The impact of inherited thrombophilia on first trimester combined aneuploidy screening test parameters

Abstract

Objective: To determine whether inherited thrombophilia affects components of first trimester combined aneuploidy screening test.Method: A case–control study was performed between January 1st and December 31st 2011, at a tertiary referral hospital. Singleton pregnancies with inherited thrombophilia that underwent first trimester (11–13+6 week) combined aneuploidy screening test were included in the study. Pregnancy associated plasma protein-A (PAPP-A), free beta-human chorionic gonadotropin (fbHCG) and fetal nuchal translucency (NT) were compared between the study group and controls.Results: Within the study period, 15 881 women with singleton pregnancies had a combined first trimester aneuploidy screening test at our institution. Among these, 207 women met the inclusion criteria. A control group that comprised 625 women with similar gestational age was generated, using a 1:3 ratio. PAPP-A levels were significantly higher, whereas fbHCG levels and fetal NT measurements were lower in women with inherited thrombophilia (p < 0.001).Conclusion: Our study suggested that PAPP-A, free b-HCG and NT MoM levels display alterations in women with inherited thrombophilia. Future trials are needed to assess the need for readjustment of risk in these patients.