Iron Absorption and Transfer to the Fetus During Pregnancy in Normal Weight and Overweight/Obese Women and the Effects on Infants Iron Status
- Conditions
- ObesityPregnancyOverweight
- Interventions
- Other: Stable iron isotope 57 (57Fe) labeled iron solutionOther: Stable iron isotope 58 (58Fe) labeled iron solution
- Registration Number
- NCT02747316
- Lead Sponsor
- Swiss Federal Institute of Technology
- Brief Summary
Overweight and obesity causes low-grade systemic inflammation, which sharply increases risk for iron deficiency. Studies in our laboratory have shown that this is mainly the result of reduced dietary iron absorption because of increased hepcidin concentrations. During pregnancy, women have a large increase in iron needs because of the expansion of maternal blood volume and fetal needs. Iron deficiency anemia in infancy can impair cognitive development. Whether maternal adiposity impairs absorption and transfer of iron to the fetus, and thereby increases risk of iron deficiency in the mother and the infant is unclear.
- Detailed Description
In obese subjects, hepcidin concentrations are increased and iron absorption is believed to be reduced, leading to iron deficiency over time. How all this will influence iron supply of the fetus in obese pregnancy has not been well investigated to date. Even if maternal and fetal iron uptakes are regulated separately, it is unclear to what extent maternal subclinical inflammation might influence this process. A small study by Dao et al. indicated that maternal-fetal iron transfer was impaired in obese pregnant women, possibly due to hepcidin up-regulation. In this study, both maternal BMI as well as hepcidin were negatively correlated with cord blood iron status. Maternal hepcidin and c-reactive protein were significantly higher and cord blood iron was significantly lower in the obese compared to the normal weight. Hepcidin was shown to have an effect on iron transfer across the placenta in the study by Young et al.: the transfer was increased in women with undetectable hepcidin at delivery compared to those with higher levels. As of now, clear associations between maternal BMI or maternal hepcidin concentration and fetal iron status were not shown.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Female
- Target Recruitment
- 83
- Pregnant women with either normal pre-pregnancy BMI (BMI 18.5 - 24.9kg/kg2) or with overweight or obesity (BMI > 27.5kg/m2) before pregnancy (assessed based on data reported by the women at their first visit at the hospital)
- 18 to 45 years old
- singleton pregnancy
- week of pregnancy 14±3
- underlying malabsorption disease
- chronic illness, which influences iron absorption
- inflammatory status other than obesity
- medical problems known to affect iron homeostasis
- smoking during pregnancy
- no regular use of medication, which influences iron absorption
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Isotopically labeled test meal week of pregnancy 20 Stable iron isotope 57 (57Fe) labeled iron solution - Isotopically labeled test meal week of pregnancy 30 Stable iron isotope 58 (58Fe) labeled iron solution -
- Primary Outcome Measures
Name Time Method infants iron status over the first six months of life infants iron status
iron transfer from the mother to the fetus in cord blood/infant delivery To determine the amount of iron transferred from the mother to the fetus
Fractional iron absorption week 30 of pregnancy The fractional iron absorption from the second test meal will be calculated based on the shift of the iron isotopic ratios in the collected blood samples 14 days after administration of the isotopically labeled meal.
- Secondary Outcome Measures
Name Time Method Assessment of children's iron needs within their first 2 years of life using an isotope dilution technique Follow-up blood samples at 3, 6, 12, 18, 24 months after birth Assessment of children's iron needs within their first 2 years of life
Assessment of recovery of mother's iron Status after pregnancy using an isotope dilution technique Follow-up blood samples at 3, 6, 12, 18, 24 months after delivery Assessment of recovery of mother's iron Status after pregnancy
Change in hemoglobin weeks of pregnancy 12, 18, 20, 28, 30, 36; 3 and 6 months after delivery Change in hemoglobin
Change in c-reactive protein weeks of pregnancy 12, 18, 20, 28, 30, 36; 3 and 6 months after delivery Change in c-reactive protein
Change in riboflavin weeks of pregnancy 12, 18, 20, 28, 30, 36; 3 and 6 months after delivery Change in riboflavin
Change in transferrin receptor weeks of pregnancy 12, 18, 20, 28, 30, 36; 3 and 6 months after delivery Change in transferrin receptor
Change in plasma ferritin weeks of pregnancy 12, 18, 20, 28, 30, 36; 3 and 6 months after delivery Change in plasma ferritin
Change in Hepcidin weeks of pregnancy 12, 18, 20, 28, 30, 36; 3 and 6 months after delivery Change in Hepcidin
infants iron status over the first 24 months of life infants iron status
Change in interleukin-6 weeks of pregnancy 12, 18, 20, 28, 30, 36; 3 and 6 months after delivery Change in interleukin-6
Chage in alpha-1-acid glycoprotein weeks of pregnancy 12, 18, 20, 28, 30, 36; 3 and 6 months after delivery Chage in alpha-1-acid glycoprotein
Change in retinol binding protein weeks of pregnancy 12, 18, 20, 28, 30, 36; 3 and 6 months after delivery Change in retinol binding protein
Trial Locations
- Locations (1)
Human Nutrition Laboratory ETH Zurich
🇨🇭Zurich, Switzerland