Circulating soluble fms-like tyrosine kinase-1 and placental growth factor from 10 to 40 weeks' pregnancy in normotensive women.

Circulating soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are potential markers for preeclampsia. The objective was to construct and analyse the reference ranges of serum levels of sFlt-1 and PlGF throughout the course of pregnancy in low-risk Thai pregnant women.We enrolled 110 low-risk, Thai women singleton pregnancy from 10 to 40 gestational weeks. Serum concentrations of sFlt-1 and PlGF were measured with an automated assay. The reference ranges of serum levels of sFlt-1, PlGF and sFlt-1/PlGF ratio were constructed and assessed for possible correlations with gestational age, maternal factors [age, parity, tobacco use, artificial reproductive technologies (ARTS) and body mass index (BMI)], and pregnancy outcomes (gestational age at delivery, development of preeclampsia, neonatal birth weight and placental weight).None of the subjects developed preeclampsia. Serum sFlt-1 concentrations significantly elevated from 20 to 40 gestational weeks (P=0.003). Significant elevation and dropping of serum PlGF levels and sFlt-1/PlGF ratios were observed at 10 to 29 and 30 to 40 weeks of gestation, respectively (P 0.05). Effects from parity, smoking and ARTS were inconclusive.Robust change of serum PlGF levels suggests for its broader clinical application compared to sFlt-1. Prediction of preeclampsia using serum analytes may be gestational period specific.