Nuchal translucence incorporated into a one-stage multifactorial screening model for Down syndrome prediction at second-trimester pregnancy.
The aim of this study was to achieve one-stage screening for trisomy 21 using a combination of nuchal translucency (NuT) measurement and maternal serum alpha-fetoprotein (AFP) and free beta-human chorionic gonadotrophin (hCG) biochemistry levels in the second trimester among a high-risk study population. From January 1998 to June 2001, 45 cases of trisomy 21 were prenatally found and confirmed in the hospital-based cytogenetic diagnosis laboratory. A total of 867 normal singleton pregnancies were enrolled as controls from the antenatal care clinics in the hospital. All study and control subjects between 13 weeks and 18 weeks of gestation with a mean age of 15.2 +/- 1.3 weeks underwent one-stage nuchal translucence measurements and maternal serum biochemical screening for Down syndrome. The final logistic model contained beta-hCG (multiples of the gestational median or MoM), maternal age (matA), nuchal translucence (NuT MoM) and AFP (MoM) as covariates. Also, the estimated coefficients of the regression were highly significant. This model provided the estimated probability of Down syndrome as follows: Pr (Down syndrome) = exp (Z)/ [1 + exp (Z)], where Z = -11.18 + 0.64 x (beta-hCG MoM) + 0.25 x matA + 1.32 x NuT MoM -2.23 x AFP MoM. The logistic regression with estimated coefficients was installed in a Palm digital assistant (PDA) equipped with Excel (Microsoft). The risk probability of Down syndrome could be readily calculated after inputting data for all four predictor variables.
Hung
Jeng-Hsiu
JH
Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan. jhhung@vghtpe.gov.tw
Fu
Chong-Yau
CY
Yuan
Chiou-Chung
CC
Chen
Cheng-Li
CL
Yang
Man-Li
ML
Shu
Li-Ping
LP
Wu
Chih-Chieh
CC
D000328:Adult; D015415:Biomarkers / Q000097:blood; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008423:Maternal Age; D009333:Neck / Q000000981:diagnostic imaging* / Q000196:embryology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood; D011262:Pregnancy Trimester, Second; D018566:Pregnancy, High-Risk; D016216:Ultrasonography, Prenatal / Q000379:methods*; D000509:alpha-Fetoproteins / Q000032:analysis
D015415:Biomarkers; D000509:alpha-Fetoproteins