Introduction In order to determine the prevalence of anaemia and to explore the associations between iron status and intake in the process of pregnancy, we compared the dietary and total intake of iron with the Dietary Reference Intakes (DRIs) for Japanese in a population of pregnant women in the suburbs.

Methods A total of 109 pregnant women participated in the survey and were measured for blood haemoglobin (Hb). For 42 (mean age ±SD: 30.2±4.5) clinically normal pregnant women (Hb concentration >11 g/dl) in the first trimester of pregnancy, we used the dietary record methods for two consecutive weekdays and a weekend day with a handy camera, to examine dietary intake of iron in the second trimester. Dietary intake analysis was performed using Healthy Maker Pro 501 software, Mushroom-soft. Statistical analysis was performed with SPSS for Windows, Version 11.5. Blood haemoglobin, haematocrit, serum iron, and ferritin were measured at the third trimester.

Results At the first trimester, anaemia was diagnosed in 48.6% of the subjects (Hb <11.0 g/dl). At the second trimester, iron intake was lower than the estimated average requirement of DRIs (16.5 mg/day) in 93% of the subjects. The level of latent iron deficiency anaemia (Ferritin <12 ng/dl) was 88.1% and the anaemia (Hb <11.0 g/dl) was 52.4% at the third trimester.

Conclusion The results of our study support that the iron deficiency anaemia is a physiological adaptation for prevention of thrombosis during pregnancy.