Soluble FMS-like tyrosine kinase-1 (sFlt-1) and serum placental growth factor (PlGF) as biomarkers for ectopic pregnancy and missed abortion.

CONTEXT

Diagnosis of early pregnancy failure is hampered by the lack of reliable serological markers.

OBJECTIVE

We assessed whether a single serum measurement of placental growth factor (PlGF) and the soluble Flt-1 (sFlt-1) receptor of vascular endothelial growth factor at 6-8 wk gestation could differentiate failed pregnancies, whether ectopic pregnancies (EP) or missed abortions (MA), from healthy intrauterine pregnancies (IUP).

DESIGN AND SETTING

We conducted a prospective clinical study at a tertiary university hospital between January 2009 and February 2011.

PATIENTS

A total of 78 consecutive patients (38 EP, 40 MA) with failed early pregnancy and 50 IUP (control group) participated in the study.

INTERVENTION(S): Determination of serum PlGF and sFlt-1 has been carried out by ELISA. Gene expression of PlGF and Flt-1 in trophoblasts was performed by RT-PCR.

MAIN OUTCOME MEASURE(S): We investigated whether a single, combined serum measurement of the above markers could contribute to the differential diagnosis.

RESULTS

PlGF and sFlt-1 concentration was lower in both EP (mean, 14.60 ± 3.42/178.16 ± 76.03 pg/ml) and MA (mean, 16.25 ± 4.73/399.42 ± 337.54 pg/ml) compared to IUP (mean, 21.64 ± 5.68/1390.32 ± 655.37 pg/ml). sFlt-1 (P = 0.033) and sFlt-1/PlGF ratio (P = 0.029) but not PlGF had the ability to discriminate MA from EP. Compared to women with viable IUP, mRNA gene expression levels of PlGF and Flt-1 were considerably lower in women with MA and in women with EP.

CONCLUSIONS

Combined measurement of sFlt-1 and PlGF levels can differentiate normal from failed pregnancies, whereas sFlt-1 as well as sFlt-1/PlGF ratio can also discriminate EP from MA. PlGF and Flt-1 gene expression in trophoblasts from women with EP and MA appears impaired.