High prevalence and associated factors of red blood cell folate deficiency among first-trimester pregnant women in a neural tube defect high-risk Region of Tigray, Northern Ethiopia

Background The Tigray region of northern Ethiopia has one of the highest reported prevalences of neural tube defects (NTDs) globally. Red blood cell (RBC) folate is the gold-standard biomarker for assessing long-term folate status and predicting the risk of folate-sensitive NTDs. This study assessed RBC folate concentrations and dietary diversity among first-trimester pregnant women in Tigray. Methods A facility-based cross-sectional study was conducted from March to April 2025 in five randomly selected public hospitals in Tigray, Ethiopia. A total of 400 first-trimester pregnant women (≤13 weeks of gestation) were selected using systematic random sampling. Sociodemographic, anthropometric, obstetric, and dietary data were collected using interviewer-administered questionnaires and a 24-hour dietary recall based on the Food and Agriculture Organization Minimum Dietary Diversity for Women (MDD-W) tool. RBC folate concentrations were measured using electrochemiluminescence immunoassay. Descriptive statistics summarized the data, and an exploratory L 2 -penalized (Ridge) logistic regression model was fitted because of the rarity of folate sufficiency. Results The mean RBC folate concentration was 221.6 ± 68.6 ng/mL, with a median of 204.9 ng/mL. Overall, 98.8% of participants (395/400; 95% CI: 97.1%–99.6%) had RBC folate concentrations below the WHO-recommended threshold of 400 ng/mL for optimal NTD prevention. Additionally, 79.5% (318/400) of participants did not achieve the minimum dietary diversity threshold (<5 food groups). Among women who achieved minimum dietary diversity, 97.6% (80/82) remained folate deficient. In the exploratory Ridge regression, achieving minimum dietary diversity was positively associated with folate sufficiency (AOR = 1.82), whereas increasing maternal age was inversely associated (AOR = 0.67). Conclusions This study demonstrates that maternal RBC folate deficiency was present in almost all first-trimester pregnant women in Tigray, highlighting a substantial public health concern in a region with a high burden of neural tube defects. The finding that clinical deficiency crosses all demographic and dietary tiers indicates that individual-level dietary modification and sporadic supplementation are insufficient to protect maternal reserves. Safely addressing this structural micronutrient emergency and reducing the high burden of NTDs requires an immediate transition toward mandatory, large-scale food fortification of staple grains in Northern Ethiopia.