การศึกษาความชุกของหญิงตั้งครรภ์ที่มีความเสี่ยงสูงต่อการตั้งครรภ์กลุ่มอาการดาวน์ จากการตรวจคัดกรองด้วย Quadruple test ของโรงพยาบาลราชพิพัฒน์

Thammarat Prayoonsook

Authors

Thammarat Prayoonsook Department of Medical Technology, Ratchaphiphat Hospital, Bangkok, Thailand

Keywords:

Down syndrome, Prevalence, Quadruple test, Pregnant women

Abstract

Down syndrome is a chromosomal disorder caused by the presence of an extra copy of chromosome 21. Early detection of this abnormality during pregnancy allows for appropriate prenatal care and management. In Thailand, the National Health Security Office (NHSO) has established a universal benefit policy that provides screening for Down syndrome in all pregnant Thai women, regardless of age or healthcare scheme by using the quadruple test, with nationwide implementation. This study is a retrospective analysis conducted at Ratchaphiphat Hospital, including 438 pregnant women who underwent screening using the quadruple test. The objectives were to determine the prevalence of pregnant women at high risk for Down syndrome and to evaluate the screening performance of the quadruple test. The prevalence of high-risk pregnancies for Down syndrome was found to be 14.38% (95% CI: 11.09-17.67%). The quadruple test demonstrated a specificity of 85.62% (95% CI: 82.33-88.91%), a negative predictive value (NPV) of 100% (95% CI: 99.00-100%), and a false-positive rate of 14.38% (95% CI: 11.09-17.67%). In conclusion, pregnant women of all age groups may be at risk of carrying a fetus with Down syndrome. The quadruple test provide high reliability for negative screening results, indicating a very low likelihood of Down syndrome in the fetus. However, for cases with positive screening results, confirmatory prenatal diagnostic testing is essential.

References

The committee for the development of laboratory practice guidelines for the diagnosis of Down syndrome in pregnant women, Guidelines for laboratory testing of Down syndrome in pregnant women. 2019: 2 (in Thai)

Centers for Disease Control and Prevention (CDC). Living with Down syndrome [Internet]. Atlanta (GA): CDC; 2024 [cited 2025 Nov 17]. Available from: https://www.cdc.gov/birth-defects/living-with-down-syndrome/index.html.

Down syndrome statistics – births and population in Australia [Internet]. 2024 [cited 2025 Oct 22]. Available from: https://www.downsyndrome.org.au/about-down-syndrome/statistics.

National Down Syndrome Society. About Down Syndrome [Internet]. New York: NDSS; 2024 [cited 2025 Jun 9]. Available from: https://ndss.org/about?utm=.

Weijerman ME, de Winter JP. Clinical practice: the care of children with Down syndrome Eur J Pediatr 2010; 169: 1445-52.

Steinbock B. Life before birth: the moral and legal status of embryos and fetuses. 2nd ed. Oxford: Oxford University Press; 2011: 222.

The subcommittee on professional standards of the Royal Thai College of Obstetricians and Gynaecologists. Term Year 2013-2015. The Royal Thai College of Obstetricians and Gynaecologists clinical practice guideline, Down syndrome screening in pregnant women. 2015: 43-50. (in Thai)

Lee DE, Kim H, Park J, Yun T, Park DY, Kim M, Ryu HM. Clinical validation of non-invasive prenatal testing for fetal common aneuploidies in 1,055 Korean pregnant women: a single center experience. J Korean Med Sci 2019; 34: e172. doi:10.3346/jkms.2019.34.e172.

Al-Zahrani AM, Alghamdi SA, Alasmari MH, Alahmari MM, Alnakhli NM, et al. Validity of chromosomal aneuploidies testing during pregnancy: A comparison of karyotype, interphase-FISH and QF-PCR techniques. J Genet Mol Biol 2019; 3: 1-6.

Webb R. Size calculation for proportion [Internet]. California: UC Davis Library, California State University; 2023 [cited 2025 May 26]. Available from: https://stats.libretexts.org/Bookshelves/

Introductory_Statistics/Mostly_Harmless_Statistics_%28Webb%29/07%3A_Confidence_Intervals_for_One_Population/7.03%3A_Sample_Size_Calculation_for_a_Proportion?utm.

Department of Health, Ministry of Public Health. Guidelines for Down syndrome screening in pregnant women using the Quadruple Test for healthcare providers. Nonthaburi: Department of Health, Ministry of Public Health; 2021. p. 4-8. (in Thai).

Wongkrajang P, Charoenkwan P, Limpaiboon T, Denduangboripant J, Khorana J, Charoenkwan K. Performance of the second-trimester quadruple test for Down syndrome screening in a large Thai population. PLoS One 2023; 18: e0288301. doi:10.1371/journal.pone.0288301.

Siriwipat A. Outcome of Down syndrome screening using quadruple test at Phatthalung Hospital. Region 11 Med J 2022; 37: 34. (in Thai)

Chaibunruang S, Chewasateanchai M, Phanich P, Polying S, Kongwong T. Effectiveness of quadruple test for Down syndrome screening pregnant women at Regional Health Promotion Center 7 Khon Kaen. Regional Health Promotion Center 7 Khon Kaen J 2024; 3: 228-31. (in Thai)

Luo W, Cheng J, Wang C, Yang H, Zhang Y, Xu R, et al. Evaluation of second-trimester maternal serum quadruple screening for detecting fetal chromosomal abnormalities in 30,830 pregnancies. Sci Rep 2020; 10: 159. doi:10.1038/s41598-019-57046-z.