Pregnancy Outcome in Women with False-Positive Screen for Down Syndrome Using Second Trimester Maternal Serum Triple Markers

Kim, S K; Cho, J S; Kim, S Y; Choi, H M; Lim, J C; Kim, I K; Yang, Y H; Song, C H; Kim, J U

Abstract

OBJECTIVE
Our purpose was to study the pregnancy outcome in women whose triple marker screening [maternal serum AFP, unconjugated estriol, hCG, and maternal age] indicating an increased risk for Down syndrome [more than 1 : 270] was not confirmed by amniocentesis [false-positive result].
METHODS
Between January 1995 and August 1997, 1,070 pregnant women undergoing second trimester triple marker screening for Down syndrome who gave birth at our institution were evaluated. The pregnancy outcomes of 56 women with false-positive screens for Down syndrome were compared with 1,014 screen negative controls. The pregnancy outcomes were obtained from hospital delivery records. Pregnancies with fetal chromosomal and structural anomalies were excluded from the study
RESULTS
An adverse pregnancy outcome occurred in 6 of 56 women [10.7%] with false-positive screens for Down syndrome, compared with 80 of 1,014[7.9%] in the screen negative controls [p=0.291]. The study group was not significantly different from the control group in the incidence of preterm delivery [5.4% vs. 3.5%], preeclampsia [0% vs. 1.8%], abruptio placentae [0% vs. 0.2%], intrauterine growth retardation [5.4% vs. 2.0%], and fetal death [0% vs. 0.5%]. Among six women with adverse pregnancy outcome in the study group, low uE3 level[< or = 0.75 MoM] and high hCG level [> or = 2.0 MoM] were more frequently associated with adverse pregnancy outcome than low AFP level[< or = 0.4 MoM].
CONCLUSION
Women with false-positive screens for Down syndrome do not appear to be associated with adverse pregnancy outcomes.