目的：新生儿红细胞增多症发病因素复杂,以往多采用单因素分析法进行研究,该文以多因素分析法分析其独立危险因素,并分析因素间的交互作用,为该病防治提供依据。方法：采用病例对照研究对新生儿红细胞增多症27种危险因素进行调查,对单因素分析中有显著性意义的因素进行非条件logistic回归分析,并以加法模型理论分析因素间的交互作用。结果：单因素分析显示妊高征、窒息、宫内窘迫、小于胎龄儿、胎膜早破、早产、胎盘早剥、多胎妊娠、低出生体重等9个因素有显著性意义(P<0. 05);非条件logistic回归分析显示窒息(OR=7. 8255)、胎膜早破(OR=2. 7007)、妊高征(OR=2. 8313)、早产(OR=7. 7394)、低出生体重(OR=7. 4803)为红细胞增多症的独立危险因素;交互分析显示,低出生体重和小于胎龄儿、低出生体重与宫内窘迫、早产与小于胎龄儿之间存在正交互作用(交互指数大于1)。结论：该病的发生与多种独立危险因素有关,多个危险因素并存亦加大了该病发生的可能性,临床上应加强对相关危险因素的监测和处理。

OBJECTIVE: Neonatal polycythemia has a complicated etiology, for which monovariable analysis was generally used in the most previous studies.This paper investigated the independent risk factors for neonatal polycythemia by multivariable analysis and studied the interactions between the risk factors. METHODS: A case-control study was conducted to investigate 27 potential risk factors for neonatal polycythemia. These risk factors were significant in monovariable analyses and were selected for the non-conditional logistic regression analysis. The interactions of the risk factors were evaluated using an additive model. RESULTS: Monovariable analyses showed that pregnancy-induced hypertension syndrome, fetal asphyxia, fetal distress, small for gestational age, premature rupture of membranes, premature birth, placental abruption, multiple pregnancies and low birth weight were significant(P<0.05).Non-conditional logistic regression analysis indicated fetal asphyxia (OR=7.8255), premature rupture of membranes (OR= 2.7007),pregnancy-induced hypertension syndrome (OR=2.8313),premature birth (OR=7.7394) and low birth weight (OR=7.4803) as independent risk factors for neonatal polycythemia.The interaction analyses showed that there were positive interactions between low birth weight and small for gestational age, low birth weight and fetal distress,as well as premature birth and small for gestational age (synergy index>1). CONCLUSIONS: Risk for neonatal polycythemia is multifactorial. The coexistence of multiple risk factors may increase the incidence of this disorder. Clinically it is important to monitor and manage all potential risk factors.