Babies Born to Healthy Mothers Similar in Size

Researchers found that children born to healthy mothers across the world were similar in size at birth.

Researchers at the Oxford University analyzed the international study INTERGROWTH-21^st that involved 60,000 pregnancies from eight urban areas and found that babies born to well-educated and well-nourished mothers worldwide were of similar size.  

The eight urban areas included Brazil, China, Italy, India, Kenya, Oman, UK and the U.S.

Studies in the past have highlighted that race and ethnicity play a role in differences in sizes of new born babies. This study finding suggests that rather than race and ethnicity, it is the educational, health and nutritional status of the mother including care provided during pregnancy, that matters.

"Currently we are not all equal at birth. But we can be," said the lead author, Professor Jose Villar of the Nuffield Department of Obstetrics & Gynaecology, University of Oxford. "We can create a similar start for all by making sure mothers are well educated and nourished, by treating infection and by providing adequate antenatal care."

Ultrasound scans were conducted right from early pregnancy to delivery to measure the bone growth of the baby in the womb. They also measured the length and head circumference of the babies after birth.

Small babies have an increased risk of diabetes, hypertension and cardiovascular diseases in adulthood.  The only challenge in improving pregnancy outcome in fetal growth is that various clinics use various growth charts and there is no international standard for measuring the newborn.

"This is very confusing for doctors and mothers and makes no biological sense. How can a fetus or a newborn be judged small in one clinic or hospital and treated accordingly, only for the mother to go to another city or country, and be told that her baby is growing normally," said Professor Stephen Kennedy, University of Oxford, one of the senior authors of the paper.

The aim of this study is to create international standards clearly describing the optimal growth of the baby in the womb as well as a newborn.

"The INTERGROWTH-21st results fit perfectly with the existing WHO standards for infants. The mean length at birth of the newborns in the INTERGROWTH-21st study was 49.4 ± 1.9 cm, compared with 49.5 ±1.9 cm in the WHO infant study," researchers say.

The finding will be published in The Lancet Diabetes & Endocrinology.