妊娠晚期血红蛋白浓度与早产和低出生体重关系的研究

Study on the third trimester hemoglobin concentrations and the risk of low birth weight and preterm delivery

目的分析妊娠晚期血红蛋白（Hb）浓度与早产和低出生体重之间的关系。方法研究对象为江苏和浙江省4个县（市）在1995—2000年间分娩的102489名妇女。按妊娠晚期Hb浓度分四组比较各组早产和低出生体重的发生率；采用logistic回归模型控制年龄、职业、文化程度、孕次、产检次数和妊高征等因素后，估计Hb与早产和低出生体重的关联程度。结果妊娠晚期贫血患病率为48．2％，以轻度和中度贫血为主。轻、中度贫血不增加早产和低出生体重的风险。当Hb为90～99g／L时，早产和低出生体重的发生率最低；当Hb升高或降低时，早产和低出生体重的风险均呈增加趋势。Hb为70～119g／L时，早产和低出生体重的风险变化不大，但重度贫血和高血红蛋白则显著增加早产和低出生体重的风险：Hb〈70g／L组早产和低出生体重的OR（95%CI）分别为1．8（1.0～3.3）和4．0（2．1～7．5）；Hb≥130g/L组的早产和低出生体重的OR（95％CI）为1．2（1．0～1．4）和1.5（1．2～1．9）。结论妊娠晚期Hb水平与早产和低出生体重的风险之间均呈“U”形趋势，妊娠晚期重度贫血以及高血红蛋白均是早产和低出生体重的危险因素。

Objective To investigate the association between third trimester hemoglobin （Hb） concentrations and the risk of low birth weight and preterm delivery in a Chinese population. Methods Subjects were women who delivered in four cities/counties in Jiangsu and Zhejiang provinces, China, during the period of 1995 - 2000. Incidence of low birth weight and preterm delivery was calculated and compared among groups of women with different levels of Fib during the third trimester. Multiple logistic regression was used to address relationships between Fib levels and the risk of preterm delivery and low birth weight while controlling for potential confounding factors. Results The overall prevalence of anemia during third trimester of pregnancy was 48.2%, mainly consisting of mild and moderate anemia. Mild and moderate anemia did not increase the risk of preterm delivery and low birth weight statistically. The lowest incidence of preterm delivery and low birth weight was found among pregnant women with Fib levels at 90-99 g/L. The risk for preterm delivery and low birth weight increased with either increasing or decreasing hemoglobin concentrations. However, there was no remarkable elevation of the risk when Hb was in the range of 70- 119 g/L. Women with severe anemia （Hb〈70 g/L） had 80% higher risk （95% CI：1.0-3.3） of preterm delivery and a 4.0-fold higher risk （95 % CI：2.1-7.5） of low birth weight compared with women with an Fib value of 90-99 g/L. In addition, women with a high Hb concentration （Hb≥ 130 g/L） had 20 % higher risk （95 96 CI ： 1.0-1.4） of preterm delivery and 50 % higher risk （95 96 CI ： 1.2-1.9） of low birth weight. Conclusion A U-shape relationship was found between Fib concentration and the risk of preterm delivery and low birth weight. Severe anemia and high hemoglobin concentration were both associated with increased risk of preterm deliveries and low birth weight.