Unexplained elevated maternal serum β-HCG concentration and adverse pregnancy outcome.

Objective To investigate the association between unexplained elevated maternal serum β-Human chorionic gonadotrophin (HCG) in the second trimester of pregnancy and adverse pregnancy outcome. Methods In a case-controlled study of 3463 women who opted for second-trimester serum screening for Down syndrome, 142 were found to have a serum β-HCG of ≥3.5 multiples of the median (MoM), 56 of whom had a serum β-HCG of ≥5.0 MoM. These women were compared with a control group of women with serum β-HCG within the 95% confidence interval around the median. Results In the elevated β-HCG group (≥5 MoM) significantly more babies required admission to the special care baby unit ( p = 0.02) and were small for gestational age (SGA) ( p = 0.03). The mean birth weight was also significantly lower in the group with elevated β-HCG. Women with a serum β-HCG of ≥5, ≥6, ≥7 or ≥8 MoM were associated with SGA babies in 40, 44, 64 and 86% respectively. All babies born to the six women with β-HCG of 8.75-24.1 MoM were SGA. Conclusion Increased surveillance is necessary in pregnancies where the maternal serum β-HCG in the second trimester is inexplicably elevated to ≥5 MoM. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]