Fig. 2
From: Obstetric blood transfusion in placenta previa patients with prenatal anemia: a retrospective study
Correlation between prenatal hemoglobin levels and intraoperative blood transfusion-related parameters A Blood transfusion rate. B Massive blood transfusion rate. C Red blood cell transfusion units. D Fresh plasma transfused volume. The generalized additive model with a spline smoothing function (penalized spline method) was conducted to explore the nonlinear relationship between the prenatal hemoglobin level and intraoperative blood transfusion. The fitting curve is represented by solid dots, while the upper and lower 95% confidence intervals are represented by imaginary dots