Associations Between Soluble fms‐Like Tyrosine Kinase‐1 and Placental Growth Factor and Disease Severity Among Women With Preterm Eclampsia and Preeclampsia

BACKGROUND: The angiogenic factors soluble fms‐like tyrosine kinase‐1 (sFlt‐1) and placental growth factor (PlGF) are postulated to be pathogenic disease drivers of preeclampsia. If true, then circulating levels should become more deranged with increasing disease severity. METHODS AND RESULTS: We investigated the association between circulating sFlt‐1 and PlGF levels and severe adverse maternal outcomes among 348 women with preeclampsia. Compared with 125 women with preeclampsia without severe features, 25 women with preeclampsia and any of hemolysis, elevated liver enzymes, low platelet count syndrome, disseminated intravascular coagulation, or severe renal involvement had sFlt‐1 levels that were 2.63‐fold higher (95% CI, 1.81–3.82), sFlt‐1/PlGF levels that were 10.07‐fold higher (95% CI, 5.36–18.91) and PlGF levels that were 74% lower (adjusted fold change, 0.26 [95% CI, 0.18–0.39]). Compared with 125 women with preeclampsia without severe features, 37 with eclampsia had sFlt‐1 levels that were 2‐fold higher (2.02 [95% CI, 1.32–3.09]), sFlt‐1/PIGF levels that were 4.71‐fold higher (95% CI, 2.30–9.66) and PIGF levels that were 63% lower (0.43‐fold change [95% CI, 0.27–0.68]). Compared with those without severe features, preeclampsia with severe hypertension (n=146) was also associated with altered angiogenic levels (sFlt‐1, 1.71‐fold change [95% CI, 1.39–2.11]; sFlt/PlGF, 2.91 [95% CI, 2.04–4.15]; PlGF, 0.59 [95%CI 0.47–0.74]). We also found that sFlt‐1 and PlGF levels were altered by the number of maternal complications experienced. CONCLUSIONS: Further angiogenic imbalance among women with preeclampsia is likely a pathogenic disease driver responsible for the life‐threatening maternal complications.