The Iron Deficiency Disconnect: Missed Anemia in First Trimester and Its Impact on Obstetric Outcomes

Nur Aisyah ¹Zulkifli² Ain salihah³ Siti Mariam⁴

Abstract

Abstract:
Background: Early pregnancy anemia is underdiagnosed, often deferred to the second trimester, yet may silently contribute to adverse outcomes. This study evaluates prevalence, detection timing, and associations between first-trimester iron deficiency anemia (IDA) and pregnancy complications.
Methods: A multicenter prospective cohort study of 602 pregnant women in Malaysia was conducted between 2021 and 2024. Hemoglobin and ferritin were measured at first antenatal visit (<12 weeks). Women were followed for preeclampsia, preterm labor, and fetal growth restriction (FGR). Logistic regression was used to assess associations.
Results: IDA was diagnosed in 36.2% of women, but only 42.7% received early treatment. Undetected or untreated IDA was associated with higher rates of preeclampsia (15.1% vs. 6.4%, p = 0.002), preterm birth (12.3% vs. 5.2%, p = 0.01), and FGR (10.4% vs. 3.8%, p = 0.003). Ferritin <15 μg/L independently predicted complications (OR = 2.87, p = 0.005).
Conclusion: First-trimester IDA is prevalent and strongly linked to adverse pregnancy outcomes. Early ferritin screening should be incorporated into routine antenatal protocols to reduce preventable maternal-fetal morbidity.