The Use of Iron Supplements of Pregnant Women and Pregnancy Outcome

Cho, Ji Hyun; Ahn, Hong Seok; Bae, Hyun Sook

Abstract

It is known that Korean pregnant women take iron supplements at a higher than the recommended level. This study was designed to provide data on current iron intake levels both from food sources and supplement to better guide iron supplement use during pregnancy. We also explored associations of iron supplement intake levels with varioussociocultural factors and pregnancy outcomes. Dietary intakes of 510 pregnant women were assessed by a validated 102- item food frequency questionnaire, and information on types and amounts of nutritional supplement intakes were also attained. While dietary intake levels of most nutrients exceeded the KDRIs (Korea Dietary Reference Intakes: EAR: Estimated Average Requirements), folate fell short of the KDRIs. A total of 428 women (83.9%) reported to take iron supplement. The pregnant women were divided into the three groups (group I: Fe supplement intake < or = EAR, group II: EAR< Fe supplement intake < or = 3 times of EAR, group III: 3 times of EAR< Fe supplement intake). The mean dietary intake of iron was 24% of the total iron intake for pregnant women. Iron intake from food was not significantly different among I, II, and III. In case of iron intake from supplements, the most frequent dose (34.1%) was 90-100 mg/day, and the mean iron supplement intake was 362% of the EAR. The study findings showed that those with higher levels of iron supplements had better meal quality measured by NAR (Nutrient Adequacy Ratio) and INQ (Index of Nutrient Quality). In addition iron supplement intake levels were significantly related to age (20s: 66.5 +/- 38.6 mg/day, 30s: 77.3 +/- 47.8 mg/ day, p< 0.0116) and experience of childbirth (1st pregnancy: 70.9 +/- 41.2 mg/day, 2nd pregnancy: 64.5 +/- 39.5 mg/day, > or = 3rd pregnancy: 94.4 +/- 63.8 mg/day, p< 0.005). However, no significant difference was found between iron supplement intake levels and various pregnancy outcomes including birth weight, birth height, gestational age, weight gain during pregnancy, and jaundice. It is worrisome that iron intake by supplement use greatly exceeded the EAR, suggesting the need of appropriate guidelines for iron supplement intake during pregnancy. Thus iron overdose from supplements in pregnancy should be considered as a serious condition.