Related Experiment Video
Updated: Jun 8, 2026

FISH for Pre-implantation Genetic Diagnosis
Published on: February 24, 2011
Second-trimester maternal serum screening for fetal Down syndrome: As a screening test for hemoglobin Bart's disease:
Chanane Wanapirak1, Wirawit Piyamomgkol1, Supatra Sirichotiyakul1
1Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Purpose:
The purpose of this study is to determine the effectiveness of second-trimester maternal serum screening for Down syndrome as a screening test for fetal hemoglobin (Hb) Bart's disease among an unselected population.
Methods:
A secondary analysis of a large prospective database (20 254 pregnancies) was conducted to compare the levels of maternal serum screening, alpha-fetoprotein (AFP), free beta-human chorionic gonadotropin, and unconjugated estriol between pregnancies with Hb Bart's disease and unaffected pregnancies.
Results:
The median AFP levels were much higher among affected fetuses (1.96 vs 1.12 multiple of the median; P < .001), yielding a sensitivity of 81.6% and specificity of 86.4%. Thus, AFP measurement is effective in predicting fetal Hb Bart's disease among an unselected population when using a cutoff value of 1.5 multiple of the median. The serum free beta-human chorionic gonadotropin levels were slightly, but significantly, higher in the affected pregnancies, while the serum unconjugated estriol levels were minimally, but significantly, lower among the affected pregnancies.
Conclusion:
Second-trimester maternal serum AFP levels were significantly elevated in cases of fetal Hb Bart's disease. Pregnancies with unexplained elevated serum AFP levels in areas of high prevalence of Hb Bart's disease should always undergo a detailed ultrasound examination to detect any early signs of fetal anemia before development of hydrops fetalis.
Related Concept Videos
Meiosis vs. Mitosis
Before the start of mitosis and meiosis I, the cell synthesizes DNA, resulting in two homologous copies of each chromosome. DNA synthesis is...
Genome-wide Association Studies-GWAS
GWAS does not require the identification of the target gene involved in...
Teratogenicity
Diabetes Mellitus: Type 2 and Gestational
Pathophysiology of Diabetes
Type 1 diabetes is characterized by autoimmune-mediated destruction of pancreatic β cells, with environmental factors potentially triggering this process in genetically susceptible individuals. Despite many not having a family history, certain genes increase susceptibility, suggesting a...

