正常妊娠妇女阴道分娩后血红蛋白及铁蛋白水平的研究

Study of hemoglobin and ferritin levels in normal pregnant women after vaginal delivery

目的:了解正常妊娠妇女阴道分娩后血液稀释状态下血红蛋白(hemoglobin,Hb)、铁蛋白(serum ferritin,SF)水平及其生理性变化规律,探讨产褥期贫血筛查时机及阈值。方法:选取正常足月妊娠经阴道分娩产妇103例,于分娩前、分娩后24h,48h,72h,7d及42d行Hb、红细胞计数(red blood cell,RBC)、红细胞压积(hematocrit,HCT)检测,于分娩前,分娩后24h,7d,42d行SF检测。根据分娩前SF水平分为正常组与铁缺乏组(SF<20μg/L认为铁缺乏),采用t检验、两因素重复测量方差分析、单因素重复测量方差分析对数据进行分析。结果:分组与时间因素交互作用对Hb,RBC的影响差异无统计学意义(P>0.05)。两者随时间变化趋势一致,产后3d内出现明显下降,然后显著上升至产后7d,产后7~42d缓慢增长。分组与时间因素交互作用对HCT,SF的影响差异有统计学意义(P<0.05)。两组SF产后呈持续上升趋势,产后24h^7d较为显著,但铁缺乏组增长趋势较正常组缓慢。两组HCT水平在产前无明显差异(P>0.05),产后不同时间铁缺乏组HCT均低于正常组,差异有统计学意义(P<0.05)。Hb水平在产后24h为最低点,产后7d时显著上升接近产前水平,差异无统计学意义(P>0.05)。结论:由于血液稀释,产后3d内Hb明显下降,可导致生理性贫血,产后7d检测Hb较为准确,建议联合SF筛查评估产妇是否缺铁。

Objective:To understand the hemoglobin,ferritin levels and physiological changes of normal pregnant women after vaginal delivery,and to discussing the timing and threshold screening for postpartum anemia.Methods:The study population included women who delivered vaginally after 37 weeks’ gestation (n=103).They were tested for hemoglobin,erythrocyte (RBC) and hematocrit (HCT) before the delivery and at 24 h,48 h,72 h,7 d and 42 d after the delivery,tested for ferritin before the delivery and at 24 h,7 d and 42 d after the delivery.According to the ferritin level before the delivery,it was divided into a normal group and an iron deficiency group (ferritin <20 μg/L was considered to be iron deficiency).We used two factors repeated measurement ANOVA,t-test,and single-factor repeated measurement ANOVA to analyze the data.Results:The interaction between group and time had no statistically significant effect on Hb and RBC (P>0.05).Both of them showed the same trend over time:a significant decrease in postpartum 3 d followed by a significant increase to postpartum 7 d,and a slow increase from postpartum 7 d to postpartum 42 d.Interaction between group and time factors had statistical significance on HCT and SF (P<0.05).The postpartum SF showed a continuous upward trend,which was significant from 24 h to 7 d after the delivery.The growth trend of iron deficiency group was slower than that of the normal group.There was no significant difference in the HCT levels between the two groups before deliver (P>0.05),and the HCT levels in the iron deficiency group at different postpartum time were lower than those in the normal group,and the difference was statistically significant (P<0.05).The Hb level reached its lowest point at 24 h after the delivery,and rose significantly close to the prenatal level at 7 d after the delivery,with no statistically significant difference (P>0.05).Conclusion:Due to blood dilution,hemoglobin decreased significantly within 3 d after the delivery,leading to physiological anemia.It is more accurate to screen hemoglobin at 7 d after the delivery.It is suggested that joint ferritin screening assess maternal iron deficiency.