ELEVATED 2ND-TRIMESTER MATERNAL SERUM HCG ALONE OR IN COMBINATION WITH ELEVATED ALPHA-FETOPROTEIN

Objective: To evaluate the clinical significance of a second-trimester elevated maternal serum hCG in women carrying singleton, chromosomall y normal fetuses. Methods: The results of second-trimester maternal se rum screening (alpha-fetoprotein [MSAFP], hCG, and unconjugated estrio l) for 25,438 women were reviewed, and those with hCG values exceeding 3.0 multiples of the median (MoM) were identified. A control populati on was selected only on the basis of samples accessioned by the labora tory at the same time as the study group. Follow-up information was co llected from physicians' offices for both groups. Incidence of fetal o r neonatal loss (spontaneous abortion, fetal death, and neonatal death combined), preterm birth (before 37 weeks' gestation), small for gest ational age, and preeclampsia were compared. Results: Three hundred tw enty-two women (1.3%) had hCG levels exceeding 3.0 MoM. In addition to chromosomal abnormalities and fetal death at the time of testing, thi s group showed a significantly higher incidence of fetal or neonatal d eath, preterm birth, low birth weight, and preeclampsia than did contr ols. For patients with elevated second-trimester hCG, many of the pret erm deliveries occurred before 34 weeks' gestation. Logistic regressio n analysis indicated that hCG, MSAFP, and race were significant indepe ndent factors in predicting risk for adverse outcomes. Conclusions: Si milar to elevated AFP, elevated hCG is associated with poor pregnancy outcome. By combining the results of the two tests, it may be possible to improve substantially the identification of patients at very high risk for adverse outcomes.