Iron deficiency prevalence among pregnant women in Cambodia varies widely by trimester, inflammation adjustments, and across different ferritin thresholds.

Iron deficiency (ID) prevalence has been consistently reported as low among non-pregnant women in Cambodia, but less is known about iron status during pregnancy. Assessing iron status during pregnancy is critical, as deficiency can increase the risk of adverse pregnancy outcomes. We assessed anemia, ID, and inflammation prevalence in a cohort of pregnant women in Cambodia. Venous blood from 90 pregnant women (12-32 weeks' gestation) was collected before the start of a 2016 trial conducted in Prey Veng province. Gestational age was recorded on the same day as blood collection. Hemoglobin was measured on a hematology autoanalyzer, and ferritin, α-1 acid glycoprotein (AGP), and C-reactive protein (CRP) concentrations were measured with a sandwich-ELISA. Ferritin concentrations are presented as unadjusted and inflammation-adjusted (based on AGP and CRP concentrations). ANOVA and post-hoc pairwise t-tests were used to compare variables across trimesters of pregnancy. Mean±SD age of women was 26 ± 5 years. Most women (94%) reported consumption of iron and folic acid (IFA) tablets during pregnancy (mean±SD: 85 ± 19 tablets), and 72% received deworming treatment. Overall, 49% of women had anemia (hemoglobin <110 g/L for first and third trimesters; < 105 g/L for second trimester); with 43%, 34%, and 64% in the first, second and third trimester, respectively. ID prevalence (unadjusted ferritin <30 µg/L) ranged widely by trimester: 0%, 17% and 76% in the first, second and third trimester, as well as with use of a lower ferritin threshold (0-52%; < 15 µg/L), and whether ferritin was inflammation-adjusted (61% with and 43% without adjustment; < 30 µg/L). ID prevalence was high among women in third trimester, despite high IFA compliance. These findings underscore the need to consider the trimester of pregnancy in anemia and ID assessment. More research is needed to determine if trimester-specific thresholds for ferritin in pregnant populations are warranted and whether ferritin should be adjusted for inflammation in pregnancy.