated with an increase in stillbirths at ≥20 weeks gestation of 0.48 (95% CI 0.22-0.75) per 1000 total births and an increase in stillbirths at ≥28 weeks gestation of 0.22 (95% CI 0.12-0.32) per 1000 total births. The increase in stillbirths at pandemic onset returned to pre-pandemic levels in subsequent months.

CONCLUSION

The COVID-19 pandemic's onset was associated with a transitory increase in stillbirth rates in Canada and the United States.

Temporal trends in stillbirth over eight decades in England and Wales: A longitudinal analysis of over 56 million births and lives saved by improvements in maternity care

Background

Considering the public health importance of stillbirth, this study quantified the trends in stillbirths over eight decades in England and Wales.

Methods

This longitudinal study utilized the publicly available aggregated data from the Office for National Statistics that captured maternity information for babies delivered in England and Wales from 1940 to 2019. We computed the trends in stillbirth with the associated incidence risk difference, incidence risk ratio, and extra lives saved per decade.

Results

From 1940-2019, 56 906 273 births were reported. The stillbirth rate declined (85%) drastically up to the early 1980s. In the initial five decades, the estimated number of deaths per decade further decreased by 67 765 (9.49/1000 births) in 1940-1949, 2569 (0.08/1000 births) in 1950-1959, 9121 (3.50/1000 births) in 1960-1969, 15 262 (2.31/1000 births) in 1970-1979, and 10 284 (1.57/1000 births) in 1980-1989. However, the stillbirth rate increased by an additional 3850 (0.58/1000 births) stillbirths in 1990-1999 and 693 (0.11/1000 births) stillbirths in 2000-2009. The stillbirth rate declined again during 2010-2019, with 3714 fewer stillbirths (0.54/1000 births). The incidence of maternal age <20 years reduced over time, but pregnancy among older women (>35 years) increased.

Conclusions

The stillbirth rate declined drastically, but the rate of decline slowed in the last three decades. Though teenage pregnancy (<20 years) had reduced, the prevalence of women with a higher risk of stillbirth may have risen due to an increase in advanced maternal age. Improved, more personalised care is required to reduce the stillbirth rate further.

Clarity and consistency in stillbirth reporting in Europe: why is it so hard to get this right?

Background

Stillbirth is a major public health problem, but measurement remains a challenge even in high-income countries. We compared routine stillbirth statistics in Europe reported by Eurostat with data from the Euro-Peristat research network.

Methods

We used data on stillbirths in 2015 from both sources for 31 European countries. Stillbirth rates per 1000 total births were analyzed by gestational age (GA) and birthweight groups. Information on termination of pregnancy at ≥22 weeks’ GA was analyzed separately.

Results

Routinely collected stillbirth rates were higher than those reported by the research network. For stillbirths with a birthweight ≥500 g, the difference between the mean rates of the countries for Eurostat and Euro-Peristat data was 22% [4.4/1000, versus 3.5/1000, mean difference 0.9 with 95% confidence interval (CI) 0.8–1.0]. When using a birthweight threshold of 1000 g, this difference was smaller, 12% (2.9/1000, versus 2.5/1000, mean difference 0.4 with 95% CI 0.3–0.5), but substantial differences remained for individual countries. In Euro-Peristat, missing data on birthweight ranged from 0% to 29% (average 5.0%) and were higher than missing data for GA (0–23%, average 1.8%).

Conclusions

Routine stillbirth data for European countries in international databases are not comparable and should not be used for benchmarking or surveillance without careful verification with other sources. Recommendations for improvement include using a cut-off based on GA, excluding late terminations of pregnancy and linking multiple sources to improve the quality of national databases.

Pregnancy outcomes during the COVID-19 pandemic in Canada, March to August 2020

OBJECTIVE

Several studies have documented changes in the rates preterm birth and stillbirth during the COVID-19 pandemic. We carried out a study to examine obstetric intervention, preterm birth, and stillbirth rates in Canada from March to August 2020.

METHODS

The study included all singleton hospital deliveries in Canada (excluding Québec) from March to August 2020 (and March to August for the years 2015-2019) with information obtained from the Canadian Institute for Health Information. Data for Ontario were examined separately because this province had the highest rates of COVID-19 in the study population. Rates and odds ratios with 95% confidence intervals (CIs) were used to quantify pregnancy-related outcomes.

RESULTS

There were 136,445 and 717,905 singleton hospital deliveries in Canada (excluding Quebéc) in from March to August 2020 and between March and August 2015-2019, respectively. Rates of obstetric intervention declined in early gestation in 2020. Odds ratios for labour induction and cesarean delivery at <32 weeks gestation for March-August 2020 versus March-August in 2015 to 2019 were 0.84 (95% CI 0.74-0.95) and 0.92 (95% CI 0.85-1.00), respectively. Preterm birth rates increased in Canada (excluding Québec) from 6.42% in March-August 2015 to 6.74% in March-August 2019 but were unchanged in March-August 2020 (6.74%). Stillbirth rates were stable between March-August 2015 and March-August 2020. However, stillbirth rates peaked in Ontario in April 2020 due to higher rates of stillbirths at 20-27 and 37-41 weeks gestation.

CONCLUSION

Changes in labour induction and cesarean delivery at early gestation and other perinatal outcomes during the period of March to August 2020 highlight the need to reconsider the use and impact of obstetric services in pandemics as well as the need for timely perinatal surveillance.

Converging or diverging trajectories of mortality under one year of age in the Baltic States: a comparison with the European Union

BACKGROUND

Information about trends in perinatal and child health inequalities is scarce, especially in the Eastern Europe. We analyzed how mortality under 1 year of age has been changing in the Baltic States and the European Union (EU) over 25 years, and what associations occurred between changes in macroeconomic factors and mortality.

METHODS

Data on fetal, neonatal, infant mortality, and macroeconomic factors were extracted from WHO database. Joinpoint regression analysis was performed to analyze time trajectories of mortality over 1990-2014. We also investigated how the changes in health expenditures and Gross Domestic Product (GDP) contributed to the changes in mortality.

RESULTS

The reduction of fetal, neonatal and infant mortality in the Baltic countries led to convergence with the EU. In Estonia this process was the fastest, and then the rates tended to diverge. The strongest effect in reduction of neonatal mortality was related to the annual increase in health expenditure and GDP which had occurred in the same year, and a decrease in fetal mortality associated with an increase in health expenditure and GDP in the 4th and 5th year, respectively, following the initial change.

CONCLUSIONS

These findings outlined convergences and divergences in mortality under 1 year of age in the Baltic States compared with the patterns of the EU. Our data highlighted a need to define health policy directions aimed at the implementation of effective intervention modalities addressing reduction of risks in prenatal and early life.

Stillbirth in Canada: anachronistic definition and registration processes impede public health surveillance and clinical care

The archaic definition and registration processes for stillbirth currently prevalent in Canada impede both clinical care and public health. The situation is fraught because of definitional problems related to the inclusion of induced abortions at ≥20 weeks’ gestation as stillbirths: widespread uptake of prenatal diagnosis and induced abortion for serious congenital anomalies has resulted in an artefactual temporal increase in stillbirth rates in Canada and placed the country in an unfavourable position in international (stillbirth) rankings. Other problems with the Canadian stillbirth definition and registration processes extend to the inclusion of fetal reductions (for multi-fetal pregnancy) as stillbirths, and the use of inconsistent viability criteria for reporting stillbirth. This paper reviews the history of stillbirth registration in Canada, provides a rationale for updating the definition of fetal death and recommends a new definition and improved processes for fetal death registration. The recommendations proposed are intended to serve as a starting point for reformulating issues related to stillbirth, with the hope that building a consensus regarding a definition and registration procedures will facilitate clinical care and public health.

Stillbirths in women with pre-gravid obesity

Objective To determine the association between pre-gravid obesity and stillbirth. Methods A retrospective study of a population-based dataset of births at ≥34 weeks' gestation. We excluded fetal deaths due to lethal anomalies and intrapartum fetal deaths. We calculated the incidence of stillbirths, neonatal respiratory distress syndrome (RDS) and neonatal intensive care unit (NICU) admissions per ongoing pregnancies for each gestational week in the two body mass index (BMI) categories (≥30 vs.<30). Results Pre-pregnancy obesity (BMI≥30), pre-pregnancy diabetes, oligo- and polyhydramnios, being small for gestational age (SGA) and preeclampsia were significantly associated with stillbirth. However, the only pre-gravid factor that is amenable to intervention was obesity [adjusted odds ratio (OR) 2.0; 95% confidence interval (CI) 1.20, 3.3]. The rates of stillbirth seem to increase with gestational age in both BMI categories. RDS and NICU admission would be presented. Conclusion Birth near term might reduce stillbirths and decrease NICU admissions occurring in term and in post-term obese women. This presumable advantage might be offset by the potential risk of labor induction and cesarean section among obese women. Women of childbearing age with a BMI≥30 should be counseled about these risks of obesity during pregnancy and childbirth.

Stillbirth: Perceptions among hospital staff in the Middle East and the UK

Objectives Stillbirth is an important and yet relatively unacknowledged public health concern in many parts of the world. Public awareness of stillbirth and its potentially modifiable risk factors is a prerequisite to planning prevention measures. Cultural and regional differences may play an important role in awareness and attitudes to stillbirth prevention. The objective of this study was to evaluate and compare the awareness of stillbirth among hospital staff in Qatar and the UK, representing two culturally different regions.

Study design An online population survey for anonymous completion was sent to the hospital email accounts of all grades of staff (clinical and non-clinical) at two hospitals in Qatar and one tertiary hospital Trust in the UK. The survey was used to gather information on the participants’ demographic background, the experience of stillbirth, knowledge of stillbirth, awareness of information and support sources, as well as attitude towards investigation and litigation. Data were analysed using descriptive and comparative statistics (Chi-Square test and Fisher’s exact test).

Results 1002 respondents completed the survey, including 349 in the Qatar group and 653 in the UK group. There were significant differences in group demographics in terms of language, religion, gender, nationality and experience of stillbirth. The groups also differed significantly in the knowledge of stillbirth, its incidence and risk factors. The two groups took different views on apportioning blame on healthcare services in cases of stillbirth. The Qatar group showed significantly less awareness of available support organisations and relied significantly more on online sources of information for stillbirths (p < 0.001).

Conclusions This comparative study demonstrated significant differences between the two culturally distinct regions in the awareness, knowledge and attitudes towards stillbirths. The complex cultural and other factors that may be contributory should be further studied. The results highlight the need for increasing public awareness around stillbirth as part of effective prevention strategies.

Indications leading to termination of pregnancy between 22+0 and 31+6 weeks of gestational age in France: A population-based cohort study

OBJECTIVE

To estimate the prevalence and indications of terminations of pregnancy (TOP) between 22⁺⁰ and 31⁺⁶ weeks of gestational age in France and to examine the characteristics of women by indication of TOP.

STUDY DESIGN

From the EPIPAGE 2 population-based cohort study of preterm births in France in 2011, we selected 5009 singleton live births, stillbirths and TOP that occurred between 22 and 31 weeks. We estimated the proportion of TOP by gestational age. We then classified terminations by indications into 4 categories: fetal anomalies (TOPFA), preterm premature rupture of the membranes (PPROM), maternal conditions and fetal growth restriction (FGR). We also classified TOPFA by type of anomaly. Maternal characteristics were compared between TOPFA and TOP for maternal or fetal conditions without congenital anomaly.

RESULTS

23.1% of all births and 54.3% of stillbirths were terminations. The proportion of terminations was 36.9% of all births at 22 weeks, 50.2% at 24 weeks and <10% at 30-31 weeks. 85.8% of terminations were for fetal anomaly, 4.4% for PPROM, 6.1% for maternal complications and 3.7% for severe FGR. Compared to women with a TOPFA, those with a termination for maternal or fetal conditions were more often nulliparous, single, African, obese, smokers and covered by non-standard insurance for women in socially deprived circumstances.

CONCLUSION

In France, there is a high proportion of TOP of which 14% are for indications other than congenital anomalies. Because rates of terminations have an impact on very preterm birth and perinatal mortality rates, studies on pregnancy outcome should report all terminations, not only those for congenital anomalies.

Quantifying the burden of stillbirths before 28 weeks of completed gestational age in high-income countries: a population-based study of 19 European countries

BACKGROUND

International comparisons of stillbirth allow assessment of variations in clinical practice to reduce mortality. Currently, such comparisons include only stillbirths from 28 or more completed weeks of gestational age, which underestimates the true burden of stillbirth. With increased registration of early stillbirths in high-income countries, we assessed the reliability of including stillbirths before 28 completed weeks in such comparisons.

METHODS

In this population-based study, we used national cohort data from 19 European countries participating in the Euro-Peristat project on livebirths and stillbirths from 22 completed weeks of gestation in 2004, 2010, and 2015. We excluded countries without national data for stillbirths by gestational age in these periods, or where data available were not comparable between 2004 and 2015. We also excluded those countries with fewer than 10 000 births per year because the proportion of stillbirths at 22 weeks to less than 28 weeks of gestation is small. We calculated pooled stillbirth rates using a random-effects model and changes in rates between 2004 and 2015 using risk ratios (RR) by gestational age and country.

FINDINGS

Stillbirths at 22 weeks to less than 28 weeks of gestation accounted for 32% of all stillbirths in 2015. The pooled stillbirth rate at 24 weeks to less than 28 weeks declined from 0·97 to 0·70 per 1000 births from 2004 to 2015, a reduction of 25% (RR 0·75, 95% CI 0·65-0·85). The pooled stillbirth rate at 22 weeks to less than 24 weeks of gestation in 2015 was 0·53 per 1000 births and did not significantly changed over time (RR 0·97, 95% CI 0·80-1·16) although changes varied widely between countries (RRs 0·62-2·09). Wide variation in the percentage of all births occurring at 22 weeks to less than 24 weeks of gestation suggest international differences in ascertainment.

INTERPRETATION

Present definitions used for international comparisons exclude a third of stillbirths. International consistency of reporting stillbirths at 24 weeks to less than 28 weeks suggests these deaths should be included in routinely reported comparisons. This addition would have a major impact, acknowledging the burden of perinatal death to families, and making international assessments more informative for clinical practice and policy. Ascertainment of fetal deaths at 22 weeks to less than 24 weeks should be stabilised so that all stillbirths from 22 completed weeks of gestation onwards can be reliably compared.

FUNDING

EU Union under the framework of the Health Programme and the Bridge Health Project.

Improving, but could do better: Trends in gestation-specific stillbirth in Australia, 1994-2015

BACKGROUND

Stillbirth remains a public health concern in high-income countries. Over the past 20 years, stillbirth rates globally have shown little improvement and large disparities. The overall stillbirth rate, which measures risk among births at all gestations, masks diverging trends at different gestations. This study investigates trends over time in gestation-specific risk of stillbirth in Australia.

METHODS

Analytical epidemiological study using nationally reported gestational age data for births in Australia, 1994-2015. Average annual change in gestation-specific prospective risk of stillbirth (per 1000 fetuses at risk [FAR]) was calculated among births in 1994-2009 and 2010-2015 at term (37-41 weeks) and for preterm gestational age subgroups: 28-36, 24-27, and 20-23 weeks.

RESULTS

The decline in risk of stillbirth at term from 2010 to 2015 from 1.43 to 1.16 per 1000 FAR was more rapid than from 1994 to 2009; for preterm gestations from 24 to 27 weeks, there were no discernible trends; from 28 to 36 weeks, the decline between 1994 and 2009 was not sustained; among births from 20 to 23 weeks, the risk of stillbirth plateaued in 2010-2015, fluctuating around 3.3 per 1000 FAR.

CONCLUSIONS

Improvement in the stillbirth rate from 28 weeks' gestation aligns with changes in other high-income countries, but more work is needed in Australia to achieve the levels of reduction seen elsewhere. Gestation-specific risk of stillbirth is more informative than the overall stillbirth rate. The message that the overall risk of stillbirth is not changing disregards gains at different stages of pregnancy.

Methodological Challenges in International Comparisons of Perinatal Mortality

PURPOSE OF REVIEW

Several prestigious agencies routinely rank countries based on crude perinatal and infant mortality rates, while more recently, international neonatal networks have begun comparing neonatal mortality and morbidity rates among very preterm and very low-birth-weight infants. We discuss the methodologic challenges that compromise such comparisons and potential remedies.

RECENT FINDINGS

Crude perinatal mortality rates are biased by international variations in birth registration, especially at the borderline of viability. Such bias is demonstrated by significant differences in crude versus birth weight- and gestational age-specific comparisons of perinatal mortality. Comparisons of neonatal mortality among very preterm and very low-birth-weight infants are plagued by incorrect denominators, and this leads to paradoxical findings.

SUMMARY

A lack of standardization with regard to birth registration and inadequate appreciation of the methods for calculating gestational age-specific mortality rates are responsible for biasing international comparisons of perinatal mortality.

Causes and temporal changes in nationally collected stillbirth audit data in high-resource settings

Few high-income countries have an active national programme of stillbirth audit. From the three national programmes identified (UK, New Zealand, and the Netherlands) steady declines in annual stillbirth rates have been observed over the audit period between 1993 and 2014. Unexplained stillbirth remains the largest group in the classification of stillbirths, with a decline in intrapartum-related stillbirths, which could represent improvements in intrapartum care. All three national audits of stillbirths suggest that up to half of all reviewed stillbirths have elements of care that failed to follow standards and guidance. Variation in the classification of stillbirth, cause of death and frequency of risk factor groups limit our ability to draw meaningful conclusions as to the true scale of the burden and the changing epidemiology of stillbirths in high-income countries. International standardization of these would facilitate direct comparisons between countries. The observed declines in stillbirth rates over the period of perinatal audit, a possible consequence of recommendations for improved antenatal care, should serve to incentivise other countries to implement similar audit programmes.

Perinatal outcomes in multifetal pregnancy following fetal reduction

BACKGROUND

There is currently insufficient evidence regarding the prognosis of multifetal pregnancy following elective fetal reduction to twin or singleton pregnancy. We compared perinatal outcomes in pregnancies with and without fetal reduction.

METHODS

We used data on all stillbirths and live births in British Columbia, Canada, from 2009 to 2013. We compared outcomes of multifetal pregnancies with fetal reduction (to twin or singleton pregnancy) with outcomes of pregnancies without fetal reduction. The primary outcome was a composite of serious neonatal morbidity or perinatal death. Other outcomes studied included preterm birth, low birth weight and small-for-gestational-age live birth.

RESULTS

The rate of serious neonatal morbidity or perinatal death did not differ significantly between pregnancies reduced to twins and unreduced triplet pregnancies (adjusted rate ratio 0.50, 95% confidence interval [CI] 0.24-1.07) or between pregnancies reduced to singletons and unreduced twin pregnancies (adjusted rate ratio 1.57, 95% CI 0.74-3.33). The rate was significantly lower in the fetal reduction group reduced to twins versus unreduced triplet pregnancies when we restricted the analysis to pregnancies conceived following the use of assisted reproduction technologies (adjusted rate ratio 0.35, 95% CI 0.18-0.67). The rates of preterm birth, very preterm birth, low birth weight and very low birth weight were significantly lower among pregnancies reduced to twins than among unreduced triplet pregnancies. Compared with unreduced twin pregnancies, pregnancies reduced to singletons had lower rates of preterm birth and low birth weight.

INTERPRETATION

Fetal reduction to twins and singletons was not associated with a decreased risk of serious neonatal morbidity or perinatal death. However, such fetal reduction was associated with substantial improvements in several other perinatal outcomes, such as preterm birth and low birth weight. Clinicians discussing the risks associated with multifetal pregnancy should counsel parents on the potential risks and benefits of fetal reduction.

Factors associated with fresh stillbirths: A hospital-based, matched, case-control study in Burkina Faso

OBJECTIVE

To determine the risk factors for fresh stillbirths in hospitals in Burkina Faso.

METHODS

A hospital-based, matched (1:1), case-control study was conducted from July to August 2014 in 50 hospitals across the country. All cases of stillbirth that occurred during this period in the participating facilities were included, and an appropriate control was selected for each case from the same health facility. Cases and controls were matched for gestational age. Conditional logistic regression with robust standard errors was used to compute both unadjusted and adjusted conditional odds ratios.

RESULTS

Cases were 67% less likely to have been delivered by a midwife compared with a nonmidwife attendant (ACOR=0.33; 95% CI, 0.12-0.84; P=0.02). Use of a partograph to monitor labor lowered the odds of fresh stillbirth by 82% (ACOR=0.18; 95% CI, 0.05-0.61; P=0.006). Mothers who had been transferred from another health facility were five times more likely to experience a fresh stillbirth (ACOR=5.36; 95% CI, 2.02-14.23; P<0.001).

CONCLUSION

Quality and timing of intrapartum obstetric care is key to preventing fresh stillbirths. Easy to implement and available interventions, such as use of a partograph for all laboring women and improving the referral system, have the potential to save the lives of many fetuses.

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.

Sex Ratios Among Births in British Columbia, 2000-2013

OBJECTIVE

Previous studies have reported distorted sex ratios among live births within specific immigrant groups in Canada. We carried out an investigation into sex ratios in British Columbia.

METHODS

All stillbirths and live births to residents of British Columbia from April 2000 to March 2013 were included in the study, with data obtained from the British Columbia Perinatal Data Registry. We examined sex ratios among births and among pregnancy terminations that resulted in a stillbirth or live birth. Analyses were stratified by congenital anomaly status, maternal residence, and parity.

RESULTS

The study population included 567 225 stillbirths and live births. In the Fraser Health Authority, the sex ratio among births without congenital anomalies was 51.3% males (95% CI 51.1 to 51.5); this was significantly higher than the sex ratio of 40.7% males (95% CI 33.2 to 48.6) among late pregnancy terminations without congenital anomalies (P = 0.008). However, in British Columbia, excluding the Fraser Health Authority, the same sex ratios were 51.1% (95% CI 50.9 to 51.3) and 51.1% (95% CI 45.5 to 56.7), respectively (P = 0.99). Sex ratios among births to multiparous women were also significantly different in the Fraser Health Authority. Only a negligible fraction of the shortfall in female births in the Fraser Health Authority could be explained by sex ratio distortions among late pregnancy terminations.

CONCLUSION

Sex ratios among stillbirths and live births to residents of the Fraser Health Authority are distorted relative to those observed elsewhere in British Columbia. This is likely due to sex differences in early pregnancy terminations.

Effect of Folic Acid Food Fortification in Canada on Congenital Heart Disease Subtypes

BACKGROUND

Previous studies have yielded inconsistent results for the effects of periconceptional multivitamins containing folic acid and of folic acid food fortification on congenital heart defects (CHDs).

METHODS

We carried out a population-based cohort study (N=5 901 701) of all live births and stillbirths (including late-pregnancy terminations) delivered at ≥20 weeks' gestation in Canada (except Québec and Manitoba) from 1990 to 2011. CHD cases were diagnosed at birth and in infancy (n=72 591). We compared prevalence rates and temporal trends in CHD subtypes before and after 1998 (the year that fortification was mandated). An ecological study based on 22 calendar years, 14 geographic areas, and Poisson regression analysis was used to quantify the effect of folic acid food fortification on nonchromosomal CHD subtypes (n=66 980) after controlling for changes in maternal age, prepregnancy diabetes mellitus, preterm preeclampsia, multiple birth, and termination of pregnancy.

RESULTS

The overall birth prevalence rate of CHDs was 12.3 per 1000 total births. Rates of most CHD subtypes decreased between 1990 and 2011 except for atrial septal defects, which increased significantly. Folic acid food fortification was associated with lower rates of conotruncal defects (adjusted rate ratio [aRR], 0.73, 95% confidence interval [CI], 0.62-0.85), coarctation of the aorta (aRR, 0.77; 95% CI, 0.61-0.96), ventricular septal defects (aRR, 0.85; 95% CI, 0.75-0.96), and atrial septal defects (aRR, 0.82; 95% CI, 0.69-0.95) but not severe nonconotruncal heart defects (aRR, 0.81; 95% CI, 0.65-1.03) and other heart or circulatory system abnormalities (aRR, 0.98; 95% CI, 0.89-1.11).

CONCLUSIONS

The association between food fortification with folic acid and a reduction in the birth prevalence of specific CHDs provides modest evidence for additional benefit from this intervention.

Feasibility of Implementing a Standardized Clinical Performance Indicator to Evaluate the Quality of Obstetrical Care in British Columbia

OBJECTIVES

To establish the feasibility of implementing a previously-published clinical standardized performance indicator, the Adverse Outcome Index (AOI), using routinely-collected data in a population-based perinatal database and to examine variation in the indicator over time and between hospitals.

METHODS

Maternal and newborn medical record data contained in the British Columbia Perinatal Data Registry, 2004-2013, were used to calculate an AOI (a composite of 10 maternal and newborn adverse events) and its severity-weighted scores, the Weighted Adverse Outcome Score and the Severity Index. Temporal trends in the indices were examined by plotting annual risks and weighted risks with 95% confidence intervals. Hospital-level risks were calculated with 95% confidence intervals, adjusting for patient case-mix.

RESULTS

Among 410,054 singleton deliveries in British Columbia, the risk of AOI was 5.8 per 100, while the Weighted Adverse Outcome Score and Severity Index were 1.6 and 27.4, respectively. The risk of AOI did not change significantly over the study period, while the Severity Index decreased from 29.3 (95% CI 26.7-31.9) in 2004 to 23.9 (22.0-25.8) in 2013. Fifteen of 52 hospitals had risks of AOI significantly above the provincial median. The hospitals' risks of AOI were not correlated with their Severity Indices (r = 0.02).

CONCLUSIONS

The AOI can successfully be estimated using data from a population-based database, and used to monitor trends in safety of labour and delivery over time and between hospitals. The low correlation between frequency and severity of adverse events confirms the importance of considering event severity in perinatal population health surveillance.

Stillbirths: recall to action in high-income countries

Variation in stillbirth rates across high-income countries and large equity gaps within high-income countries persist. If all high-income countries achieved stillbirth rates equal to the best performing countries, 19,439 late gestation (28 weeks or more) stillbirths could have been avoided in 2015. The proportion of unexplained stillbirths is high and can be addressed through improvements in data collection, investigation, and classification, and with a better understanding of causal pathways. Substandard care contributes to 20-30% of all stillbirths and the contribution is even higher for late gestation intrapartum stillbirths. National perinatal mortality audit programmes need to be implemented in all high-income countries. The need to reduce stigma and fatalism related to stillbirth and to improve bereavement care are also clear, persisting priorities for action. In high-income countries, a woman living under adverse socioeconomic circumstances has twice the risk of having a stillborn child when compared to her more advantaged counterparts. Programmes at community and country level need to improve health in disadvantaged families to address these inequities.

Declines in stillbirth and neonatal mortality rates in Europe between 2004 and 2010: results from the Euro-Peristat project

Background

Stillbirth and neonatal mortality rates declined in Europe between 2004 and 2010. We hypothesised that declines might be greater for countries with higher mortality in 2004 and disproportionally affect very preterm infants at highest risk.

Methods

Data about live births, stillbirths and neonatal deaths by gestational age (GA) were collected using a common protocol by the Euro-Peristat project in 2004 and 2010. We analysed stillbirths at ≥28 weeks GA in 22 countries and live births ≥24 weeks GA for neonatal mortality in 18 countries. Per cent changes over time were assessed by calculating risk ratios (RR) for stillbirth, neonatal mortality and preterm birth rates in 2010 vs 2004. We used meta-analysis techniques to derive pooled RR using random-effects models overall, by GA subgroups and by mortality level in 2004.

Results

Between 2004 and 2010, stillbirths declined by 17% (95% CI 10% to 23%), with a range from 1% to 39% by country. Neonatal mortality declined by 29% (95% CI 23% to 35%) with a range from 9% to 67%. Preterm birth rates did not change: 0% (95% CI −3% to 3%). Mortality declines were of a similar magnitude at all GA; mortality levels in 2004 were not associated with RRs.

Conclusions

Stillbirths and neonatal deaths declined at all gestational ages in countries with both high and low levels of mortality in 2004. These results raise questions about how low-mortality countries achieve continued declines and highlight the importance of improving care across the GA spectrum.

Differences in perinatal and infant mortality in high-income countries: artifacts of birth registration or evidence of true differences?

Background

Variation in birth registration criteria may compromise international comparisons of fetal and infant mortality. We examined the effect of birth registration practices on fetal and infant mortality rates to determine whether observed differences in perinatal and infant mortality rates were artifacts of birth registration or reflected true differences in health status.

Methods

A retrospective population-based cohort study was done using data from Canada, United States, Denmark, Finland, Iceland, Norway, and Sweden from 1995–2005. Main outcome measures included live births by gestational age and birth weight; gestational age—and birth weight-specific stillbirth rates; neonatal, post-neonatal, and cause-specific infant mortality.

Results

Proportion of live births <22 weeks varied substantially: Sweden (not reported), Iceland (0.00 %), Finland (0.001 %), Denmark (0.01 %), Norway (0.02 %), Canada (0.07 %) and United States (0.08 %). At 22–23 weeks, neonatal mortality rates were highest in Canada (892.2 per 1000 live births), Denmark (879.3) and Iceland (1000.0), moderately high in the United States (724.1), Finland (794.3) and Norway (739.0) and low in Sweden (561.2). Stillbirth:live birth ratios at 22–23 weeks were significantly lower in the United States (79.2 stillbirths per 100 live births) and Finland (90.8) than in Canada (112.1), Iceland (176.2) and Norway (173.9). Crude neonatal mortality rates were 83 % higher in Canada and 96 % higher in the United States than Finland. Neonatal mortality rates among live births ≥28 weeks were lower in Canada and United States compared with Finland. Post-neonatal mortality rates were higher in Canada and United States than in Nordic countries.

Conclusions

Live birth frequencies and stillbirth and neonatal mortality patterns at the borderline of viability are likely due to differences in birth registration practices, although true differences in maternal, fetal and infant health cannot be ruled out. This study emphasises the need for further standardisations, in order to enhance the relevance of international comparisons of infant mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0430-8) contains supplementary material, which is available to authorized users.

Cesarean Section and Subsequent Stillbirth, Is Confounding by Indication Responsible for the Apparent Association? An Updated Cohort Analysis of a Large Perinatal Database

BACKGROUND

Several studies and a recent meta-analysis have suggested that previous Cesarean section may increase the risk of stillbirth in a subsequent pregnancy. Given the high rates of Cesarean section in contemporary obstetric practice, this is of considerable public health importance. We sought to evaluate the potential that this association is the result of residual confounding bias.

METHODS

A large perinatal database (Alberta Perinatal Health Project) was searched to identify a matched set of first and second births from the years 1992-2006. Data on pregnancy outcomes, demographics and potential confounding factors were obtained.

RESULTS

The cohort was comprised of 98538 matched first and second births. Multivariate analysis did not reveal an association between previous Cesarean section and stillbirth, OR = 1.38 (0.98, 1.93). Restricting the analysis to a low risk group further attenuated the association, OR = .99 (0.62, 1.52). Analysis of the risk by indication for Cesarean section found that the risk was not increased for previous dystocia, OR = .91 (0.53, 1.55) nor for breech presentation, OR = 1.06 (0.50, 2.28) but only for other indications including non reassuring fetal status and fetal distress, OR = 1.96 (1.29, 2.98).

CONCLUSIONS

The results of our cohort analysis suggest that previous Cesarean section does not cause an increased risk of stillbirth.

Impact of pre-pregnancy diabetes mellitus on congenital anomalies, Canada, 2002-2012

OBJECTIVE

To examine the impact of pre-pregnancy diabetes mellitus (DM) on the population birth prevalence of congenital anomalies in Canada.

METHODS

We carried out a population-based study of all women who delivered in Canadian hospitals (except those in the province of Quebec) between April 2002 and March 2013 and their live-born infants with a birth weight of 500 grams or more and/or a gestational age of 22 weeks or more. Pre-pregnancy type 1 or type 2 DM was identified using ICD-10 diagnostic codes. The association between DM and all congenital anomalies as well as specific congenital anomaly categories was estimated using adjusted odds ratios; the impact was calculated as a population attributable risk percent (PAR%).

RESULTS

There were 118,892 infants with a congenital anomaly among 2,839,680 live births (41.9 per 1000). While the prevalence of any congenital anomaly declined from 50.7 per 1000 live births in 2002/03 to 41.5 per 1000 in 2012/13, the corresponding PAR% for a congenital anomaly related to pre-pregnancy DM rose from 0.6% (95% confidence interval [CI]: 0.4-0.8) to 1.2% (95% CI: 0.9-1.4). Specifically, the PAR% for congenital cardiovascular defects increased from 2.3% (95% CI: 1.7-2.9) to 4.2% (95% CI: 3.5-4.9) and for gastrointestinal defects from 0.8% (95% CI: 0.2-1.9) to 1.4% (95% CI: 0.7-2.6) over the study period.

CONCLUSION

Although there has been a relative decline in the prevalence of congenital anomalies in Canada, the proportion of congenital anomalies due to maternal pre-pregnancy DM has increased. Enhancement of preconception care initiatives for women with DM is recommended.

Disparities in treatment rates of paediatric end-stage renal disease across Europe: insights from the ESPN/ERA-EDTA registry

BACKGROUND

Considerable disparities exist in the provision of paediatric renal replacement therapy (RRT) across Europe. This study aims to determine whether these disparities arise from geographical differences in the occurrence of renal disease, or whether country-level access-to-care factors may be responsible.

METHODS

Incidence was defined as the number of new patients aged 0-14 years starting RRT per year, between 2007 and 2011, per million children (pmc), and was extracted from the ESPN/ERA-EDTA registry database for 35 European countries. Country-level indicators on macroeconomics, perinatal care and physical access to treatment were collected through an online survey and from the World Bank database. The estimated effect is presented per 1SD increase for each indicator.

RESULTS

The incidence of paediatric RRT in Europe was 5.4 cases pmc. Incidence decreased from Western to Eastern Europe (-1.91 pmc/1321 km, P < 0.0001), and increased from Southern to Northern Europe (0.93 pmc/838 km, P = 0.002). Regional differences in the occurrence of specific renal diseases were marginal. Higher RRT treatment rates were found in wealthier countries (2.47 pmc/€10 378 GDP per capita, P < 0.0001), among those that tend to spend more on healthcare (1.45 pmc/1.7% public health expenditure, P < 0.0001), and among countries where patients pay less out-of-pocket for healthcare (-1.29 pmc/11.7% out-of-pocket health expenditure, P < 0.0001). Country neonatal mortality was inversely related with incidence in the youngest patients (ages 0-4, -1.1 pmc/2.1 deaths per 1000 births, P = 0.10). Countries with a higher incidence had a lower average age at RRT start, which was fully explained by country GDP per capita.

CONCLUSIONS

Inequalities exist in the provision of paediatric RRT throughout Europe, most of which are explained by differences in country macroeconomics, which limit the provision of treatment particularly in the youngest patients. This poses a challenge for healthcare policy makers in their aim to ensure universal and equal access to high-quality healthcare services across Europe.

[Epidemiology of loss pregnancy]

OBJECTIVES

Study of epidemiology of pregnancy loss.

MATERIALS AND METHOD

A systematic review of the literature was performed using Pubmed and the Cochrane library databases and the guidelines from main international societies.

RESULTS

The occurrence of first trimester miscarriage is 12% of pregnancies and 25% of women. Miscarriage risk factors are ages of woman and man, body mass index greater than or equal to 25kg/m(2), excessive coffee drinking, smoking and alcohol consumption, exposure to magnetic fields and ionizing radiation, history of abortion, some fertility disorders and impaired ovarian reserve. Late miscarriage (LM) complicates less than 1% of pregnancies. Identified risk factors are maternal age, low level of education, living alone, history of previous miscarriage, of premature delivery and of previous termination of pregnancy, any uterine malformation, trachelectomy, existing bacterial vaginosis, amniocentesis, a shortened cervix and a dilated cervical os with prolapsed membranes. Fetal death in utero has a prevalence of 2% in the world and 5/1000 in France. Its main risk factors are detailed in the chapter.

Increased congenital heart defects in children born to women with systemic lupus erythematosus: results from the offspring of Systemic Lupus Erythematosus Mothers Registry Study

BACKGROUND

In a large population-based study, we aimed to determine whether children born to women with systemic lupus erythematosus (SLE) have an increased risk of congenital heart defects (CHDs) in comparison with children born to women without SLE.

METHODS AND RESULTS

The Offspring of SLE Mothers Registry (OSLER) includes all women who had ≥1 hospitalization for delivery after SLE diagnosis, identified through Quebec's healthcare databases (1989-2009), and a randomly selected control group of women, matched ≥4:1 for age and year of delivery. We identified children born live to SLE mothers and their matched controls, and ascertained CHD based on ≥1 hospitalization or physician visit with relevant diagnostic codes, within the first 12 months of life. We performed multivariable logistic regression analyses, using the generalized estimating equation method, to adjust for relevant covariates. Five hundred nine women with SLE had 719 children, whereas 5824 matched controls had 8493 children. In comparison with controls, children born to women with SLE experienced more CHD (5.2% [95% confidence interval (CI), 3.7-7.1] versus 1.9% [95% CI, 1.6-2.2], difference 3.3% [95% CI, 1.9-5.2]). In multivariable analyses, children born to women with SLE had a substantially increased risk of CHD (odds ratio, 2.62; 95% CI, 1.77-3.88) in comparison with controls. In addition, in comparison with controls, offspring of SLE mothers had a substantially increased risk of having a CHD repair procedure (odds ratio, 5.82; 95% CI, 1.77-19.09).

CONCLUSIONS

In comparison with children from the general population, children born to women with SLE have an increased risk of CHD, and an increased risk of having a CHD repair procedure, as well.

Trends and recurrence of stillbirths in NSW

OBJECTIVE

To examine the trend in stillbirth rates adjusted for the trends in the maternal risk profile, and to use local data to estimate the stillbirth recurrence risk.

METHODS

Linked hospital, birth and perinatal death review data were used to identify risk factors and stillbirths among women giving birth to singletons in NSW between 2001 and 2009. Logistic regression models were developed to predict stillbirth rates based on the changes in the maternal population.

RESULTS

Between 2001 and 2009 there were 3,449 stillbirths (4.4 per 1,000 births), with no significant change in rate overall (p=0.6) or across older gestational age categories (26-33 weeks p=0.67, ≥34 weeks p=0.36), and a slight increase at <26 weeks (p=0.01). However, when changes in the maternal population were taken into account, there was a significant increase in stillbirths at <26 weeks (p<0.001). Women with a stillbirth in a first pregnancy were at increased risk of stillbirth in their second pregnancy (4.3 95%CI 2.4-7.7).

CONCLUSION

There has been no decline in the stillbirth rate in NSW in recent years, which, at late gestations, may be accounted for by changes in the maternal population. At early gestations, there has been an increase in stillbirths where a decrease in rate may be expected based on the maternal population.

IMPLICATIONS

Further focus on addressing risk factors for stillbirths is needed to ensure continued progress is made in reducing stillbirths.

Association between maternal chronic conditions and congenital heart defects: a population-based cohort study

BACKGROUND

This study quantifies the association between maternal medical conditions/illnesses and congenital heart defects (CHDs) among infants.

METHODS AND RESULTS

We carried out a population-based study of all mother-infant pairs (n=2,278,838) in Canada (excluding Quebec) from 2002 to 2010 using data from the Canadian Institute for Health Information. CHDs among infants were classified phenotypically through a hierarchical grouping of International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Canada codes. Maternal conditions such as multifetal pregnancy, diabetes mellitus, hypertension, and congenital heart disease were defined by use of diagnosis codes. The association between maternal conditions and CHDs and its subtypes was modeled using logistic regression with adjustment for maternal age, parity, residence, and other factors. There were 26 488 infants diagnosed with CHDs at birth or at rehospitalization in infancy; the overall CHD prevalence was 116.2 per 10,000 live births, of which the severe CHD rate was 22.3 per 10,000. Risk factors for CHD included maternal age ≥40 years (adjusted odds ratio [aOR], 1.48; 95% confidence interval [CI], 1.39-1.58), multifetal pregnancy (aOR, 4.53; 95% CI, 4.28-4.80), diabetes mellitus (type 1: aOR, 4.65; 95% CI, 4.13-5.24; type 2: aOR, 4.12; 95% CI, 3.69-4.60), hypertension (aOR, 1.81; 95% CI, 1.61-2.03), thyroid disorders (aOR, 1.45; 95% CI, 1.26-1.67), congenital heart disease (aOR, 9.92; 95% CI, 8.36-11.8), systemic connective tissue disorders (aOR, 3.01; 95% CI, 2.23-4.06), and epilepsy and mood disorders (aOR, 1.41; 95% CI, 1.16-1.72). Specific CHD subtypes were associated with different maternal risk factors.

CONCLUSIONS

Several chronic maternal medical conditions, including diabetes mellitus, hypertension, connective tissue disorders, and congenital heart disease, confer an increased risk of CHD in the offspring.