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Median levels of serum biomarkers of fetal Down syndrome detected during the first trimester among pregnant Thai women
Author(s) -
Luewan Suchaya,
Sirichotiyakul Supatra,
Yanase Yuri,
Traisrisilp Kuntharee,
Tongsong Theera
Publication year - 2012
Publication title -
international journal of gynecology and obstetrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.895
H-Index - 97
eISSN - 1879-3479
pISSN - 0020-7292
DOI - 10.1016/j.ijgo.2011.11.026
Subject(s) - medicine , pregnancy associated plasma protein a , gestational age , obstetrics , human chorionic gonadotropin , biomarker , pregnancy , fetus , gynecology , down syndrome , first trimester , endocrinology , hormone , biology , biochemistry , psychiatry , genetics
Objective To develop Thai‐specific medians of serum pregnancy‐associated plasma protein A (PAPP‐A) and free β‐human chorionic gonadotropin (hCG) levels during the first trimester of pregnancy and to compare these values to a Caucasian‐specific model for the detection of fetal Down syndrome. Methods Serum concentrations of PAPP‐A and free β‐hCG were measured during the first trimester in a group of 2339 Thai women undergoing normal singleton pregnancies. Results Thai reference ranges of PAPP‐A and free β‐hCG were established by gestational age (70–98 days). The equation of best fit for PAPP‐A was: predicted median PAPP‐A level = 28.767 – 0.781 × (gestational age in days) + 0.006 × (gestational age in days) 2 ; r = 0.986. The equation of best fit for free β‐hCG was: predicted median free β‐hCG level = 465.332 × 10 (–0.024 × gestational age in days) ; r = 0.881. Weight‐corrected models were also derived for each biomarker. The Thai‐specific reference ranges gave higher positive screening rates than the Caucasian‐specific model, even after weight correction (5.1% versus 4.0%). The Thai‐specific models were validated in an independent group of 302 pregnant women. Conclusion Ethnic group‐specific medians for PAPP‐A and free β‐hCG should be incorporated during first‐trimester screening for fetal Down syndrome.