The objectives, design and implementation of the INTERGROWTH‐21^st Project

Abstract

), with technical support from four global specialised units, to study growth, health and nutrition from early pregnancy to infancy. It aims to produce prescriptive growth standards, which conceptually extend the World Health Organization (WHO) Multicentre Growth Reference Study (MGRS) to cover fetal and newborn life. The new international standards will describe: (1) fetal growth assessed by clinical and ultrasound measures; (2) postnatal growth of term and preterm infants up to 2 years of age; and (3) the relationship between birthweight, length and head circumference, gestational age and perinatal outcomes. As the project has selected healthy cohorts with no obvious risk factors for intrauterine growth restriction, these standards will describe how all fetuses and newborns should grow, as opposed to traditional charts that describe how some have grown at a given place and time. These growth patterns will be related to morbidity and mortality to identify levels of perinatal risk. Additional aims include phenotypic characterisation of the preterm and impaired fetal growth syndromes and development of a prediction model, based on multiple ultrasound measurements, to estimate gestational age for use in pregnant women without access to early/frequent antenatal care.

The antepartum stillbirth syndrome: risk factors and pregnancy conditions identified from the INTERGROWTH‐21st Project

“…The primary aim was to study fetal growth and development from early pregnancy until 2 years of age 13. Populations were selected at the cluster level.…”

“…Within these sites, hospitals and clinics were selected to ensure coverage of at least 80% of births. All participating hospitals agreed to a policy of routinely estimating gestational age using ultrasound before 24 weeks’ gestation with a strict, standardised protocol to measure either fetal crown–rump length (if ≤14 weeks’ gestation) or head circumference (if >14 and ≤24 weeks’ gestation) 13. Information was obtained on all births from 16 weeks’ gestation.…”

“…Second, the association between stillbirth and SGA at birth, defined as birth weight <3rd centile for gestational age, and gender for babies born after 24 weeks using the INTERGROWTH‐21 st Newborn Size at Birth Standards, was assessed 25. Third, we evaluated the ultrasound growth trajectories for the stillbirths that occurred within the Fetal Growth Longitudinal Study (FGLS) of the INTERGROWTH‐21 st Project 13. A subset was selected of 4607 women who were at low risk, at the individual level, of growth problems at the start of pregnancy, and who were monitored with serial ultrasound scans every 5 weeks until delivery 26…”

International standards for symphysis-fundal height based on serial measurements from the Fetal Growth Longitudinal Study of the INTERGROWTH-21stProject: prospective cohort study in eight countries

“…INTERGROWTH-21 st was a multicentre, multiethnic, population based project, conducted between 2009 and 2014 in eight countries 35. The project’s primary aim was to study growth, health, nutrition, and neurodevelopment from less than 14 weeks’ gestation to 2 years of age, using the same conceptual framework as the World Health Organization Multicentre Growth Reference Study 36…”

Ethical issues arising from the INTERGROWTH‐21st Fetal Growth Longitudinal Study

“…The whole project is dependent for its very existence on the goodwill of almost 60 000 pregnant women from the populations involved, of whom approximately 4500 in the Fetal Growth Longitudinal Study (FGLS) were completely healthy and not in need of any special medical attention other than routine antenatal care. 2 In addition, INTERGROWTH-21 st relies upon the dedication of a vast number of committed professionals. Therefore, the purpose of the ethical framework was to ensure that the rights of all those involved were respected and acknowledged, and that the benefits of the project outweighed any present or future harm.…”