Clinical usefulness of serum alpha-FP and free beta-hCG levels in midtrimester

Chung, Ji Youn; Kim, So Ra; Won, Hye Sung; Lee, Pil Ryang; Kim, Ahm

Abstract

OBJECTIVE
The aim of this study was to evaluate the detection rate of the chromosomal abnormalities by screening of maternal serum alpha-FP, free beta-hCG in midtrimester and to evaluate the association of elevated free beta-hCG with neonatal & pregnancy outcome.
METHODS
From October 1995 to December 1999, We studied 8,304 pregnant women who delivered in Asan Medical Center. We measured the levels of serum alpha-FP and free beta-hCG in the midtrimester. We reviewed high Down risk group, high NTD risk group and numerous cases of chromosomal abnormalities, retrospectively. To evaluate the association of elevated free beta-hCG with neonatal & pregnancy outcome, we reviewed birth weight, apgar score, gestational age at delivery, presence of PIH or fetal growth restriction.
RESULTS
Two hundred ninety eight (3.6%) women were screened as high Down risk pregnancy, 61 (0.7%) women were screened as high NTD risk pregnancy. In the high risk group of chromosomal abnormalities, there were 13 cases of various chromosomal abnormalites, including of six Down syndrome baby. In the low risk group, there were two (0.02%) Down syndrome baby and 8 cases of other chromosomal abnormality. By using maternal serum alpha-FP, free beta-hCG in mid-trimester, 68% of the detection rate of chromosomal abnormalites and 4.1% of false positive rate was reported. The detection rate of Down syndrome is 75% (6/8) and 3.5% of false positive rate, 0.02% of false negative rate were reported. In the aspect of pregnancy outcome, when the free beta-hCG more than 2.5MOM, there were more numerous preterm delivery (8.2% vs 3.8%), IUGR (4.6% vs 1.7%), lower 1 min apgar score than 7 (6.4% vs 2.7%).
CONCLUSION
Maternal serum alpha-FP, free beta-hCG is at least useful method as Double markers screening method for fetal chromosomal abnormalites and maybe elevated free beta-hCG level can be useful marker of poor pregnancy outcome such as PIH, low birth weight or preterm delivery.