A case-control study to evaluate whether a single serum measurement of angiopoietin-1 (ANG-1) and angiopoietin-2 (ANG-2) at 6-8 weeks gestation can differentiate failed pregnancies, whether ectopic pregnancies (EP) or missed abortions (MA), from healthy intrauterine pregnancies (IUP).Serum and tissue mRNA determination of ANG-1 and ANG-2 levels by ELISA and RTPCR, from 60 (30 EP and 30 MA) patients with failed early pregnancy and 33 IUPs.ANG-1 and ANG-2 concentrations and their ratio are lower in EP (median, 689 and 302 pg/ml, respectively) and MA cases (median, 810 and 402 pg/ml, respectively) compared to IUP (median, 963 and 1477 pg/ml, respectively) (p<0.05, for all). Unlike ANG-2, serum ANG-1 discriminates an EP from a MA (p=0.011). Trophoblastic ANG-1 mRNA expression levels are lower in EP compared to MA and IUP (p<0.05), while ANG-2 mRNA is higher in EP and MA than in IUP (p<0.05).A single measurement of serum ANG-1 and ANG-2 at 6-8 weeks of gestation designate the outcome of a pregnancy, as their levels are significantly decreased in failed than normal pregnancies. Serum ANG-1 showed potential to discriminate MA from EP.