Variation in preterm birth rate and the role of short cervical length across two populations: a comparative cohort study

ObjectivesTo investigate time trends of preterm birth and estimate the contributions of risk factors to the changes in preterm birth rates over a decade (2009–2018) of transitional period in Shenzhen, China.DesignRetrospective cohort study between 2009 and 2018.SettingAll births in Baoan during January 2009 and December 2018 registered in the Shenzhen Birth Registry Database.Participants478 044 live births were included with sociodemographic and medical records for both women and infants.Outcome measuresThe incidence rate of preterm birth stratified by different maternal and infant characteristics. Multiple logistic regression was used to identify significant risk factors associated with preterm birth. The population attributable risk fraction of each factor was calculated to estimate its contribution to variations of preterm birth rate over the 10 years.ResultsA total of 27 829 preterm births from 478 044 (5.8%) live births were recorded and the preterm birth rate increased from 5.5% in 2009 to 6.2% in 2018. Medically induced preterm birth rate increased from 2.0% in 2009 to 3.4% in 2018 while spontaneous preterm labour rate decreased from 3.3% to 2.7% over the decade years. Risk factors including multiple pregnancy (0.28% increase) drove the rise of preterm birth rate, whereas changes in maternal educational attainment (0.22% reduction) and prenatal care utilisation (0.45% reduction) had contributed to the decline in preterm birth rate.ConclusionsAn uptrend of preterm birth rate was observed in an area under rapid sociodemographic transitions during 2009–2018 and the changes were associated with these sociodemographic transitions. Continued investments in girls’ education and prenatal care have the potential of reducing preterm birth rate.

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Validity of pre and post-term birth rates based on the date of last menstrual period compared to early obstetric ultrasonography

Cadernos de Saúde Pública ◽

10.1590/0102-311x00121514 ◽

2015 ◽

Vol 31 (4) ◽

pp. 885-890 ◽

Cited By ~ 2

Author(s):

Maria Nilza Lima Medeiros ◽

Nádia Carenina Nunes Cavalcante ◽

Fabrício José Alencar Mesquita ◽

Rosângela Lucena Fernandes Batista ◽

Vanda Maria Ferreira Simões ◽

...

Keyword(s):

Preterm Birth ◽

Positive Predictive Value ◽

Predictive Value ◽

Birth Rate ◽

Menstrual Period ◽

Last Menstrual Period ◽

Birth Rates ◽

Term Birth ◽

Preterm Birth Rate ◽

Obstetric Ultrasonography

The aim of this study was to assess the validity of the last menstrual period (LMP) estimate in determining pre and post-term birth rates, in a prenatal cohort from two Brazilian cities, São Luís and Ribeirão Preto. Pregnant women with a single fetus and less than 20 weeks' gestation by obstetric ultrasonography who received prenatal care in 2010 and 2011 were included. The LMP was obtained on two occasions (at 22-25 weeks gestation and after birth). The sensitivity of LMP obtained prenatally to estimate the preterm birth rate was 65.6% in São Luís and 78.7% in Ribeirão Preto and the positive predictive value was 57.3% in São Luís and 73.3% in Ribeirão Preto. LMP errors in identifying preterm birth were lower in the more developed city, Ribeirão Preto. The sensitivity and positive predictive value of LMP for the estimate of the post-term birth rate was very low and tended to overestimate it. LMP can be used with some errors to identify the preterm birth rate when obstetric ultrasonography is not available, but is not suitable for predicting post-term birth.

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Are COVID-19 mitigation measures reducing preterm birth rate in China?

BMJ Global Health ◽

10.1136/bmjgh-2021-006359 ◽

2021 ◽

Vol 6 (8) ◽

pp. e006359

Author(s):

Zheng Bian ◽

Xiaoxian Qu ◽

Hao Ying ◽

Xiaohua Liu

Keyword(s):

Preterm Birth ◽

Birth Rate ◽

Time Window ◽

Time Windows ◽

Mitigation Measures ◽

Late Preterm Birth ◽

Child Morbidity ◽

Preterm Birth Rate ◽

Underlying Mechanisms ◽

The Impact

ObjectivePreterm birth is the leading cause of child morbidity and mortality globally. We aimed to determine the impact of the COVID-19 mitigation measures implemented in China on 23 January 2020 on the incidence of preterm birth in our institution.DesignLogistic regression analysis was used to investigate the association between the national COVID-19 mitigation measures implemented in China and the incidence of preterm birth.SettingShanghai First Maternity and Infant Hospital, Shanghai China.ParticipantsAll singleton deliveries abstracted from electronic medical record between 1 January 2014 to 31 December 2020.Main outcome measuresPreterm birth rate.ResultsData on 164 107 singleton deliveries were available. COVID-19 mitigation measures were consistently associated with significant reductions in preterm birth in the 2-month, 3-month, 4-month, 5-month time windows after implementation (+2 months, OR 0.80, 95% CI 0.69 to 0.94; +3 months, OR 0.83, 95% CI 0.73 to 0.94; +4 months, OR 0.82, 95% CI 0.73 to 0.92; +5 months, OR 0.84, 95% CI 0.76 to 0.93). These reductions in preterm birth were obvious across various degrees of prematurity, but were statistically significant only in moderate-to-late preterm birth (32 complete weeks to 36 weeks and 6 days) subgroup. The preterm birth difference disappeared gradually after various restrictions were removed (7th–12th month of 2020, OR 1.02, 95% CI 0.94 to 1.11). There was no difference in stillbirth rate across the study time window.ConclusionSubstantial decreases in preterm birth rates were observed following implementation of the national COVID-19 mitigation measures in China. Further study is warranted to explore the underlying mechanisms associated with this observation.

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Place Matters: Variation in the Black/White Very Preterm Birth Rate across U.S. Metropolitan Areas, 2002–2004

Public Health Reports ◽

10.1177/003335490812300507 ◽

2008 ◽

Vol 123 (5) ◽

pp. 576-585 ◽

Cited By ~ 54

Author(s):

Michael R. Kramer ◽

Carol R. Hogue

Keyword(s):

Preterm Birth ◽

Birth Rate ◽

Metropolitan Areas ◽

Very Preterm ◽

Very Preterm Birth ◽

Preterm Birth Rate

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

BMJ Open ◽

10.1136/bmjopen-2020-039303 ◽

2020 ◽

Vol 10 (12) ◽

pp. e039303

Author(s):

Shiwen Jing ◽

Chang Chen ◽

Yuexin Gan ◽

Joshua Vogel ◽

Jun Zhang

Keyword(s):

Systematic Review ◽

Preterm Birth ◽

Birth Rate ◽

Meta Analysis ◽

Northwest China ◽

Cochrane Library ◽

Case Control Studies ◽

Eligibility Criteria ◽

Rate Of Increase ◽

Preterm Birth Rate

ObjectivesTo 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.DesignSystematic review and meta-analysis.Data sourcesPubmed, Embase, Cochrane Library and Sinomed databases were searched from 1990 to 2018.Eligibility criteriaStudies 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.ResultsOur 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).ConclusionsThe 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.

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