First and Second Trimester Serum sFlt-1/PlGF Ratio and Subsequent Preeclampsia: A Systematic Review

Objective: Angiogenic biomarkers may be predictive of preeclampsia before clinical symptoms. The objective of this review was to determine the relationship between first and second trimester soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio and preeclampsia. Methods: A search algorithm using appropriate medical subject headings was developed. PubMed, EMBASE, and Cochrane were searched for publications from inception to July 4, 2017. Observational studies, including prospective and retrospective cohorts, that measured serum sFlt-1/PlGF ratio at <= 24 weeks' gestation were included. Study characteristics, study design, timing of blood samples, and outcome data were systematically extracted. Study cohorts were grouped into women with low-risk and high-risk factors for preeclampsia. Results: Fifteen studies were included for analysis, including 11 779 pregnancies. In studies of women with low-risk features, four subgroups from seven studies demonstrated higher sFlt-1/PlGF ratios in women who developed preeclampsia versus those who did not. In studies of women with high-risk features, six subgroups from nine studies demonstrated a higher sFlt-1/PlGF ratio in women who later developed preeclampsia. Elevated sFlt1/PlGF ratios were especially seen in women who had early-onset or severe preeclampsia. Conclusion: The serum sFlt-1/PlGF ratio measured at <= 24 weeks' gestation may be elevated in select women who later develop preeclampsia, but inconsistently so. Copyright (c) 2018 The Society of Obstetricians and Gynaecologists of Canada/La Societe des obstetriciens et gynecologues du Canada. Published by Elsevier Inc. All rights reserved.