title: Normal range of intracranial translucency in healthy Turkish pregnancies and its association with first trimester maternal serum biochemistry and ductus venosus pulsatility index. .
abstract: OBJECTIVE
  To measure the intracranial translucency (IT) by establishing reference ranges in uncomplicated singleton Turkish pregnancies and to evaluate the association of IT with maternal serum biochemistry, gestational week, crown-rump length (CRL) measurement, nuchal translucency (NT) and ductus venosus Doppler velocimetry.
  
  
  METHODS
  190 uncomplicated singleton pregnancies were included in the study. IT, NT and CRL measurements between 11-14 gestational weeks were obtained with mid-sagittal plane. Two independent measurements were taken and averaged to obtain the final measurement used in the calculations. Statistical analysis was performed with SPSS for Windows 20.0 software package. Correlation analysis was used to determine the association between IT and NT pregnancy-associated plasma protein-A (PAPP-A), free β-human chorionic gonadotropin (β-hCG) and CRL length. A p-value of <0.05 was considered statistically significant.
  
  
  RESULTS
  The assessment rate of IT was 167/190 (87.89%). The mean CRL length, gestational week, NT and IT measurements were 63.63±10.05 mm, 12.28±0.75 weeks, 1.23±0.43 mm (range: 0.20-2.68) and 2.29±0.49 mm (range: 0.18-3.80), respectively There was no significant correlation between IT and maternal serum PAPP-A MoM (r=-0.34, p=0.698) or maternal serum free β-hCG MoM (r=-0.79, p=0.363), respectively. There was weak but statistically significant correlation between IT with with maternal weight (r=0.172, p=0.047), CRL length (r =0.301, p<0.001), gestational week (r=0.286, p=0.001) and NT measurement (r=0.224, p=0.007), respectively. There was no significant association between IT with ductus venosus Doppler pulsatility index (r=0.108, p=0.213).
  
  
  CONCLUSIONS
  IT can be easily measured while scanning for NT. This study shows normal range values in healthy Turkish pregnancies. Consistent with recent data, our results show positive correlation with gestational week and CRL length. Maternal serum biochemistry does not have any effect on IT. Besides, our study highlights that IT is correlated with NT and adds newly to the literature that there is no correlation of IT with ductus venosus pulsatility index.
authors.forename: Burcu
authors.initials: B
authors.lastname: Artunc-Ulkumen
authors.forename: Halil Gursoy
authors.initials: HG
authors.lastname: Pala
authors.forename: Yildiz
authors.initials: Y
authors.lastname: Uyar
authors.forename: Yesim
authors.initials: Y
authors.lastname: Bulbul-Baytur
authors.forename: Faik Mumtaz
authors.initials: FM
authors.lastname: Koyuncu
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D018568:Crown-Rump Length; D005260:Female; D006801:Humans; D016011:Normal Distribution; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood*; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis*; D012016:Reference Values; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A