Weight percentile at birth. II. Prediction by endocrinological and sonographic measurements.

In a prospective study of 847 singleton pregnancies, the importance of various endocrine methods (serum estriol, HPL, SP1, beta-HCG, estradiol-17 beta, urinary estrogen excretion) and of two sonographic measurements (biparietal and thoracic diameter) for the diagnosis of growth retardation in the third trimester was studied. HPL and estriol determinations were best suited for the diagnosis of growth retardation. The thoracic diameter correlated most closely with the birthweight of the newborns. Sensitivity in relationship to growth retardation was between 17 and 35% for the HPL and estriol determinations as well as for both sonographic methods. Specificity was around 90% for these methods. The validity for all methods improved as the time of birth approached. Through the simultaneous measurement of one of the hormones and the thoracic diameter, an antepartal diagnosis of up to 50% of the hypo- and hypertrophic growth disorders was achieved. In the first two years of life a relationship between development and the HPL and estriol concentrations could be observed which was independent of the weight percentile at birth.