Pregnancy 5 Flashcards
What is epigenetics, and how does it relate to the Developmental Origins of Health and Disease (DOHaD) theory?
Epigenetics refers to modifications in gene expression without altering DNA sequences. According to the DOHaD theory, early life nutrition and environment influence lifelong health by altering epigenetic patterns.
How does DNA methylation impact fetal development?
DNA methylation regulates gene expression and has long-term effects on health. After fertilization, DNA is demethylated to near 0%, then remethylated to establish fetal epigenetic patterns.
What are the consequences of inadequate folate and choline intake during pregnancy on DNA methylation?
Insufficient folate and choline can lead to improper methylation patterns, affecting fetal gene expression and increasing susceptibility to chronic diseases later in life.
Why are iron requirements higher during pregnancy?
Increased iron is needed for:
Fetal growth.
Higher maternal hemoglobin production due to increased blood volume.
Blood supply to the uterus, placenta, and fetal tissues.
What are the 3 risks of inadequate iron intake during pregnancy?
Low birth weight, preterm birth, stillbirth, or infant death.
Iron deficiency anemia, leading to pallor, exhaustion, and increased risk of complications during and after birth.
Reduced oxygen delivery to tissues, impairing fetal development.
How does iron deficiency affect fetal brain and metabolic development?
Insufficient iron in the placenta can cause metabolic shifts, abnormal iron profiles, and impaired brain function, potentially affecting long-term cognitive development.
Why are folate requirements higher during pregnancy?
Increased cell division and metabolism.
Placental and fetal growth.
Uterine enlargement and maternal blood volume expansion.
What is the recommended dietary allowance (RDA) for folate during pregnancy?
600 mcg dietary folate equivalents (DFE) per day, accounting for different bioavailabilities of natural folate and synthetic folic acid.
What are the 5 consequences of low folate intake during pregnancy?
Neural tube defects (NTDs): Including spina bifida and anencephaly.
Maternal megaloblastic anemia: Large, immature red blood cells.
Pre-eclampsia: High blood pressure and pregnancy complications.
Low birth weight and preterm birth.
What are dietary sources of folate?
Green leafy vegetables, legumes, oranges, fortified wheat flour, and cereals. Prenatal vitamins typically contain 1,000 mcg folic acid.
Why is vitamin B12 important during pregnancy?
B12 supports fetal brain development, DNA synthesis, and red blood cell formation.
What are the 4 risks of vitamin B12 deficiency during pregnancy?
Low birth weight and intrauterine growth restriction (IUGR).
Congenital abnormalities and neural tube defects.
Increased risk of spontaneous abortion and preterm birth.
Impaired fetal metabolic programming, increasing disease susceptibility later in life.
Why can high folic acid intake mask vitamin B12 deficiency?
Excess folic acid can correct megaloblastic anemia caused by B12 deficiency, delaying diagnosis and allowing neurological damage to progress.
What are the 3 effects of low vitamin B6 intake during pregnancy?
Increased risk of preterm birth, pregnancy loss, and reduced fertility.
What are the 4 key functions of choline during pregnancy?
Methylation nutrient metabolism.
Acetylcholine synthesis (important neurotransmitter).
Formation of phosphocholine in cell membranes.
Possible impact on child cognitive processing speed.
What is the RDA for iron during pregnancy?
27 mg/day.
Why do plant-based diets require more iron during pregnancy?
Plant-based iron (non-heme) has lower bioavailability. The RDA for iron is 1.8 times higher for those consuming plant-based diets.
How can vitamin C improve iron absorption from plant-based foods?
Vitamin C enhances non-heme iron absorption by reducing iron to a more bioavailable form.
What is Canada’s recommendation for folic acid supplementation?
All women of childbearing age should take a 0.4 mg folic acid supplement daily to prevent neural tube defects.
What is the recommended daily intake of vitamin B12 during pregnancy?
2.6 mcg/day, typically provided in prenatal supplements.
What is the role of food fortification in folate intake?
Fortification of wheat flour and cereals ensures folate intake for those who do not take supplements, helping prevent neural tube defects.
What is the tolerable upper limit (UL) for vitamin B6, and why is excess intake concerning?
UL is 30 mg/day; excessive intake can cause neurological issues.
Why are supplements essential during pregnancy?
Iron and folic acid supplementation is required to meet increased micronutrient demands for fetal development.
What is the recommended daily prenatal supplement in Canada?
A multivitamin containing:
0.4 mg folic acid.
16-20 mg iron.
2.6 mcg vitamin B12.
Which 3 nutrients are considered especially important but may be limited in the diet?
Choline, omega-3 fatty acids (DHA), and iodine.
Why does Health Canada recommend an iron-containing prenatal supplement?
Iron supports increased blood volume and fetal development.
Some women require 30 mg of supplemental iron during the 2nd and 3rd trimesters.
How can pregnant women prevent iron-induced constipation from supplements?
Increase fluid intake.
Monitor urine output and color for hydration status.
Why is alcohol completely avoided in pregnancy?
There is no known safe level of alcohol consumption, and prenatal alcohol exposure can cause fetal alcohol spectrum disorders (FASD).
