title: Growth of the fetal orbit and lens in normal pregnancies.
abstract: OBJECTIVE
  To construct nomograms of the size of the fetal orbit and lens during gestation.
  
  
  METHODS
  The study group included 349 normal pregnant women at 14-36 weeks' gestation.
  
  
  METHODS
  Routine biometric measurements were obtained in all the participants; these included biparietal diameter, head and abdominal circumferences, measurements of the long bones and the diameters of the fetal orbit and lens. The orbital and lens circumference measurements were also related to gestational ages.
  
  
  RESULTS
  A linear growth function was observed between gestational age (GA) and orbital diameter (r = 0.94; p < 0.00001; y = -0.66 + 0.5 x GA), orbital circumference (r = 0.94; p < 0.00001; y = -2.1 + 1.5 x GA) and orbital area (r = 0.94; p < 0.00001; y = -98.1 + 8.3 x GA). Significant correlation was also found between femoral length (FL) and orbital diameter (r = 0.95; p < 0.00001; y = 3.3 + 1.9 x FL), orbital circumference (r = 0.95; p < 0.00001; y = 10.3 + 5.9 x FL) and orbital area (r = 0.93; p < 0.00001; y = -28.2 + 32.2 x FL). A linear growth function was observed between orbital circumference and biparietal diameter (r = 0.94; p < 0.00001) and head circumference (r = 0.95; p < 0.00001). A linear growth function was also observed between gestational age and the diameter of the lens (r = 0.89; p < 0.00001; y = 0.88 + 1.4 x GA) the circumference of the lens (r = 0.89; p < 0.00001; y = 2.78 + 0.4 x GA) and the area of the lens (r = 0.89; p < 0.00001; y = -7.95 + 1.0 x GA). The correlation was found between the ratios of the diameters, circumferences and areas of the lens and the orbit.
  
  
  CONCLUSIONS
  These results provide normative data of the growth of the fetal orbit and lens and may aid future studies relating to fetal eye anomalies.
authors.affiliation: Department of Obstetrics and Gynecology, Rambam Medical Center, Haifa, Israel.
authors.forename: I
authors.initials: I
authors.lastname: Goldstein
authors.forename: A
authors.initials: A
authors.lastname: Tamir
authors.forename: E Z
authors.initials: EZ
authors.lastname: Zimmer
authors.forename: J
authors.initials: J
authors.lastname: Itskovitz-Eldor
mesh_terms: D000328:Adult; D002508:Cephalometry; D016001:Confidence Intervals; D005314:Embryonic and Fetal Development / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007908:Lens, Crystalline / Q000196:embryology* / Q000254:growth & development; D016014:Linear Models; D008875:Middle Aged; D009915:Orbit / Q000196:embryology* / Q000254:growth & development; D011247:Pregnancy; D012016:Reference Values; D016216:Ultrasonography, Prenatal