Down Syndrome Screening Outcomes in Chaiyaphum Province

Abstract

Introduction: Down syndrome is a genetic disorder that causes developmental delays. The current policy of Thailand is for pregnant women of all age groups to be screened for Down syndrome at 14 - 18 weeks of gestation by quadruple test.

Objective: To study down syndrome screening outcomes and effectiveness of quadruple test in Chaiyaphum province.

Methods: This retrospective cohort study in medical record of pregnant women were underwent the quadruple test in Chaiyaphum province during 1 January to 31 December 2022.

Results: Total 3,702 pregnant women in Chaiyaphum province were performed quadruple test in 2022, mean age 27.3 years, standard deviation 6.4 years, 444 cases were at high risk of Down syndrome. 384 cases had amniocentesis. 71 cases refused amniocentesis. Amniocentesis results normal chromosomes in 375 cases (97.6%), Down syndrome in 3 cases (0.8%), Edwards syndrome in 1 case (0.3%), and other chromosomal abnormalities in 5 cases (1.3%). We found 2 infants who postpartum reported with Down syndrome was not undergo amniocentesis.

The effectiveness of the quadruple test in pregnant women of all age groups had a detection rate of 60 percent (95% CI, 14.7-94.7), specificity of 88.1 percent (95% CI, 87.0- 89.1), false-positive rate 11.9 percent (95% CI, 10.9-13.0), PPV 0.7 percent (95% CI, 0.3-1.4), NPV 99.9 percent (95% CI, 99.8-100.0), and accuracy 88.0 percent (95% CI, 86.9-89.1).

Conclusion and discussion: All of 3,702 pregnant women in Chaiyaphum province were underwent the quadruple test, reposted high risk for Down syndrome 444 cases, detection rate of 60 percent, false-positive rate 11.9 percent and accuracy 88.0 percent. This allows us to improve and develop the procedures for data and blood specimen collection to increase efficiency in the future.