Can maternal serum soluble fms-like tyrosine kinase-1 to placental growth factor levels at term anticipate adverse pregnancy outcomes?

Aim: To evaluate if maternal serum soluble fms-like tyrosine kinase-1(sFlt-1) to placental growth factor (PlGF) ratio levels at term can anticipate the following adverse pregnancy outcomes: small for gestational age neonates; operative delivery for suspected fetal welfare compromise; and neonatal compromise.

Methods: A retrospective analysis of a single hospital database containing antenatal soluble fms-like tyrosine kinase-1 to placental growth factor (sFlt-1/PlGF) ratio results together with associated demographic, clinical and investigative information. Subjects with antenatal sFlt-1/PlGF measurements taken ≥37 weeks' gestation were analyzed. sFlt-1/PlGF ratio cut-offs of <38, 38-110, 111-201 and >201 were tested against the following outcomes: birthweight ≤10th and ≤3rd centiles; operative delivery for suspected fetal welfare compromise; 5 min Apgar score; and neonatal admissions for extra care.

Results: Statistically significant associations were found between sFlt-1/PlGF ratios 111-201 and birthweights ≤10th centile (p < 0.01, odds ratio [OR] 3.04, 95% confidence interval [CI] 1.52-6.10), and between operative delivery for suspected fetal welfare compromise and sFlt-1/PlGF ratios 111-201 (p = 0.04, OR 2.21, 95% CI 1.03-4.75) and >201 (p = 0.01, OR 4.73, 95% CI 1.45-15.4).

Conclusions: This study indicates that maternal serum sFlt-1/PlGF ratios performed at term may subsequently help identify significantly small-for-gestational age fetuses and operative delivery for suspected fetal welfare compromise. Further prospective studies may confirm these findings and substantiate the clinical importance of sFlt-1/PlGF measurements in assisting the management of pregnancies at term.