Prepregnancy Obesity Is Not Associated with Iron Utilization during the Third Trimester

Area of Science:

• Obstetrics and Gynecology
• Nutritional Science
• Maternal-Fetal Medicine

Background:

• Maternal iron is vital for red blood cell expansion, placental and fetal growth, and fetal brain development.
• Obesity in pregnancy may impair iron status due to inflammation-induced hepcidin, reducing iron bioavailability.

Purpose of the Study:

• To investigate the impact of prepregnancy obesity on maternal iron utilization during the third trimester of pregnancy.

Main Methods:

• Stable isotope 57Fe was used to measure iron utilization in the third trimester.
• Iron status, hepcidin, inflammation markers, erythropoietin, dietary iron, and gestational weight gain were assessed.
• Statistical analyses included Student t tests and Pearson correlations.

Main Results:

• No significant difference in third-trimester iron utilization was observed between prepregnancy obese and nonobese women.
• Prepregnancy obese women exhibited higher C-reactive protein levels and greater total body iron corrected for inflammation.
• Anemia prevalence was similar between groups, but obese women had less depleted iron stores, suggesting sequestration.

Conclusions:

• Prepregnancy obesity does not alter third-trimester maternal iron utilization.
• Obesity may lead to iron sequestration, despite higher anemia rates.
• Further research is needed to understand the implications for fetal iron bioavailability.