Maternal anemia across pregnancy in a multi-ethnic tertiary maternity center in a Singaporean population: prevalence, risk factors, and pregnancy outcomes.

Abstract

Maternal anemia affects 36 to 50% among pregnant women worldwide. Despite its prevalence and potential harm, contemporary data across different trimesters in multi-ethnic Asian populations remain limited. This retrospective study investigates the prevalence, risk factors and outcomes associated with maternal anemia among 1,005 mothers at a tertiary hospital in Singapore across the first (T1), second (T2), and third (T3) trimesters. We conducted a retrospective cohort study of 1,005 pregnant women receiving antenatal care at Singapore General Hospital between 2016 and 2017. Anemia was defined using World Health Organization trimester-specific hemoglobin thresholds. Associations between demographic and clinical factors and maternal anemia were assessed using univariate and multivariable logistic regression adjusted for ethnicity and body mass index (BMI). Maternal and neonatal outcomes were summarized descriptively. Maternal anemia was identified in 664 women (66.2%) at any point during pregnancy. Prevalence was the highest in T1 (36.9%) and T2 (37.0%), and the lowest in T3 (23.4%). After adjustment, advanced maternal age (≥35 years) was independently associated with T1 anemia (adjusted odds ratio [aOR] 1.40, 95% CI 1.00-1.96). Ethnicity was the strongest predictor across pregnancy, with significantly higher odds among Indian (T1 aOR 3.40; T2 aOR 3.50; T3 aOR 14.1) and Malay women (T1 aOR 2.60; T2 aOR 2.70; T3 aOR 7.80) compared with Chinese women. Maternal and neonatal complications were uncommon overall (2.2 and 0.7%, respectively). Maternal anemia was highly prevalent in this multi-ethnic tertiary obstetric cohort, particularly in early pregnancy and among Indian and Malay women. These findings support early risk stratification and sustained antenatal surveillance, alongside targeted nutritional counseling and education for higher-risk groups, to reduce preventable maternal and neonatal morbidity.