Obstetric blood transfusion in placenta previa patients with prenatal anemia: a retrospective study

Table 4 Association between the level of maternal preoperative hemoglobin and maternal outcomes based on two-piecewise linear regression analysis

	Effect size adjusted β/OR	95% CI	P	P for the log-likelihood ratio test
Blood transfusion rate				< 0.001
Hemoglobin < 12 g/dL	0.37	(0.30, 0.46)	< 0.0001
Hemoglobin ≥ 12 g/dL	1.03	(0.66, 1.60)	0.9093
Massive blood transfusion rate^a				0.033
Hemoglobin < 12 g/dL	0.57	(0.43, 0.75)	< 0.0001
Hemoglobin ≥ 12 g/dL	0.00	(0.00, Inf)	0.9847
Red blood cell transfusion units				< 0.001
Hemoglobin < 12 g/dL	-1.18	(-1.41, -0.95)	< 0.0001
Hemoglobin ≥ 12 g/dL	0.04	(-0.56, 0.63)	0.9062
Fresh plasma transfusion volume				0.039
Hemoglobin < 12 g/dL	-81.46	(-103.49, -59.43)	< 0.0001
Hemoglobin ≥ 12 g/dL	-9.33	(-66.61, 47.96)	0.7498

A two-piecewise linear regression model was used to examine the threshold effect of the prenatal hemoglobin level on intraoperative blood transfusion using a smoothing function. Likelihood ratio tests were conducted to compare the one-line linear regression model with a two-piecewise linear model
Adjusted for region, occupation, number of caesarean sections, uterine anomalies (bicornuate uterus, adenomyosis, uterine fibroids or prior uterine surgery), hemorrhage during pregnancy, emergency surgery, placental location, placenta previa types, and placenta accrete spectrum
Abbreviations: OR odds ratio, CI confidence interval
^aMassive blood transfusion is defined as the transfusion of 10 units of packed red blood cells within a 24-h period

ISSN: 1471-2393