Orbital diameter, inner and outer orbital distance. A growth model of fetal orbital measurements

Abstract

Aim of this study was to establish a growth model for the intrauterine growth of the following fetal parameters: orbital diameter, interorbital and biocular diameters. Data were measured in a prospective cross-sectional study with real-time ultrasound. The study group consisted of 1090 healthy fetuses between 12 and 41 weeks gestation. For curve standardisation a growth model for all parameters was used. Using this growth model growth profiles (5., 50., and 95. percentiles) were established. All orbital parameters showed a nonlinear growth. Since ocular and orbital malformations (anophthalmia, microphthalmia, hypo- and hypertelorism) are often principal signs of generalised syndromes, orbital biometry is helpful for a detailed prenatal investigation of the fetal face. This is demonstrated in 2 cases with an orbital malformation (orbital hypoplasia, hypotelorism).