ELEVATED 2ND-TRIMESTER MATERNAL SERUM HCG - A MARKER OF INADEQUATE ANGIOGENESIS

Objective: To measure angiogenin, a potent inducer of neovascularizati on and interleukin-6, as an indicator of acute inflammation, in second -trimester amniotic fluid of patients with elevated maternal serum hCG . Methods: In this case-control study, 20 patients with elevated mater nal serum hCG (at least 2.0 multiples of median) at triple screen were matched 2:1 with controls on the basis of year of amniocentesis, pari ty, and race. Inclusion criteria were 1) singleton gestation, 2) no ev idence of anomalies, and 3) genetic amniocentesis. Amniotic fluid was immunoassayed for angiogenin and interleukin-6. The immunoassay sensit ivity for angiogenin was 0.026 ng/mL, interassay coefficient of variat ion 4.6%, and intra-assay coefficient of variation 2.9%. For interleuk in-6, the immunoassay sensitivity was 2.37 pg/mL, interassay coefficie nt of variation 2.7%, and intra-assay coefficient of variation 1.9%. A ngiogenin and interleukin-6 values were normalized by using natural lo g transformation for statistical analysis. Statistical analysis includ ed analysis of variance and stepwise regression, with P < .05 signific ant. Results: After correcting (by multivariate regression) for gestat ional age at sampling and nulliparity, amniotic fluid angiogenin level s were significantly lower in the study subjects than in controls (26% +/- 11% lower, P = .004), whereas the interleukin-6 levels did not ch ange significantly (34% +/- 40% lower, P = .3). Conclusion: Amniotic f luid angiogenin levels are significantly lower in patients with elevat ed maternal serum hCG at triple screen, suggesting inadequate angiogen esis, but interleukin-6 values do not differ significantly. (C) 1998 b y The American College of Obstetricians and Gynecologists.