Helping Assess and Monitor Growth from the Womb to the Cradle

Last week, the first International Standards to assess fetal growth and newborn size worldwide were published in The Lancet. The standards were developed by the INTERGROWTH 21^st Project, a collaboration of over 300 clinicians and researchers from 27 institutions from across the world, including The Hospital for Sick Children (SickKids) in Toronto, Canada. The six-year landmark project was funded by the Bill & Melinda Gates Foundation.

Every baby is unique and the concept of ‘normal’ is fleeting in a global capacity, however the news standards allow health practitioners to monitor growth ‘from the womb to the cradle’ in the same way. The international standards – one for the growing fetus and the other for newborns – provide doctors and midwives with clinical tools that can be incorporated immediately into practice during pregnancy and at birth. Investigators used the same conceptual approach; study design and instrument measures as the World Health Organization (WHO) did in developing the existing International Growth Standards for children aged between 0 and 5.

The INTERGROWTH-21^st Project studied all pregnant women who delivered in selected urban areas in Brazil, China, India, Kenya, Italy, Oman, the UK and the USA where mothers received evidence-based health care, and the environmental and nutritional constraints on growth were minimal. From the total population, healthy, well-nourished women with problem-free pregnancies were enrolled to construct the standards.

The study is unique because it encompasses whole populations; involves large numbers of mothers and babies; and training, research methodology, equipment and quality control were standardized across all study sites. At birth, the length, weight and head circumference of almost 60,000 babies were measured. The growth of almost 4,500 of these babies was monitored from early pregnancy to birth using a range of ultrasound measurements (e.g. head and abdominal circumferences).

The new international fetal and newborn growth standards describe how babies in the womb should grow when they are provided with good health care and nutrition, and are living in a healthy environment. These are reliable tools to recognize inadequate growth that can be applied to the 120 million babies born every year in the world. In addition, more infants in developed regions may be diagnosed at birth as overweight and treated earlier to prevent chronic diseases later in life. Researchers now need to work with clinicians at regional, national and international levels to introduce the new tools into practice around the world.

These new standards for fetal growth and newborn size, and standardized methods for comparing length/height and head circumference for gestational age are the best ways to compare populations across the globe. Researchers hope their widespread use, in combination with the existing WHO Child Standards, will contribute to improved birth outcomes and reduced perinatal mortality and morbidity worldwide.

To access the full Lancet papers, visit this link.

Professor Zulfiqar Bhutta is Co-Director of the SickKids Centre for Global Child Health, one of the INTERGROWTH senior authors and Chair of the Study Steering Committee.