Investigating the Relationship Between Micronutrient Deficiency, Oxidative Stress, and Foetal Growth Restriction in Pregnant Women in the North Central Zone: A Mechanistic Cohort Study

Foetal growth restriction (FGR) in Nigerian pregnancies is multifactorial, with micronutrient deficiency and oxidative stress potentially acting as mediating mechanisms, yet a mechanistic cohort study characterising these relationships in the North Central zone has not been conducted. This dissertation investigates the mechanistic relationship between micronutrient deficiency, oxidative stress biomarkers, and FGR in pregnant women across Kogi, Benue, and Plateau States, North Central Nigeria. A prospective cohort of 250 singleton pregnancies was enrolled at 16 to 20 weeks gestation. Serum zinc, selenium, vitamin D, and vitamin A concentrations were measured at enrolment and at 32 weeks. Oxidative stress was quantified by malondialdehyde (MDA), superoxide dismutase (SOD), and 8-hydroxy-2-deoxyguanosine (8-OHdG) at both time points. Foetal growth was monitored by serial biometric ultrasound, with FGR defined as estimated foetal weight below the 10th centile at 34 weeks. FGR prevalence was 16.8 percent. Zinc deficiency at 20 weeks (OR 3.1), selenium deficiency (OR 2.7), and vitamin D insufficiency (OR 2.4) were independently associated with FGR. Mediation analysis showed that 44 percent of the zinc deficiency-FGR relationship was mediated by elevated MDA and 8-OHdG, implicating oxidative stress as a mechanistic pathway. Selenium deficiency showed a stronger direct effect. The dissertation introduces the Micronutrient-Oxidative Stress-FGR Pathway (MOSFP) model specific to North Central Nigerian population nutritional and environmental exposures. Keywords: foetal growth restriction, micronutrient deficiency, oxidative stress, North Central Nigeria, zinc