INTRODUCTION: Extreme levels of either PAPP-A or free β-hCG may be a serious clinical concern. A multicentre study was carried out to determine the frequency and clinical consequences of high (minimum 2,0 MoM) maternal (PAPP)-A and free beta hCG.

METHODS: A total number of 8591 patients with singleton pregnancies between 11 + 0-13 + 6 weeks of gestation were enrolled. A total number of 612 cases with first trimester serum level of PAPP-A corresponding to ≥ 2,0 MoM and/or free β-hCG to ≥ 2,0 MoM were included in the statistical analysis. All serum samples were analysed with Roche (Cobas) or Kryptor (Brahms) devices. A retrospective analysis of perinatal outcomes was conducted.

RESULTS: Values of PAPP-A ≥ 2,0 MoM and free β-hCG < 2.0 MoM were detected in 48,5% of patients (n = 297), free β-hCG ≥ 2,0 MoM and PAPP-A concentration < 2,0 MoM in 38,1% of patients (n = 233) and both PAPP-A and free β-hCG ≥ 2,0 multiple of median in 13,4% of patients (n = 82). The highest PAPP-A and free β-hCG concentrations were 19,2 MoM and 16,3 MoM respectively. Patients with both PAPP-A and free β-hCG above 2,0 MoM had a slightly higher (but statistically not significant) prevalence of history of low birthweight (8,3%).

DISCUSSION: Pregnancy outcomes in women with normal ultrasound findings and high PAPP-A /free β-hCG concentration are good. Higher prevalence of pregnancy complications was not detected in either extremely high PAPP-A and free β-hCG concentration groups. In cases of normal ultrasound and isolated high (even extreme) biochemical markers levels the counselling should be comforting.