The value of repeated evaluation after initial failed nuchal translucency measurement.
OBJECTIVE
The purpose of this study was to assess the value of reattempting the nuchal translucency (NT) measurement after an initial failure.


METHODS
Women undergoing NT measurements by NT-certified sonographers within a combined screening program over an 18-month period were categorized as "desiring" screening (all women), "eligible" (live fetus with crown-rump length of 45-84 mm), and "defaulters" (failed to keep a visit after a failed NT measurement attempt). If the NT measurement was unobtainable, patients with live fetuses and a crown-rump length of less than 84 mm were offered reexamination.


RESULTS
Nuchal translucency measurement success rates at the initial visit for those desiring (n = 837) and eligible (n = 767) were 73.3% and 80.0%, respectively. Composite NT measurement success rates for up to 3 visits were significantly greater than for only 1 visit for those desiring screening (84.8%; P < .0001), eligible for screening (86.6%; P = .0004), and not defaulting on follow-up (97.0%; P < .0001). The screen-positive rates were similar for 1 and up to 3 visits (10.4% and 11.0%). One additional (16.6%) aneuploidy was detected through a second visit.


CONCLUSIONS
Reattempting NT measurements significantly increases the overall NT measurement success rate and detects additional aneuploidies at constant screen-positive and invasive prenatal diagnosis rates.
Wax
Joseph R
JR
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Maine Medical Center, Portland, Maine 04102 USA. waxj@mmc.org
Pinette
Michael G
MG
Cartin
Angelina
A
Blackstone
Jacquelyn
J
D025063:Chromosome Disorders / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D048208:Nuchal Translucency Measurement / Q000379:methods*; D011247:Pregnancy; D011785:Quality Assurance, Health Care / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity