A customized standard to assess fetal growth in a US population.
OBJECTIVE
The objective of the study was to assess the factors that affect fetal growth and birthweight, and to derive coefficients for a customized growth chart applicable in an American population.


METHODS
This was a prospective cohort study of 35,235 pregnancies. Coefficients for physiological and pathological variables were derived by backward multiple regression.


RESULTS
The expected birthweight at 40.0 weeks for a standard-size primiparous mother of European origin in an uncomplicated pregnancy was 3453.4 g, very similar to the standardized birthweight observed in other populations. Physiological coefficients were derived for maternal height, weight, parity, ethnic origin, and sex of the baby. Smoking, history of preterm delivery, and hypertensive diseases in the current pregnancy all had negative effects on birthweight, whereas babies of diabetic mothers weighed more. Low as well as high body mass index was associated with birthweight deficit at term.


CONCLUSIONS
Coefficients that allow determination of the customized growth potential, individually adjusted and excluding known pathological factors, have been derived. Babies of obese mothers have an increased risk of not reaching their fetal growth potential.
Gardosi
Jason
J
West Midlands Perinatal Institute, Birmingham, England, UK. jason.gardosi@pi.nhs.uk
Francis
Andre
A
D001724:Birth Weight / Q000502:physiology; D015992:Body Mass Index; D005006:Ethnicity / Q000706:statistics & numerical data; D047109:Fetal Development; D006801:Humans; D009035:Mothers; D011446:Prospective Studies; D012016:Reference Values; D012044:Regression Analysis; D014481:United States