In this retrospective case–control analysis, we found out that sFlt-1/PlGF, PlGF, PlGF% and sFlt-1 are statistically associated with low birth weight and/or small-for-gestational age withp < 0.05 in pregnancy complicated or uncomplicated with preeclampsia, and sFlt-1/PlGF showed a more significant difference withp < 0.01, meaning sFlt-1/PlGF is a better indicator in distinguishing pregnancy that will deliver low birth weight and/or small-for-gestational age neonates. The gene discussed is PGF; the disease is preeclampsia.