Graduation Date

Spring 5-10-2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Programs

Medical Sciences Interdepartmental Area

First Advisor

Dr. Ann L Anderson-Berry

Second Advisor

Dr. Teri J Mauch

Third Advisor

Dr. Corrine K Hanson

Fourth Advisor

Dr. Sathish Kumar Natarajan

MeSH Headings

Retinol, Provitamin A Carotenoids, Vitamin A, Fetal Development, Infant Development, Kidney Development, Kidney Size, Carotenoids, Alpha-Carotene, Beta-Carotene, Beta-Cryptoxanthin, Fetal Kidney, Fetal Kidney Ultrasound, Umbilical Cord Blood, Plasma, Retinol Deficiency, Pregnancy, Maternal Nutritional Physiological Phenomena, Maternal Blood, Pregnancy Complications, Nephrology, Nephron Count, Chronic Kidney Disease, Longitudinal Studies, Ultrasound, Pregnancy Trimester, Gestational Age, Infant Kidney, Infant Ultrasound, Nutrient-Related Health Effects

Abstract

Vitamin A plays a critical role in fetal organ development. Studies suggest that maternal vitamin A deficiency affects fetal nephron numbers, potentially leading to smaller kidney sizes and an increased risk of chronic kidney disease later in life. However, human studies exploring maternal vitamin A's impact on fetal kidney development lack longitudinal data and within-cohort comparisons. Furthermore, the influence of provitamin A carotenoids (α-carotene, β-carotene, β-cryptoxanthin) on kidney size remains unexplored. This dissertation addresses these gaps by analyzing relationships between maternal and cord plasma retinol and provitamin A carotenoid concentrations with fetal and infant kidney sizes. Our prospective cohort study enrolled 120 pregnant women in Nebraska before their anatomy scans (18–20 weeks). Retinol and provitamin A concentrations were measured at 24–28 weeks of gestation and at delivery in maternal circulation and umbilical cord. Ultrasounds were used to assess fetal kidney length, volume, and parenchymal thickness at 18–20 weeks and infant kidney measurements within 48–72 hours of birth. Kidney size differences were examined across retinol adequate, insufficient, and deficient groups. Most participants had adequate plasma retinol concentrations. Maternal retinol levels at 24–28 gestational weeks or at delivery and cord retinol levels were not associated with fetal or infant kidney size. However, maternal α and b-carotene at 24–28 gestational weeks were significantly and positively associated with fetal kidney lengths. Interestingly, cord a-carotene levels were significantly positively associated with infant kidney lengths. Lastly, the change in maternal plasma retinol from gestation to delivery was not associated with the change in fetal kidney size from gestation to birth. On the other hand, the changes in maternal a-carotene and b-carotene were significantly positively associated with changes in fetal kidney lengths. This study concludes that adequate maternal retinol concentrations are not associated with fetal kidney development, but fetal kidney development may be influenced by maternal provitamin A carotenoids during pregnancy. These findings emphasize the significance of maintaining adequate carotenoid levels during pregnancy to support fetal kidney development. Further studies are needed to determine the mechanism by which provitamin A carotenoids influence kidney size.

Comments

2025 Copyright, the authors

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Available for download on Tuesday, July 29, 2025

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