title: Effect of increased body mass index on first-trimester ultrasound examination for aneuploidy risk assessment.
abstract: OBJECTIVE
  To estimate whether body mass index (BMI) affects the evaluation of nuchal translucency or the nasal bone during first-trimester ultrasound examination for aneuploidy risk assessment.
  
  
  METHODS
  Six hundred ninety-four women with singleton gestations undergoing first-trimester aneuploidy risk-assessment ultrasound examinations were identified. Weight categories were defined as normal (body mass index [BMI] less than 25), overweight (25-29.9), and obese (at or above 30). chi, chi for trend, Student t test, one-way analysis of variance, and Pearson correlation were used for statistical analysis where appropriate to estimate the effect of BMI on first-trimester ultrasound examination. P<.05 was considered statistically significant.
  
  
  RESULTS
  Increasing BMI was significantly associated with an inadequate nasal-bone assessment (3% compared with 12.7%, P<.001), increased ultrasound examination time (15.23+/-8.09 minutes compared with 17.01+/-7.97 minutes, P=.028), and an increased need to perform a transvaginal ultrasound examination (23% compared with 41.8%, P<.001). Prior abdominal surgery was not significantly associated with nasal-bone assessment inadequacy (7.8% compared with 4.4%, P=.125), the need to perform transvaginal ultrasound examination (33.6% compared with 28.6%, P=.279), or longer examination time (16.22+/-8.6 minutes compared with 15.92+/-7.8 minutes, P=.704).
  
  
  CONCLUSIONS
  In singleton pregnancies, increased BMI is not associated with suboptimal visualization of nuchal translucency, but it is associated with a longer time to perform the first-trimester ultrasound examination for aneuploidy risk assessment, increased need for transvaginal ultrasound examination for nuchal-translucency visualization, and a lower likelihood of obtaining an adequate nasal-bone image. Previous abdominal surgery did not affect the ability to visualize the nasal bone.
  
  
  METHODS
  II.
authors.affiliation: From the Mount Sinai School of Medicine, New York, New York; and Valley Hospital Maternal-Fetal Medicine, Paramus, New Jersey.
authors.forename: Manisha
authors.initials: M
authors.lastname: Gandhi
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Fox
authors.forename: Karen
authors.initials: K
authors.lastname: Russo-Stieglitz
authors.forename: Mary Ellen
authors.initials: ME
authors.lastname: Hanley
authors.forename: Gail
authors.initials: G
authors.lastname: Matthews
authors.forename: Andrei
authors.initials: A
authors.lastname: Rebarber
mesh_terms: D000328:Adult; D000782:Aneuploidy; D015992:Body Mass Index; D005260:Female; D006801:Humans; D009666:Nose / Q000000981:diagnostic imaging; D048208:Nuchal Translucency Measurement; D009765:Obesity / Q000000981:diagnostic imaging*; D050177:Overweight / Q000000981:diagnostic imaging; D011247:Pregnancy; D013997:Time Factors