Impact of stillbirths on international comparisons of preterm birth rates: a secondary analysis of the WHO multi-country survey of Maternal and Newborn Health

Perinatal loss in Tanzania: Perspectives of maternal-child healthcare providers

Over 98% of stillbirths and neonatal deaths occur in Low- and Middle-Income Countries, such as Tanzania. Despite the profound burden of perinatal loss in these regions, access to facility or community-based palliative and psychosocial care is poor and understudied. In this study we explore perinatal loss through the lens of front-line healthcare providers, to better understand the knowledge and beliefs that guide their engagement with bereaved families. A Knowledge Attitudes and Practices survey addressing perinatal loss in Tanzania was developed, translated into Swahili, and administered over a 4-month period to healthcare professionals working at the Kilimanjaro Christian Medical Center (KCMC). Results were entered into REDCap and analyzed in R Studio. 74 providers completed the survey. Pediatric providers saw a yearly average of 5 stillbirths and 32.7 neonatal deaths. Obstetric providers saw an average of 11.5 stillbirths and 13.12 neonatal deaths. Most providers would provide resuscitation beginning at 28 weeks gestational age. Respondents estimated that a 50% chance of survival for a newborn occurred at 28 weeks both nationally and at KCMC. Most providers felt that stillbirth and neonatal mortality were not the mother's fault (78.4% and 81.1%). However, nearly half (44.6%) felt that stillbirth reflects negatively on the woman and 62.2% agreed that women are at higher risk of abuse or abandonment after stillbirth. A majority perceived that women wanted hold their child after stillbirth (63.0%) or neonatal death (70.3%). Overall, this study found that providers at KCMC perceived that women are at greater risk of psychosocial or physical harm following perinatal loss. How women can best be supported by both the health system and their community remains unclear. More research on perinatal loss and bereavement in LMICs is needed to inform patient-level and health-systems interventions addressing care gaps unique to resource-limited or non-western settings.

National, regional, and global estimates of preterm birth in 2020, with trends from 2010: a systematic analysis

BACKGROUND

Preterm birth is the leading cause of neonatal mortality and is associated with long-term physical, neurodevelopmental, and socioeconomic effects. This study updated national preterm birth rates and trends, plus novel estimates by gestational age subgroups, to inform progress towards global health goals and targets, and aimed to update country, regional, and global estimates of preterm birth for 2020 in addition to trends between 2010 and 2020.

METHODS

We systematically searched population-based, nationally representative data on preterm birth from Jan 1, 2010, to Dec 31, 2020 and study data (26 March-14 April, 2021) for countries and areas with no national-level data. The analysis included 679 data points (86% nationally representative administrative data [582 of 679 data points]) from 103 countries and areas (62% of countries and areas having nationally representative administrative data [64 of 103 data points]). A Bayesian hierarchical regression was used for estimating country-level preterm rates, which incoporated country-specific intercepts, low birthweight as a covariate, non-linear time trends, and bias adjustments based on a data quality categorisation, and other indicators such as method of gestational age estimation.

FINDINGS

An estimated 13·4 million (95% credible interval [CrI] 12·3-15·2 million) newborn babies were born preterm (<37 weeks) in 2020 (9·9% of all births [95% CrI 9·1-11·2]) compared with 13·8 million (12·7-15·5 million) in 2010 (9·8% of all births [9·0-11·0]) worldwide. The global annual rate of reduction was estimated at -0·14% from 2010 to 2020. In total, 55·6% of total livebirths are in southern Asia (26·8% [36 099 000 of 134 767 000]) and sub-Saharan Africa (28·7% [38 819 300 of 134 767 000]), yet these two regions accounted for approximately 65% (8 692 000 of 13 376 200) of all preterm births globally in 2020. Of the 33 countries and areas in the highest data quality category, none were in southern Asia or sub-Saharan Africa compared with 94% (30 of 32 countries) in high-income countries and areas. Worldwide from 2010 to 2020, approximately 15% of all preterm births occurred at less than 32 weeks of gestation, requiring more neonatal care (<28 weeks: 4·2%, 95% CI 3·1-5·0, 567 800 [410 200-663 200 newborn babies]); 28-32 weeks: 10·4% [9·5-10·6], 1 392 500 [1 274 800-1 422 600 newborn babies]).

INTERPRETATION

There has been no measurable change in preterm birth rates over the last decade at global level. Despite increasing facility birth rates and substantial focus on routine health data systems, there remain many missed opportunities to improve preterm birth data. Gaps in national routine data for preterm birth are most marked in regions of southern Asia and sub-Saharan Africa, which also have the highest estimated burden of preterm births. Countries need to prioritise programmatic investments to prevent preterm birth and to ensure evidence-based quality care when preterm birth occurs. Investments in improving data quality are crucial so that preterm birth data can be improved and used for action and accountability processes.

FUNDING

The Children's Investment Fund Foundation and the UNDP, United Nations Population Fund-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction.

Machine learning-based placental clusters and their associations with adverse pregnancy outcomes

BACKGROUND

Placental abnormalities have been described in clinical convenience samples, with predominately adverse outcomes. Few studies have described placental patterns in unselected samples.

OBJECTIVE

We aimed to investigate associations between co-occurring placental features and adverse pregnancy outcomes in a prospective cohort of singletons.

METHODS

Data were from the Safe Passage study (U.S. and South Africa, 2007-2015). Before 24 weeks' gestation, participants were randomly invited to donate placental tissue at delivery for blinded, standardised pathological examination. We used hierarchical clustering to construct statistically derived groups using 60 placental features. We estimated associations between the placental clusters and select adverse pregnancy outcomes, expressed as unadjusted and adjusted risk ratios (RRs) and robust 95% confidence intervals (CI).

RESULTS

We selected a 7-cluster model. After collapsing 2 clusters to form the reference group, we labelled the resulting 6 analytic clusters according to the overarching category of their most predominant feature(s): severe maternal vascular malperfusion (n = 117), fetal vascular malperfusion (n = 222), other vascular malperfusion (n = 516), inflammation 1 (n = 269), inflammation 2 (n = 175), and normal (n = 706). Risks for all outcomes were elevated in the severe maternal vascular malperfusion cluster. For instance, in unadjusted analyses, this cluster had 12 times the risk of stillbirth (RR 12.07, 95% CI 4.20, 34.68) and an almost doubling in the risk of preterm delivery (RR 1.93, 95% CI 1.27, 2.93) compared with the normal cluster. Small infant size was more common among the abnormal clusters, with the highest unadjusted RRs observed in the fetal vascular malperfusion cluster (small for gestational age birth RR 2.99, 95% CI 2.24, 3.98, head circumference <10th percentile RR 2.86, 95% CI 1.60, 5.12). Upon adjustment for known risk factors, most RRs attenuated but remained >1.

CONCLUSION

Our study adds to the growing body of epidemiologic research, finding adverse pregnancy outcomes may occur through etiologic mechanisms involving co-occurring placental abnormalities.

Investigation of stillbirths in Brazil: A systematic scoping review of the causes and related reporting processes in the past decade

BACKGROUND

Recognizing the causes of stillbirths and their associated conditions is essential to reduce its occurrence.

OBJECTIVE

To describe information on stillbirths in Brazil during the past decade.

SEARCH STRATEGY

A literature search was performed from January 2010 to December 2020.

SELECTION CRITERIA

Original observational studies and clinical trials.

DATA COLLECTION AND ANALYSIS

Data were manually extracted to a spreadsheet and descriptive analysis was performed.

RESULTS

A total of 55 studies were included; 40 studies (72.2%) used the official data stored by national public health systems. Most articles aimed to estimate the rate and trends of stillbirth (60%) or their causes (55.4%). Among the 16 articles addressing the causes of death, 10 (62.5%) used the International Classification of Diseases; most of the articles only specified the main cause of death. Intrauterine hypoxia was the main cause reported (ranging from 14.3% to 54.9%).

CONCLUSION

Having a national system based on compulsory notification of stillbirths may not be sufficient to provide quality information on occurrence and, especially, causes of death. Further improvements of the attribution and registration of causes of deaths and the implementation of educational actions for improving reporting systems are advisable. Finally, expanding the investigation of contributing factors associated with stillbirths would create an opportunity for further development of prevention strategies in low- and middle-income countries such as Brazil.

Adverse pregnancy and perinatal outcomes in Latin America and the Caribbean: systematic review and meta-analysis

Objective.

To estimate the point prevalence and likely ranges of pregnancy-induced hypertension, pre-eclampsia, gestational diabetes, low birth weight and preterm delivery in Latin America and the Caribbean, and evaluate the heterogeneity of the estimates.

Methods.

We conducted a systematic review and meta-analysis of observational studies reporting the prevalence of maternal and perinatal adverse outcomes in populations in Latin American and the Caribbean published between 2000 and 2019 in English, Spanish, or Portuguese. We searched PubMed, Embase, and LILACS. We estimated the point prevalence and evaluated overall heterogeneity and, in sub-group analyses, heterogeneity by study design and level of bias.

Results.

Of 1087 records retrieved, 50 articles were included in the review: two on hypertensive disorders of pregnancy, 14 on pre-eclampsia, six on gestational diabetes, nine on low birth weight and 19 on preterm birth. No meta-analysis for hypertensive disorders of pregnancy could be done because of the small number of studies. Point prevalence estimates and 95% confidence intervals (CIs) for pre-eclampsia, gestational diabetes, low birth weight, and preterm birth were: 6.6% (95% CI: 4.9%, 8.6%), 8.5% (95% CI: 3.9%, 14.7%), 8.5% (95% CI: 7.2%, 9.8%), and 10.0% (95% CI: 8.0%, 12.0%), respectively. We observed substantial heterogeneity overall and by study design. No major differences in estimates were observed by level of bias.

Conclusions.

The results of this study provide updated estimates of some of the most prevalent adverse pregnancy and perinatal outcomes in Latin America and the Caribbean. They highlight that important heterogeneity exists in prevalence estimates, which may reflect the diversity of populations in the region.

Increase in preterm stillbirths in association with reduction in iatrogenic preterm births during COVID-19 lockdown in Australia: a multicenter cohort study

Background

The COVID-19 pandemic has been associated with a worsening of perinatal outcomes in many regions around the world. Melbourne, Australia, had one of the longest and most stringent lockdowns worldwide in 2020 while recording only rare instances of COVID-19 infection in pregnant women.

Objective

This study aimed to compare the stillbirth and preterm birth rates in women who were exposed or unexposed to lockdown restrictions during pregnancy.

Study Design

This was a retrospective, multicenter cohort study of perinatal outcomes in Melbourne before and during the COVID-19 lockdown. The lockdown period was defined as the period from March 23, 2020 to March 14, 2021. Routinely-collected maternity data on singleton pregnancies ≥24 weeks gestation without congenital anomalies were obtained from all the 12 public hospitals in Melbourne. We defined the lockdown-exposed cohort as those women for whom weeks 20 to 40 of gestation occurred during the lockdown and the unexposed control group as women from the corresponding calendar periods 12 and 24 months before. The main outcome measures were stillbirth, preterm birth, fetal growth restriction (birthweight < third centile), and iatrogenic preterm birth for fetal compromise. We performed multivariable logistic regression analysis to compare the odds of stillbirth, preterm birth, fetal growth restriction, and iatrogenic preterm birth for fetal compromise, adjusting for multiple covariates.

Results

There were 24,817 births in the exposed group and 50,017 births in the control group. There was a significantly higher risk of preterm stillbirth in the exposed group than the control group (0.26% vs 0.18%; adjusted odds ratio, 1.49; 95% confidence interval, 1.08–2.05; P=.015). There was also a significant reduction in the preterm birth of live infants <37 weeks (5.68% vs 6.07%; adjusted odds ratio, 0.93; 95% confidence interval, 0.87–0.99; P=.02), which was largely mediated by a significant reduction in iatrogenic preterm birth (3.01% vs 3.27%; adjusted odds ratio, 0.91; 95% confidence interval, 0.83–0.99; P=.03), including iatrogenic preterm birth for fetal compromise (1.25% vs 1.51%; adjusted odds ratio, 0.82; 95% confidence interval, 0.71–0.93; P=.003). There were also significant reductions in special care nursery admissions during lockdown (11.53% vs 12.51%; adjusted odds ratio, 0.90; 95% confidence interval, 0.86–0.95; P<.0001). There was a trend to fewer spontaneous preterm births <37 weeks in the exposed group of a similar magnitude to that reported in other countries (2.69% vs 2.82%; adjusted odds ratio, 0.95; 95% confidence interval, 0.87–1.05; P=.32).

Conclusion

Lockdown restrictions in Melbourne, Australia were associated with a significant reduction in iatrogenic preterm birth for fetal compromise and a significant increase in preterm stillbirths. This raises concerns that pandemic conditions in 2020 may have led to a failure to identify and appropriately care for pregnant women at an increased risk of antepartum stillbirth. Further research is required to understand the relationship between these 2 findings and to inform our ongoing responses to the pandemic.

Erythropoietin as a Neuroprotective Drug for Newborn Infants: Ten Years after the First Use

Protective strategies against perinatal brain injury represent a major challenge for modern neonatology. Erythropoietin (Epo) enhances endogenous mechanisms of repair and angiogenesis. In order to analyse the newest evidence on the role of Epo in prematurity, hypoxic ischemic encephalopathy (HIE) and perinatal stroke, a critical review using 2020 PRISMA statement guidelines was conducted. This review uncovered 26 clinical trials examining the use of Epo for prematurity and brain injury-related outcomes. The effects of Epo on prematurity were analysed in 16 clinical trials. Erythropoietin was provided until 32–35 weeks of corrected postnatal age with a dosage between 500–3000 UI/kg/dose. Eight trials reported the Epo effects on HIE term newborn infants: Erythropoietin was administered in the first weeks of life, at different multiple doses between 250–2500 UI/kg/dose, as either an adjuvant therapy with hypothermia or a substitute for hypothermia. Two trials investigated Epo effects in perinatal stroke. Erythropoietin was administered at a dose of 1000 IU/kg for three days. No beneficial effect in improving morbidity was observed after Epo administration in perinatal stroke. A positive effect on neurodevelopmental outcome seems to occur when Epo is used as an adjuvant therapy with hypothermia in the HIE newborns. Administration of Epo in preterm infants still presents inconsistencies with regard to neurodevelopmental outcome. Clinical trials show significant differences mainly in target population and intervention scheme. The identification of specific markers and their temporal expression at different time of recovery after hypoxia-ischemia in neonates might be implemented to optimize the therapeutic scheme after hypoxic-ischemic injury in the developing brain. Additional studies on tailored regimes, accounting for the risk stratification of brain damage in newborns, are required.

Implementing an intrapartum package of interventions to improve quality of care to reduce the burden of preterm birth in Kenya and Uganda

Background

Quality of care during the intrapartum and immediate postnatal period for maternal and newborn health remains a major challenge due to the multiple health system bottlenecks in low-income countries. Reports of complex interventions that have been effective in reducing maternal and newborn mortality in these settings are usually limited in description, which inhibits learning and replication. We present a detailed account of the Preterm Birth Initiative (PTBi) implementation process, experiences and lessons learnt to inform scale-up and replication.

Methods

Using the TiDieR framework, we detail how the PTBi implemented an integrated package of interventions through a pair-matched cluster randomized control trial in 20 health facilities in Migori County, Kenya, and the Busoga region in east central Uganda from 2016 to 2019. The package aimed to improve quality of care during the intrapartum and immediate postnatal period with a focus on preterm birth. The package included data strengthening (DS) and introduction of a modified WHO Safe Childbirth Checklist (mSCC), simulation-based training and mentoring (PRONTO), and a Quality Improvement (QI) Collaborative.

Results

In 2016, DS and mSCC were introduced to improve existing data processes and increase the quality of data for measures needed to evaluate study impact. PRONTO and QI interventions were then rolled out sequentially. While package components were implemented with fidelity, some implementation processes required contextual adaptation to allow alignment with national priorities and guidelines, and flexibility to optimize uptake.

Conclusion

Lessons learned included the importance of synergy between interventions, the need for local leadership engagement, and the value of strengthening local systems and resources. Adaptations of individual elements of the package to suit the local context were important for effective implementation, and the TIDieR framework provides the guidance needed in detailed description to replicate such a complex intervention in other settings. Detailed documentation of the implementation process of a complex intervention with mutually synergistic components can help contextualize trial results and potential for scale-up. The trial is registered at ClinicalTrials.govNCT03112018, registered December 2016, posted April 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43058-021-00109-w.

Factors associated with risk of preterm delivery in Tanzania: A case-control study at Muhimbili National Hospital

OBJECTIVE

To determine factors associated with risk of preterm delivery among pregnant women delivering at Muhimbili National Hospital in Tanzania.

METHODS

A 1:1 case-control study was conducted to assess maternal sociodemographic, lifestyle, and current and previous obstetric factors associated with risk of preterm delivery. Mothers of preterm infants were regarded as cases and those of term infants were controls. Chi-square test and logistic regression were used to assess association between the factors and risk of preterm delivery.

RESULTS

A total of 222 case-control pairs were studied. Maternal type of employment (P = 0.039), previous preterm delivery (P = 0.002), previous spontaneous abortion (P = 0.004), uterine scar (P < 0.001), parity (P = 0.034), number of prenatal care visits (P = 0.032), premature rupture of membranes (PROM) (P < 0.001), placenta previa (P = 0.002), bleeding during second trimester (P = 0.004), pre-eclampsia (P < 0.001), and maternal anemia (P = 0.033) were associated with risk of preterm delivery. The main risk factors associated with preterm delivery included previous preterm delivery (odds ratio [OR] 13.23, 95% confidence interval [CI] 1.72-101.95), placenta previa (OR 12.63, 95% CI 1.63-97.98), and PROM (OR 8.77, 95% CI 1.33-4.60).

CONCLUSION

Close monitoring of pregnant women who present any of the risk factors is important to prevent or reduce the risk of preterm delivery in Tanzania.

Incidence and trend of preterm birth in China, 1990-2016: a systematic review and meta-analysis

OBJECTIVES

To update the WHO estimate of preterm birth rate in China in 1990-2016 and to further explore variations by geographic regions and years of occurrence.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Pubmed, Embase, Cochrane Library and Sinomed databases were searched from 1990 to 2018.

ELIGIBILITY CRITERIA

Studies were included if they provided preterm birth data with at least 500 total births. Reviews, case-control studies, intervention studies and studies with insufficient information or published before 1990 were excluded. We estimated pooled incidence of preterm birth by a random effects model, and preterm birth rate in different year, region and by livebirths or all births in subgroup analyses.

RESULTS

Our search identified 3945 records. After the removal of duplicates and screening of titles and abstracts, we reviewed 254 studies in full text and excluded 182, leaving 72 new studies. They were combined with the 82 studies included in the WHO report (154 studies, 187 data sets in total for the meta-analysis), including 24 039 084 births from 1990 to 2016. The pooled incidence of preterm birth in China was 6.09% (95% CI 5.86% to 6.31%) but has been steadily increasing from 5.36% (95% CI 4.89% to 5.84%) in 1990-1994 to 7.04% (95% CI 6.09% to 7.99%) in 2015-2016. The annual rate of increase was about 1.05% (95% CI 0.85% to 1.21%). Northwest China appeared to have the highest preterm birth rate (7.3%, 95% CI 4.92% to 9.68% from 1990 to 2016).

CONCLUSIONS

The incidence of preterm birth in China has been rising gradually in the past three decades. It was 7% in 2016. Preterm birth rate varied by region with the West having the highest occurrence.

Association between antenatal care visit and preterm birth: a cohort study in rural Bangladesh

BACKGROUND

Strengthening the antenatal care programme is suggested as one of the public health strategies to reduce preterm birth burden at a population level. However, the evidence so far available is inconclusive.

OBJECTIVES

To evaluate the association between antenatal care (ANC) visit and preterm birth; and also to explore to what extent the increased usage of ANC after the initiation of the Maternal, Neonatal and Child Health (MNCH) project in Matlab, Bangladesh, contributed to the reduction of preterm birth.

SETTING

This population-based cohort study was conducted in Matlab, a subdistrict under Chandpur. The analysis was based on data collected from 2005 to 2009. In 2007, an MNCH project was initiated in the area that strengthened the ongoing ANC services.

PARTICIPANTS

In total, 12 980 live births with their mothers during the study period were included in the analysis.

ANALYSIS

We performed logistic regression with generalised estimating equation models to evaluate the associations.

OUTCOME MEASURES

Preterm birth.

RESULTS

The number of ANC visits was associated with preterm birth in a dose-dependent way (p for linear trend <0.001). The adjusted odds of preterm birth were 2.4-times higher (OR 2.37, 95% CI 2.07 to 2.70) among women who received ≤1 ANC compared with women who received ≥3 ANC. We observed a significant reduction of preterm birth rates (OR 0.69, 95% CI 0.61 to 0.77) in the period after (2008 to 2009) MNCH project initiation in comparison to the period before (2005 to 2006). Controlling for ANC visits substantially attenuated this observed effect of the MNCH project on preterm birth (OR 0.88, 95% CI 0.77 to 0.99) (Sobel test of mediation p<0.001).

CONCLUSIONS

ANC visits are associated with decreased occurrences of preterm births. Strengthening the ANC services should be prioritised in countries with high preterm birth rates to reduce the preterm birth burden at the population level.

Cervical pessary plus vaginal progesterone versus long-term tocolysis for the prevention of preterm birth: An observational retrospective study

OBJECTIVE

To compare cervical pessaries plus vaginal progesterone versus long-term tocolysis for preventing preterm birth for women with a short cervix.

METHODS

Retrospective evaluation of women with singleton pregnancy who received cervical pessaries plus vaginal progesterone (combined group) or ritodrine hydrochloride (tocolysis group) for short cervix (≤25 mm at 20-24 weeks, or ≤20 mm at 25-34 weeks) at a general hospital in Kagoshima, Japan, 2015-2019. The primary outcome was rate of preterm birth (<36 weeks); secondary outcomes were maternal hospital admittance and treatment complications.

RESULTS

Data were evaluated from 95 women (combined group, n=43; tocolysis group, n=52). There was no significant difference in cervical length or gestational age at intervention between the groups. Overall, 3/43 (7.0%) women delivered before 36 weeks in the combined group versus 16/52 (30.8%) in the tocolysis group (relative risk, 0.56; 95% confidence interval, 0.41-0.76; P=0.004). Median maternal admittance was shorter in the combined group (6.6 vs 41.0 days, P<0.001). Although 36/43 (83.7%) women in the combined group reported increased vaginal discharge, no major complications occurred.

CONCLUSION

A combination of pessaries and vaginal progesterone reduced the rate of preterm birth (<36 weeks) for women with short cervix as compared with long-term tocolysis.

Safety of influenza vaccination on adverse birth outcomes among pregnant women: A prospective cohort study in Japan

BACKGROUND

Pregnant women are in the highest priority group for receiving influenza vaccination. However, they may be reluctant to receive the vaccination due to concerns about the influence of vaccination on the fetuses.

METHODS

This prospective cohort study of 10 330 pregnant women examined the safety of influenza vaccination in terms of adverse birth outcomes. Influenza vaccination during pregnancy was determined from questionnaires before and after the 2013/2014 influenza season. All subjects were followed until the end of their pregnancy. Adverse birth outcomes, including miscarriage, stillbirth, preterm birth, low birth weight, and malformation, were assessed by obstetrician reports.

RESULTS

Adverse birth outcomes were reported for 641 (10%) of the 6387 unvaccinated pregnant women and 356 (9%) of the 3943 vaccinated pregnant women. Even after adjusting for potential confounders, vaccination during pregnancy showed no association with the risk of adverse birth outcomes (odds ratio 0.90, 95% confidence interval 0.76-1.07). Vaccination during the first or second trimester displayed no association with adverse birth outcomes, whereas vaccination during the third trimester was associated with a decreased risk of adverse birth outcomes (odds ratio 0.70, 95% confidence interval 0.51-0.98).

CONCLUSIONS

Influenza vaccination during pregnancy did not increase the risk of adverse birth outcomes, regardless of the trimester in which vaccination was performed, when compared to unvaccinated pregnant women.

A Review of the Potential Benefits of Increasing Vitamin D Status in Mongolian Adults through Food Fortification and Vitamin D Supplementation

Serum 25-hydroxyvitamin D (25(OH)D) concentrations are low in Mongolia, averaging 22 ng/mL in summer and only 8 ng/mL in winter. Mongolians have high incidence and/or prevalence of several diseases linked to low 25(OH)D concentrations, including ischemic heart disease, malignant neoplasms, cirrhosis of the liver, ischemic stroke, lower respiratory tract infections, preterm birth complications, and diabetes mellitus. Fortifying regularly consumed foods such as flour, milk, and edible oils with vitamin D₃ could raise 25(OH)D concentrations by about 10 ng/mL. However, to achieve 25(OH)D concentrations of 30–40 ng/mL in adults, vitamin D intakes of 1000 to 4000 IU/day would be required, making personal supplement use necessary. On the basis of prospective observational studies and clinical trials of disease incidence or known mortality rates and adverse pregnancy and birth outcomes, raising mean serum 25(OH)D concentrations to 40 ng/mL would likely reduce incidence and mortality rates for those and other diseases, reduce the rate of adverse pregnancy and birth outcomes, and increase mean life expectancy by one year or more.

History of the establishment of the Preterm Birth international collaborative (PREBIC)

INTRODUCTION

The primary aim of PREBIC is to assess the underlying mechanisms and developing strategies for preterm birth (PTB) prevention.

MATERIALS AND METHODS

We used concept mapping and logic models to track goals. This paper reviews our progress over 13 years using working group activities, research developments, guest speakers, and publications.

RESULTS

Using interactions between genetics, environment, and behaviors we identified complex interactions between biological systems. PREBIC determined that epidemiology and biomarkers should be an initial focus. In 2005, we initiated presentations by young investigators, yearly satellite meetings, working groups including nutrition and inflammation, assessment of clinical trials, and accepted an invitation by the WHO to begin yearly meetings in Geneva.

DISCUSSION

PREBIC used epidemiology to identify PTB factors and complex pathways. Candidate genes are associated with the environment, behavior (stress), obesity, inflammation and insulin resistance. Epigenetic changes and production of proteins can be used as biomarkers to define risk. Subsequently, we found risk factors for PTB that were also associated with the risk of cardiovascular disease (CVD) of the mother. Tanz et al. (2017) found that a history of PTB is independently predictive of CVD later in life and suggested that a modest proportion of PTB-CVD association was accounted by CVD risk factors, many of which have been identified in this paper.

CONCLUSION

Our findings support a relationship between genes, environment, behaviors and risk of CVD in women. The next several years must assess which factors are modifiable early in life and before pregnancy to prevent PTB.

Epidemiology of late preterm and early term births - An international perspective

Late preterm (34-36 weeks of gestational age (GA)), and early term (37-38 weeks GA) birth rates among singleton live births vary from 3% to 6% and from 15% to 31%, respectively, across countries, although data from low- and middle-income countries are sparse. Countries with high preterm birth rates are more likely to have high early term birth rates; many risk factors are shared, including pregnancy complications (hypertension, diabetes), medical practices (provider-initiated delivery, assisted reproduction), maternal socio-demographic and lifestyle characteristics and environmental factors. Exceptions include nulliparity and inflammation which increase risks for preterm, but not early term birth. Birth before 39 weeks GA is associated with adverse child health outcomes across a wide range of settings. International rate variations suggest that reductions in early delivery are achievable; implementation of best practice guidelines for obstetrical interventions and public health policies targeting population risk factors could contribute to prevention of both late preterm and early term births.

Global, regional, and national estimates of levels of preterm birth in 2014: a systematic review and modelling analysis

BACKGROUND

Preterm birth is the leading cause of death in children younger than 5 years worldwide. Although preterm survival rates have increased in high-income countries, preterm newborns still die because of a lack of adequate newborn care in many low-income and middle-income countries. We estimated global, regional, and national rates of preterm birth in 2014, with trends over time for some selected countries.

METHODS

We systematically searched for data on preterm birth for 194 WHO Member States from 1990 to 2014 in databases of national civil registration and vital statistics (CRVS). We also searched for population-representative surveys and research studies for countries with no or limited CRVS data. For 38 countries with high-quality data for preterm births in 2014, data are reported directly. For countries with at least three data points between 1990 and 2014, we used a linear mixed regression model to estimate preterm birth rates. We also calculated regional and global estimates of preterm birth for 2014.

FINDINGS

We identified 1241 data points across 107 countries. The estimated global preterm birth rate for 2014 was 10·6% (uncertainty interval 9·0-12·0), equating to an estimated 14·84 million (12·65 million-16·73 million) live preterm births in 2014. 12· 0 million (81·1%) of these preterm births occurred in Asia and sub-Saharan Africa. Regional preterm birth rates for 2014 ranged from 13·4% (6·3-30·9) in North Africa to 8·7% (6·3-13·3) in Europe. India, China, Nigeria, Bangladesh, and Indonesia accounted for 57·9 million (41×4%) of 139·9 million livebirths and 6·6 million (44×6%) of preterm births globally in 2014. Of the 38 countries with high-quality data, preterm birth rates have increased since 2000 in 26 countries and decreased in 12 countries. Globally, we estimated that the preterm birth rate was 9×8% (8×3-10×9) in 2000, and 10×6% (9×0-12×0) in 2014.

INTERPRETATION

Preterm birth remains a crucial issue in child mortality and improving quality of maternal and newborn care. To better understand the epidemiology of preterm birth, the quality and volume of data needs to be improved, including standardisation of definitions, measurement, and reporting.

FUNDING

WHO and the March of Dimes.

Maternal mortality in Spain and its association with country of origin: cross-sectional study during the period 1999-2015

Background

The available literature suggests that there are significant differences in maternal mortality according to maternal origin in high income countries. The objective of this study was to quantify the risk of maternal death by maternal origin and region of Spain where the birth occurred and to identify the most important causes of maternal death in our country.

Methods

An ecological cross-sectional study was conducted that included all deliveries that resulted in maternal survival and cases of maternal death during 1999–2015 in Spain. A descriptive analysis of the maternal mortality rate by maternal origin, region and year of birth was performed. The risk of maternal death was calculated using univariate and multivariate logistic regression analysis, with adjustment for the variables included in the descriptive analysis.

Results

There were 272 maternal deaths during this period, most of which were due to haemorrhage (63 cases, 23.16%).Women whose continent of origin was South America had the highest adjusted risk of maternal death, with an OR of 3.92 (95% CI 2.75–5.58). The region of Spain with the highest risk of maternal death was Ceuta, with an OR of 12.11 (95% CI 2.02–72.68).

Conclusions

This study shows that there are inequalities in maternal mortality according to maternal origin and region where labour occurred. These findings highlight the need to establish strategies at the national and European levels to analyse the most relevant causes and risk factors associated with maternal mortality in order to reduce it and pay closer attention in identifying and carefully managing pregnant women from this at risk groups.

The project to understand and research preterm pregnancy outcomes and stillbirths in South Asia (PURPOSe): a protocol of a prospective, cohort study of causes of mortality among preterm births and stillbirths

Background

In South Asia, where most stillbirths and neonatal deaths occur, much remains unknown about the causes of these deaths. About one-third of neonatal deaths are attributed to prematurity, yet the specific conditions which cause these deaths are often unclear as is the etiology of stillbirths. In low-resource settings, most women are not routinely tested for infections and autopsy is rare.

Methods

This prospective, cohort study will be conducted in hospitals in Davengere, India and Karachi, Pakistan. All women who deliver either a stillbirth or a preterm birth at one of the hospitals will be eligible for enrollment. With consent, the participant and, when applicable, her offspring, will be followed to 28-days post-delivery. A series of research tests will be conducted to determine infection and presence of other conditions which may contribute to the death. In addition, all routine clinical investigations will be documented. For both stillbirths and preterm neonates who die ≤ 28 days, with consent, a standard autopsy as well as minimally invasive tissue sampling will be conducted. Finally, an expert panel will review all available data for stillbirths and neonatal deaths to determine the primary and contributing causes of death using pre-specified guidance.

Conclusion

This will be among the first studies to prospectively obtain detailed information on causes of stillbirth and preterm neonatal death in low-resource settings in Asia. Determining the primary causes of death will be important to inform strategies most likely to reduce the high mortality rates in South Asia.

Trial registration

Clinicaltrials.gov (NCT03438110) Clinical Trial Registry of India (CTRI/2018/03/012281).

Saúde reprodutiva, materna, neonatal e infantil nos 30 anos do Sistema Único de Saúde (SUS)

Resumo Este estudo apresenta um sumário das intervenções realizadas no âmbito do setor público e os indicadores de resultado alcançados na saúde de mulheres e crianças, destacando-se os avanços no período 1990-2015. Foram descritos indicadores de atenção pré-natal, assistência ao parto e saúde materna e infantil utilizando dados provenientes de Sistemas de Informação Nacionais de nascidos vivos e óbitos; inquéritos nacionais; e publicações obtidas de diversas outras fontes. Foram também descritos os programas governamentais desenvolvidos para a melhoria da saúde das mulheres e das crianças, bem como outros intersetoriais para redução da pobreza. Houve grande queda nas taxas de fecundidade, universalização da atenção pré-natal e hospitalar ao parto, aumento do acesso à contracepção e aleitamento materno, e diminuição das hospitalizações por aborto e da subnutrição. Mantém-se em excesso a sífilis congênita, taxa de cesarianas e nascimentos prematuros. A redução na mortalidade na infância foi de mais de 2/3, mas não tão marcada no componente neonatal. A razão de mortalidade materna decresceu de 143,2 para 59,7 por 1000 NV. Embora alguns poucos indicadores tenham demonstrado piora ou mantido a estabilidade, a grande maioria apresentou acentuadas melhoras.

Human Development Index (HDI) of the maternal country of origin as a predictor of perinatal outcomes - a longitudinal study conducted in Spain

Background

In an era of worldwide population displacement, recent studies have identified strong associations between social situations and perinatal outcomes among immigrants. Little is known about the effect of maternal social background on pregnancy outcomes. The Human Development Index (HDI) assesses the following dimensions of human development: life expectancy, education level and income. The objective of our study was to determine if maternal HDI may be used to identify women at increased odds of poor pregnancy outcomes.

Methods

We conducted a longitudinal population-based study in a tertiary centre in Madrid, Spain. The outcome variables were maternal and perinatal/antenatal mortality, preeclampsia (PE), low birth weight (LBW), gestational diabetes mellitus (GDM), preterm delivery (PTD) before 37 and 34 gestational weeks, abnormal cardiotocography (CTG) during delivery, C-section (CS) due to abnormal CTG, pH < 7.10 at birth, Apgar at 5 min ≤ 7, and resuscitation type ≥3. We performed multivariate logistic regression analyses adjusted for potential confounding variables to evaluate the associations between maternal HDI and perinatal outcomes.

Results

In total, 38,719 singleton infants who were born in our maternity ward between 2010 and 2016 and had perinatal outcome data available were included in this study. The neonates of women from medium/low HDI countries had significantly lower odds of low birth weight (LBW) than their very high HDI country counterparts (OR 0.63, 95% CI 0.55–0.72). However, the odds of PTD before 37 gestational weeks and PE were higher in the medium/low HDI group than the very high HDI group (OR 1.26, 95% CI 1.04–1.53; OR 1.35, 95% CI 1.02–1.79, respectively). Poorer neonatal outcomes were identified in the medium/low HDI group than the very high HDI group, including greater odds of abnormal CTG, CS due to abnormal CTG and Apgar 2 ≤ 7 (p < 0.05).

Conclusions

Our findings suggest that the infants of mothers from medium/low HDI had lower odds of LBW but higher odds of PTD, PE and poor neonatal outcomes. These results support the hypothesis that maternal HDI can be used to understand the impact of maternal origin on pregnancy outcomes. Further studies are needed to confirm its validity.

Provider-initiated delivery, late preterm birth and perinatal mortality: a secondary analysis of the WHO multicountry survey on maternal and newborn health

Introduction

In high-income countries, a reduced clinical threshold for obstetric interventions such as labour induction (LI) and prelabour caesarean delivery (PLCD) has played a substantial role in increasing rates of late preterm births. However, the association between provider-initiated delivery and perinatal outcomes have not been studied in a multicountry setting including low-income and middle-income countries.

Methods

286 hospitals in 29 countries participated in the WHO Multi-Country Survey on Maternal and Newborn Health and yielded 2 52 198 singleton births of at least 34 weeks in 2010–2011. We used an ecological analysis based on generalised estimating equations under multilevel logistic regression to estimate associations between hospital rates of PLCD and LI with rates of late preterm birth (34–36 weeks), stillbirth and intrahospital early neonatal death, in relation to country development based on the Human Development Index (HDI).

Results

Rates of LI were higher in hospitals from very high-HDI (median 10.9%) and high-HDI (11.2%) countries compared with medium-HDI (4.0%) or low-HDI (3.8%) countries. Rates of PLCD were by far the lowest in low-HDI countries compared with countries in the other three categories (5.1% vs 12.0%–17.9%). Higher rates of PLCD were associated with lower perinatal death rates (OR 0.87 (0.79, 0.95) per 5% increase in PLCD) and non-significantly with late preterm birth (1.04 (0.98, 1.10)) regardless of country development. LI rates were positively associated with late preterm birth (1.04 (1.01, 1.06)) regardless of country development and with perinatal death (1.06 (0.98, 1.15)) only in middle-HDI and low- HDI countries.

Conclusion

PLCD was associated with reduced perinatal mortality and non-significantly with increased late preterm birth. LI was associated with increases in both late preterm birth and, in less-developed countries, perinatal mortality. Efforts to provide sufficient, but avoid excessive, access to provider-initiated delivery should be tailored to the local context.

Impact of stillbirths on international comparisons of preterm birth rates: a secondary analysis of the WHO multi-country survey of Maternal and Newborn Health

Objective

To evaluate the extent to which stillbirths affect international comparisons of preterm birth rates in low‐ and middle‐income countries.

Design

Secondary analysis of a multi‐country cross‐sectional study.

Setting

29 countries participating in the World Health Organization Multicountry Survey on Maternal and Newborn Health.

Population

258 215 singleton deliveries in 286 hospitals.

Methods

We describe how inclusion or exclusion of stillbirth affect rates of preterm births in 29 countries.

Main outcome measures

Preterm delivery.

Results

In all countries, preterm birth rates were substantially lower when based on live births only, than when based on total births. However, the increase in preterm birth rates with inclusion of stillbirths was substantially higher in low Human Development Index (HDI) countries [median 18.2%, interquartile range (17.2–34.6%)] compared with medium (4.3%, 3.0–6.7%), and high‐HDI countries (4.8%, 4.4–5.5%).

Conclusion

Inclusion of stillbirths leads to higher estimates of preterm birth rate in all countries, with a disproportionately large effect in low‐HDI countries. Preterm birth rates based on live births alone do not accurately reflect international disparities in perinatal health; thus improved registration and reporting of stillbirths are necessary.

Tweetable abstract

Inclusion of stillbirths increases preterm birth rates estimates, especially in low‐HDI countries.

Inclusion of stillbirths increases preterm birth rates estimates, especially in low‐HDI countries.