[Prevalence of iron deficiency in pregnant and premenopausal women in China: a nationwide epidemiological survey].

Objective: In order to better understand the iron status in pregnant and premenopausal nonpregnant women in China.

Methods: A nationwide epidemiological survey was undertaken in the year 2000 to investigate the prevalence rates (PR) of iron depletion (ID), iron deficiency anemia (IDA) and iron deficiency (ID + IDA). 3591 pregnant women and 3721 premenopausal women were selected by multi-stratification and random sampling from 26 cities and counties of 15 provinces. Hb was measured by cyanmethemoglobin assay, zinc protoporphyrin by hemo-fluorescein assay and serum ferritin by radioimmunoassay.

Results: The PR of ID and IDA were 42.6% and 19.1% in pregnant women, while 34.4% and 15.1% in premenopausal nonpregnant women respectively. There were statistical differences in the PR of IDA and ID + IDA in pregnant women between different trimesters (P < 0.01), with the highest in the third trimester (33.8%, 85.4%), followed by the second and the first trimesters. The prevalence rate of ID was also the highest during late pregnancy (51.6%), which was statistically different from that of early and mid-pregnancies (39.9% and 38.8% respectively), whereas there was no significant difference between the PR in early and mid-pregnancies. The PR of ID, IDA and ID + IDA in pregnant women were all significantly higher than that in premenopausal non-pregnant women (P < 0.01). The PR of ID in urban first-trimester pregnant women (41.9%) and premenopausal non-pregnant women (35.6%) were significantly higher than that in their rural counterparts (36.1% and 32.4% respectively P < 0.05). On the other hand, the PR of IDA in rural pregnant women in first-trimester (12.2%) and premenopausal non-pregnant women (17.4%) were significantly higher than that in their urban counterparts (8.2% and 13.8% respectively, P < 0.05). However, there was no significant difference between the PR of ID + IDA in urban pregnant women (62.0%), premenopausal nonpregnant women (49.4%) and then rural counterparts (61.1% and 49.7%).

Conclusions: IDA and latent iron deficiency are still quite common in Chinese pregnant and premenopausal nonpregnant women. Pregnant women in mid and late pregnancies are at risk for iron deficiency. Latent iron deficiency is more prevalent in urban pregnant and nonpregnant premenopausal women, but their rural counterparts were prone to the development of IDA.