Dataset Information

Variations in very preterm birth rates in 30 high-income countries: are valid international comparisons possible using routine data?

ABSTRACT:

Objective

Concerns about differences in registration practices across countries have limited the use of routine data for international very preterm birth (VPT) rate comparisons.

Design

Population-based study.

Setting

Twenty-seven European countries, the United States, Canada and Japan in 2010.

Population

A total of 9 376 252 singleton births.

Method

We requested aggregated gestational age data on live births, stillbirths and terminations of pregnancy (TOP) before 32 weeks of gestation, and information on registration practices for these births. We compared VPT rates and assessed the impact of births at 22-23 weeks of gestation, and different criteria for inclusion of stillbirths and TOP on country rates and rankings.

Main outcome measures

Singleton very preterm birth rate, defined as singleton stillbirths and live births before 32 completed weeks of gestation per 1000 total births, excluding TOP if identifiable in the data source.

Results

Rates varied from 5.7 to 15.7 per 1000 total births and 4.0 to 11.9 per 1000 live births. Country registration practices were related to percentage of births at 22-23 weeks of gestation (between 1% and 23% of very preterm births) and stillbirths (between 6% and 40% of very preterm births). After excluding births at 22-23 weeks, rate variations remained high and with a few exceptions, country rankings were unchanged.

Conclusions

International comparisons of very preterm birth rates using routine data should exclude births at 22-23 weeks of gestation and terminations of pregnancy. The persistent large rate variations after these exclusions warrant continued surveillance of VPT rates at 24 weeks and over in high-income countries.

Tweetable abstract

International comparisons of VPT rates should exclude births at 22-23 weeks of gestation and terminations of pregnancy.

SUBMITTER: Delnord M

PROVIDER: S-EPMC5346062 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Variations in very preterm birth rates in 30 high-income countries: are valid international comparisons possible using routine data?

Delnord M M Hindori-Mohangoo A D AD Smith L K LK Szamotulska K K Richards J L JL Deb-Rinker P P Rouleau J J Velebil P P Zile I I Sakkeus L L Gissler M M Morisaki N N Dolan S M SM Kramer M R MR Kramer M S MS Zeitlin J J

BJOG : an international journal of obstetrics and gynaecology 20160910 5

<h4>Objective</h4>Concerns about differences in registration practices across countries have limited the use of routine data for international very preterm birth (VPT) rate comparisons.<h4>Design</h4>Population-based study.<h4>Setting</h4>Twenty-seven European countries, the United States, Canada and Japan in 2010.<h4>Population</h4>A total of 9 376 252 singleton births.<h4>Method</h4>We requested aggregated gestational age data on live births, stillbirths and terminations of pregnancy (TOP) bef ...[more]

PMID: 27613083

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Project description:Meconium constitutes infants' first bowel movements postnatally. The consistency and microbial load of meconium are different from infant and adult stool. While recent evidence suggests that meconium is sterile in utero, rapid colonization occurs after birth. The meconium microbiome has been associated with negative health outcomes, but its composition is not well described, especially in preterm infants. Here, we characterized the meconium microbiomes from 330 very preterm infants (gestational ages 28 to 32 weeks) from 15 hospitals in Germany and in fecal samples from a subset of their mothers (N = 217). Microbiome profiles were compiled using 16S rRNA gene sequencing with negative and positive controls. The meconium microbiome was dominated by Bifidobacterium, Staphylococcus, and Enterococcus spp. and was associated with gestational age at birth and age at sample collection. Bifidobacterial abundance was negatively correlated with potentially pathogenic genera. The amount of bacterial DNA in meconium samples varied greatly across samples and was associated with the time since birth but not with gestational age or hospital site. In samples with low bacterial load, human mitochondrial sequences were highly amplified using commonly used, bacterial-targeted 16S rRNA primers. Only half of the meconium samples contained sufficient bacterial material to study the microbiome using a standard approach. To facilitate future meconium studies, we present a five-level scoring system ("MecBac") that predicts the success of 16S rRNA bacterial sequencing for meconium samples. These findings provide a foundational characterization of an understudied portion of the human microbiome and will aid the design of future meconium microbiome studies. IMPORTANCE Meconium is present in the intestines of infants before and after birth and constitutes their first bowel movements postnatally. The consistency, composition and microbial load of meconium is largely different from infant and adult stool. While recent evidence suggests that meconium is sterile in utero, rapid colonization occurs after birth. The meconium microbiome has been associated with short-term and long-term negative health outcomes, but its composition is not yet well described, especially in preterm infants. We provide a characterization of the microbiome structure and composition of infant meconium and maternal feces from a large study cohort and propose a method to evaluate meconium samples for bacterial sequencing suitability. These findings provide a foundational characterization of an understudied portion of the human microbiome and will aid the design of future meconium microbiome studies.

Dataset Information

Variations in very preterm birth rates in 30 high-income countries: are valid international comparisons possible using routine data?

Objective

Design

Setting

Population

Method

Main outcome measures

Results

Conclusions

Tweetable abstract

Publications

Variations in very preterm birth rates in 30 high-income countries: are valid international comparisons possible using routine data?

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