Newborn Cross-Sectional Study Research Articles

Comparison of updated birth weight, length and head circumference charts by gestational age in China with the INTERGROWTH-21st NCSS charts: a population-based study

BackgroundINTERGROWTH-21st Newborn Cross-Sectional Study (NCSS) charts were established and recommended for global application. However, whether one international reference is appropriate for all populations is still unclear. We aim to compare the updated Chinese birth size charts by gestational age with INTERGROWTH-21st NCSS charts.MethodsA cross-sectional survey was carried out, and the birth weight, length and head circumference of 24,375 infants born after uncomplicated pregnancies at gestational age ranging from 24+0 to 42+6 weeks were measured in 13 cities in China from 2015 to 2018. Growth charts were constructed. The measurements of all these infants were evaluated by the methods of calculating their Z scores using the INTERGROWTH-21st standards. The prevalence of small for gestational age (SGA) and large for gestational age (LGA) based on birth weight was analyzed using Chinese charts and INTERGROWTH-21st charts.ResultsThe mean Z scores were 0.10 for birth weight, 0.35 for length and − 0.02 for head circumference. Compared to the INTERGROWTH-21st charts, the Chinese birth weight percentile curves were higher except for the 90th percentile at 29–37 weeks gestational age, and the length percentile curves were higher after 33 weeks gestational age, while the 10th percentile of the head circumference was lower and the other percentiles were similar. The prevalence of SGA was 10.1% [95% confidence interval (CI) = 9.7%–10.5%] using the Chinese birth weight chart and 6.5% (95% CI = 6.2%–6.8%) using the INTERGROWTH-21st birth weight chart. The prevalence of LGA was 9.9% (95% CI = 9.5%–10.2%) and 8.2% (95% CI = 7.9%–8.6%) using the Chinese and INTERGROWTH-21st birth weight charts, respectively.ConclusionsChinese birth size charts based on infants born after uncomplicated pregnancies were different from the INTERGROWTH-21st charts. Differences in the classification of newborns by the two charts should receive attention, and whether the application of INTERGROWTH-21st in Chinese newborns will lead to misclassification needs to be validated in future clinical practice.

The distribution of clinical phenotypes of preterm birth syndrome: implications for prevention.

Preterm birth has been difficult to study and prevent because of its complex syndromic nature. To identify phenotypes of preterm delivery syndrome in the Newborn Cross-Sectional Study of the INTERGROWTH-21st Project. A population-based, multiethnic, cross-sectional study conducted at 8 geographically demarcated sites in Brazil, China, India, Italy, Kenya, Oman, the United Kingdom, and the United States. A total of 60,058 births over a 12-month fixed period between April 27, 2009, and March 2, 2014. Of these, 53,871 had an ultrasonography estimate of gestational age, among which 5828 were preterm births (10.8%). Pregnancies were prospectively studied using a standardized data collection and online data management system. Newborns had anthropometric and clinical examinations using standardized methods and identical equipment and were followed up until hospital discharge. The main study outcomes were clusters of preterm phenotypes and for each cluster, we analyzed signs of presentation at hospital admission, admission rates for neonatal intensive care for 7 days or more, and neonatal mortality rates. Twelve preterm birth clusters were identified using our conceptual framework. Eleven consisted of combinations of conditions known to be associated with preterm birth, 10 of which were dominated by a single condition. However, the most common single cluster (30.0% of the total preterm cases; n = 1747) was not associated with any severe maternal, fetal, or placental condition that was clinically detectable based on the information available; within this cluster, many cases were caregiver initiated. Only 22% (n = 1284) of all the preterm births occurred spontaneously without any of these severe conditions. Maternal presentation on hospital admission, newborn anthropometry, and risk for death before hospital discharge or admission for 7 or more days to a neonatal intensive care unit, none of which were used to construct the clusters, also differed according to the identified phenotypes. The prevalence of preterm birth ranged from 8.2% in Muscat, Oman, and Oxford, England, to 16.6% in Seattle, Washington. We identified 12 preterm birth phenotypes associated with different patterns of neonatal outcomes. In 22% of all preterm births, parturition started spontaneously and was not associated with any of the phenotypic conditions considered. We believe these results contribute to an improved understanding of this complex syndrome and provide an empirical basis to focus research on a more homogenous set of phenotypes.

International standards for newborn weight, length, and head circumference by gestational age and sex: the Newborn Cross-Sectional Study of the INTERGROWTH-21st Project

In 2006, WHO published international growth standards for children younger than 5 years, which are now accepted worldwide. In the INTERGROWTH-21(st) Project, our aim was to complement them by developing international standards for fetuses, newborn infants, and the postnatal growth period of preterm infants. INTERGROWTH-21(st) is a population-based project that assessed fetal growth and newborn size in eight geographically defined urban populations. These groups were selected because most of the health and nutrition needs of mothers were met, adequate antenatal care was provided, and there were no major environmental constraints on growth. As part of the Newborn Cross-Sectional Study (NCSS), a component of INTERGROWTH-21(st) Project, we measured weight, length, and head circumference in all newborn infants, in addition to collecting data prospectively for pregnancy and the perinatal period. To construct the newborn standards, we selected all pregnancies in women meeting (in addition to the underlying population characteristics) strict individual eligibility criteria for a population at low risk of impaired fetal growth (labelled the NCSS prescriptive subpopulation). Women had a reliable ultrasound estimate of gestational age using crown-rump length before 14 weeks of gestation or biparietal diameter if antenatal care started between 14 weeks and 24 weeks or less of gestation. Newborn anthropometric measures were obtained within 12 h of birth by identically trained anthropometric teams using the same equipment at all sites. Fractional polynomials assuming a skewed t distribution were used to estimate the fitted centiles. We identified 20,486 (35%) eligible women from the 59,137 pregnant women enrolled in NCSS between May 14, 2009, and Aug 2, 2013. We calculated sex-specific observed and smoothed centiles for weight, length, and head circumference for gestational age at birth. The observed and smoothed centiles were almost identical. We present the 3rd, 10th, 50th, 90th, and 97th centile curves according to gestational age and sex. We have developed, for routine clinical practice, international anthropometric standards to assess newborn size that are intended to complement the WHO Child Growth Standards and allow comparisons across multiethnic populations. Bill & Melinda Gates Foundation.

The likeness of fetal growth and newborn size across non-isolated populations in the INTERGROWTH-21st Project: the Fetal Growth Longitudinal Study and Newborn Cross-Sectional Study

Large differences exist in size at birth and in rates of impaired fetal growth worldwide. The relative effects of nutrition, disease, the environment, and genetics on these differences are often debated. In clinical practice, various references are often used to assess fetal growth and newborn size across populations and ethnic origins, whereas international standards for assessing growth in infants and children have been established. In the INTERGROWTH-21(st) Project, our aim was to assess fetal growth and newborn size in eight geographically defined urban populations in which the health and nutrition needs of mothers were met and adequate antenatal care was provided. For this study, fetal growth and newborn size were measured in two INTERGROWTH-21(st) component studies using prespecified markers and the same methods, equipment, and selection criteria. In the Fetal Growth Longitudinal Study (FGLS), we studied educated, affluent, healthy women, with adequate nutritional status who were at low risk of intrauterine growth restriction. The primary markers of fetal growth were ultrasound measurements of fetal crown-rump length at less than 14 weeks and 0 days of gestation and fetal head circumference from 14 weeks and 0 days to 40 weeks and 0 days of gestation, and birthlength for newborn size. In the concomitant, population-based Newborn Cross-Sectional Study (NCSS), we measured birthlength in all newborn babies from the eight geographically defined urban populations with the same methods, instruments, and staff as in FGLS. From this large NCSS cohort, we selected an FGLS-like subpopulation to match FGLS with the same eligibility criteria. Between May 14, 2009, and Aug 2, 2013, we enrolled 4607 women in FGLS and 59 137 women in NCSS. From NCSS, 20 486 (34·6%) women met the FGLS eligibility criteria, and constituted the FGLS-like subpopulation. With variance component analysis, only between 1·9% and 3·5% of the total variability in crown-rump length, fetal head circumference, and newborn birthlength could be attributed to between-site differences. With standardised site effect analysis in 16 gestational age windows from 9 weeks and 0 days of gestation to birth for the three measures (128 comparisons), only one was marginally higher than 0·5 SD of the standardised site difference range. Sensitivity analyses, excluding individual populations in turn from the pooling of all-site centiles across gestational ages, showed no noticeable effect on the 3rd, 50th, and 97th centiles derived from the remaining populations. Our populations were consistent at birth with those in the WHO Multicentre Growth Reference Study (MGRS). The mean birthlength for term newborn babies in that study was 49·5 cm (SD 1·9), which was very similar to that in the FGLS cohort (49·4 cm [1·9]) and the NCSS derived FGLS-like subpopulation (49·3 cm [1·8]). Fetal growth and newborn length are similar across diverse geographical settings when mothers' nutritional and health needs are met, and environmental constraints on growth are low. The findings for birthlength are in strong agreement with those of the WHO MGRS. These results provide the conceptual frame to create international standards for growth from conception to newborn baby, which will extend the present infant to childhood WHO MGRS standards. Bill & Melinda Gates Foundation.

Implementation of the INTERGROWTH‐21st Project in the United States

The North American site in the INTERGROWTH‐21st Project was North Seattle, Washington State, USA. The majority of the data were collected from within Seattle City, which has approximately 12 300 births per year. The sample for the Newborn Cross‐Sectional Study (NCSS) was drawn from two hospitals (Swedish Medical Center and the University of Washington) covering almost 80% of deliveries within the target population. The Fetal Growth Longitudinal Study (FGLS) sample was recruited from several antenatal clinics serving the University of Washington Medical Center and Providence Everett Medical Center. Special activities to encourage participation and raise awareness of the studies included furnishing the recruitment sites with fliers designed by the Project Coordinating Unit, and presenting the studies to clinical staff to encourage providers to refer appropriate patients. One of the major challenges at this site was the low recruitment rate in the early phase of the FGLS because of the high rates of smoking, maternal age >35 years and body mass index >30 years. This was remedied by the inclusion of other ancillary clinics, as well as increased advertising among the general public.

Implementation of the INTERGROWTH‐21st Project in Italy

Turin, Italy, was one of the two European sites for the INTERGROWTH-21(st) Project. The sample for the Newborn Cross-Sectional Study (NCSS) was drawn from two obstetric hospitals that together account for 79% of the city's approximately 12,000 births per year. Women were recruited for the Fetal Growth Longitudinal Study (FGLS) from ten antenatal clinics serving the city's largest obstetric hospital, Azienda Ospedaliera OIRM-S. Anna. Special activities to encourage participation and raise awareness of the project in this population included obtaining an endorsement from the coordinator of the city's antenatal care service, and disseminating information about the project to women through posters and leaflets in antenatal clinics. One of the major challenges at this site was the low recruitment rate in the early phase of FGLS because of the high prevalence of smoking and of women >35 years old in the population. The addition of six extra recruiting clinics served to increase the pool of potentially eligible women who could be screened and led to a marked improvement in the recruitment rate.

Implementation of the INTERGROWTH‐21stProject in India

The South Asian site in the INTERGROWTH-21(st) Project was the city of Nagpur, in Maharashtra State, India, with approximately 4500 births per year among the target population with middle to high socio-economic status. These deliveries are mainly concentrated in 20 small private hospitals, most of which are in the city centre. The sample for the Newborn Cross-Sectional Study (NCSS) was drawn from ten of these hospitals, covering 76% of the target low-risk pregnant population. The Fetal Growth Longitudinal Study (FGLS) sample was recruited from the largest of these institutions, Ketkar Hospital, as well as several ancillary antenatal care clinics. Special activities to encourage participation and raise awareness of the study at this site included translating patient information leaflets into local languages and securing local media interest. Among the unique challenges of the Indian site was the coordination of the large number of hospitals involved in NCSS, a task that required careful planning and organisation by the field teams.

Statistical considerations for the development of prescriptive fetal and newborn growth standards in theINTERGROWTH‐21stProject

The INTERGROWTH-21(st) Project has in its mandate to develop prescriptive standards for fetal, neonatal and preterm post-neonatal growth. The project comprises three components: the Fetal Growth Longitudinal Study (FGLS), the Preterm Postnatal Follow-up Study (PPFS), and the Newborn Cross-Sectional Study (NCSS). We consider here the statistical aspects of the three components as they relate to the construction of these standards, in particular the sample size, and outline the principles that will guide the planned main analyses.

Implementation of the INTERGROWTH‐21stProject in Oman

The Middle Eastern site in the INTERGROWTH‐21st Project was Muscat, the capital city of Oman, with approximately 10 500 births per year. The sample for the Newborn Cross‐Sectional Study (NCSS) was drawn from two hospitals covering 96% of the region's births. The Fetal Growth Longitudinal Study (FGLS) sample was recruited from four primary health facilities serving Khoula Hospital, using the eligibility criteria in the INTERGROWTH‐21st protocol. Special activities to encourage participation in this population included local advocacy campaigns to encourage early antenatal booking and ultrasound dating in the population. The major challenges at the site were the recruitment of sufficient numbers of women at an early gestational age, and the timely measurement of all newborns within 12 hours of birth. Many individuals and institutions collaborated effectively over a period of several years on these studies, which required careful planning and close monitoring for their successful implementation.

Implementation of the INTERGROWTH‐21st Project in Brazil

Please cite this paper as: Silveira M, Barros F, Sclowitz I, Domingues M, Mota D, Fonseca S, Mitidieri A, Leston A, Knight H, Cheikh Ismail L, for the International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH‐21st). Implementation of the INTERGROWTH‐21st Project in Brazil. BJOG 2013; 120 (Suppl. 2): 81–86.The Latin American site in the INTERGROWTH‐21st Project was Pelotas, Brazil, with approximately 4000 births per year. The sample for the Newborn Cross‐Sectional Study (NCSS) was drawn from four hospitals, covering 99% of births in the city. The Fetal Growth Longitudinal Study (FGLS) sample was recruited from one of the largest private ultrasound clinics in the city and 30 smaller, private, antenatal clinics serving middle to high socio‐economic status women. Among this site’s major challenges was the recruitment of women for FGLS from numerous different clinics. Several public relations activities were conducted to improve collaborative efforts between the research team and obstetricians, paediatricians and community leaders in Pelotas.

Implementation of the INTERGROWTH‐21st Project in China

Please cite this paper as: Pan Y, Wu M, Wang J, Pang R, Knight H, Cheikh Ismail L, for the International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH‐21st). Implementation of the INTERGROWTH‐21st Project in China. BJOG 2013; 120 (Suppl. 2): 87–93.The East Asian site in the INTERGROWTH‐21st Project was Shunyi County, Beijing, China, which is an affluent suburb of north Beijing delivering approximately 7000 women annually. The Newborn Cross‐Sectional Study (NCSS) sample was drawn from two hospitals, covering >85% of births in the county. The Fetal Growth Longitudinal Study sample (FGLS) was recruited from the antenatal clinic of Shunyi Maternal & Child Health Hospital, the larger of the two institutions. Special activities to promote the study in this population included: (1) the distribution of health education materials about the importance of antenatal care and (2) the organisation of seminars by the study team to brief key stakeholders at the two hospitals about the goals of the research. One of the major challenges at this site in the early stages of the study was a reluctance to have an early ultrasound dating scan (<14+0 weeks of gestation). This challenge was overcome after a thorough evaluation of the literature regarding the benefits of an early ultrasound scan for dating purposes, as a result of which there was a formal change in hospital policy.

Implementation of the INTERGROWTH‐21st Project in Kenya

The African site in the INTERGROWTH-21(st) Project was Parklands, a wealthy suburb of Nairobi, Kenya, with a largely middle-to-high socio-economic status population. There are three hospitals with obstetric units in Parklands, with approximately 4300 births per year. The Newborn Cross-Sectional Study (NCSS) sample was drawn from all three hospitals, covering 100% of births in this target population. The Fetal Growth Longitudinal Study (FGLS) sample was recruited from antenatal clinics serving these hospitals, using the eligibility criteria in the INTERGROWTH-21(st) protocol. Special activities to raise awareness of the study included securing media coverage and distributing leaflets in antenatal clinic waiting rooms. FGLS required women to be recruited in the first trimester; therefore, a major challenge at this study site was the high background frequency of first antenatal consultations in the second trimester. The problem was overcome by the study awareness campaign, as a result of which more women started attending antenatal care earlier in pregnancy.

Implementation of the INTERGROWTH‐21st Project in the UK

Please cite this paper as: Roseman F, Knight H, Giuliani F, Lloyd S, Di Nicola P, Laister A, Roseman S, Kennedy K, Burnham O, Patel B, Puglia F, Blakey I, Cheikh Ismail L, for the International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH‐21st). Implementation of the INTERGROWTH‐21st Project in the UK. BJOG 2013; 120 (Suppl. 2): 117–122.There are approximately 10 000 births per year in the county of Oxfordshire in the UK, which is one of the two European sites for the International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH‐21st) Project. The samples for both components of the project – the Fetal Growth Longitudinal Study (FGLS) and Newborn Cross‐Sectional Study (NCSS) – were drawn from the John Radcliffe Hospital, a major university hospital with a large regional role that covers more than 75% of deliveries in the county. Special activities to encourage participation in this population included the formation of a research coalition to streamline recruitment in the Maternity Unit and the distribution of study information leaflets to women using the hospital’s antenatal care service. This was a demanding project and several challenges were overcome to reach recruitment targets and to maintain high standards of data quality. Amongst the major challenges for FGLS at this study site was the level of ineligibility because of maternal age, smoking and body mass index (BMI) ≥ 30. The major challenge for the NCSS field teams was to ensure that all anthropometric data were collected before the early discharge of uncomplicated deliveries, often within 6 hours of birth. It is evident from our experience in implementing this project that, when large‐scale clinical studies are meticulously planned and avoid major disruption to routine clinical care, they are well received by hospital staff and can contribute to the improvement of the overall standard of clinical care.