Study on anemia among premarital women in 6 counties from 1993 to 2003 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To describe the prevalence of anemia and yearly trends (1993-2003) among women who came to the hospitals or maternal and child health units for premarital examinations in 6 counties of Jiangsu and Zhejiang provinces.</p><p><b>METHODS</b>Data were obtained from the records of the premarital examinations in perinatal health care surveillance system that had been established since 1992 in these areas. We reviewed hemoglobin levels of those women who were enrolled in the perinatal health care surveillance system from 1993 to 2003. Anemia was defined according to the WHO (2001) criterion. We calculated the prevalence of anemia and analyzed the yearly trends based on the data of hemoglobin concentration.</p><p><b>RESULTS</b>In the period of 1993-2003, there were 82 995 anemia cases identified among 193,434 women with an overall anemia rate as 42.9%. The rates of anemia were high (65.5%) in 1993 but low (25.8%) in 2003. 99.7% of the anemic women whose hemoglobin concentration were between 80-119.9 g/L. Time trend analysis indicated a significant decline on anemia rate while monthly analysis showed that the prevalence rates were high (48.2%) in September and low in March (39.5%). The results also showed that the prevalence rates of anemia were relatively higher in farmers and workers in rural enterprises, and lower in Han ethnicity than minorities. The higher prevalence rates of anemia were presented among the women with less education, lower body mass index, or at older age.</p><p><b>CONCLUSION</b>For those premarital women in 6 counties of Jiangsu and Zhejiang provinces, the overall anemic rate presented a significant downward trend between 1993 and 2003 while the prevalence of anemia remained high, especially for the women with less education, lower body mass index or older ages.</p>

Association of pregnancy-induced hypertension with small-for-gestational-age babies / 中华流行病学杂志

Objective To examine the association between pregnancy-induced hypertension(PIH) and small-for-gestational-age babies(SGA)in a Chinese population.Methods Subjects were women who delivered a singleton baby(gestational weeks:equal to or greater than 28,and less than 42)in four cities or counties in Jiangsu and Zhejiang provinces,China,during the period of 1995-2000.A total number of 93 743 women were included.Incidence of SGA was calculated and compared between women with or without PIH and between groups with different severities of PIH.Multiple logistic regression was used to address the relationship between PIH and SGA while controlling for maternal age,occupation,education,parity,BMI,anemia,premature rupture of membranes and fetal sex.The association between PIH and SGA was also examined according to preterm or term delivery.Results The incidence of SGA in women with PIH(6.0%)was higher than women without(4.5%),and the incidence increased with severities of PIH.The adjusted relative risk rates(95%CI)of SGA in women with mild,moderate and severe PIH were 1.17(1.01-1.34),1.69(1.33-2.14),and 3.50(2.57-4.77),respectively,when confounders were controlled for.The risk ratios of SGA in women with PIH among women who delivered a preterm baby wete higher than those among women who delivered a term baby.Conclusion There seemed a statistical association between PIH and SGA,and women with PIH having higher incidence of SGA than those withont PIH.

Study on the third trimester hemoglobin concentrations and the risk of low birth weight and preterm delivery / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the association between third trimester hemoglobin (Hb) concentrations and the risk of low birth weight and preterm delivery in a Chinese population.</p><p><b>METHODS</b>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 Hb during the third trimester. Multiple logistic regression was used to address relationships between Hb levels and the risk of preterm delivery and low birth weight while controlling for potential confounding factors.</p><p><b>RESULTS</b>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 Hb 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 Hb value of 90-99 g/L. In addition, women with a high Hb concentration (Hb> 130 g/L) had 20% higher risk (95 % CI: 1..0-1.4) of preterm delivery and 50 % higher risk (95 % CI: 1.2-1.9) of low birth weight.</p><p><b>CONCLUSION</b>A U-shape relationship was found between Hb 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.</p>