Adverse Pregnancy Outcomes after a False-PositiveScreen for Down Syndrome using Triple Serum Markers

Roh, Cheong Rae; Chung, Jae Hyun

Abstract

OBJECT: To assess the relative risk of an adverse pregnancy outcome in women with a false-positive riskfor Down syndrome by prenatal screeen using triple markers(maternal serum alpha-fetoprotein[AFP], unconjugated estrio[uE3], and human chorionic gpna dotropin[hGC] levels) and age. METHODE: Case-Control study including sixity four women with false-positive screens for Down sydromeand a matched control group of 128 women whose screen indicated a risk for Down syndrome of less than1 :270. The risk for adverse pregnancy outcome was compared for the two groups,and the roles of maternal serum AFP, uE3, and hCG as predictors of adverse pregnancy outcome weredetermined. RESULT: Women with false-positive screen for Down syndrome were not significantly different from theirmatched controls in the incidence of preterm delivery (5% versus 2%), pretermpremature rupture of membrane(3% versus 0%), placental abruption(0% versus 1%),preeclampsia(3% versus 1%), small for gestational age newborns(5% versus 6%), and fetal demise after20 week's gestation(2% versus 0%). The occurrence of an adverse outcome in 7 of 64(11%) pregnancieswith a flase positive screen for Down syndrome was not different from that in 12 of 128(9%) matchedcontrol pregnancies.Only maternal age (odds ratio 1.19,95% cofidence interval 1.05~1.34, p < 0.005) was siginificantly associatedwith adverse outcome after controlling for the effects of maternal serum AFP, hCG and uF3.
CONCLUSION
Althought the sample on this study, women with a false-positive screen for Down syndromedo not seem to be at increased risk for a adverse pregnancy outcome when compared to those with a negativescreen result. Among maternal age, maternal serum AFP, hCG, and uE3level, only maternal age seemed tobe a predictorof an adverse pregnancy outcome.