W10 Nutrition in pregnancy importance of folic acid and thyroid hormone

Question 1

Neural Tube Defects (NTDs)

Answer 1

NTDs affect the brain and spinal cord, and are among the most common of the congenital anomalies
* Ancephaly: is a lethal condition and is often an isolated, non-syndromic anomaly.
* Encephalocele: is characterised by a pedunculated or sessile cystic, skin-covered lesion protruding through a defect in the cranium (skull bone)
* Spina bifida: is characterised by herniation of meninges and spinal cord or meninges. Lesion can be open or closed
* Long-term consequences for the baby’s health

• Cosmetic concerns
• Psychological impact

Question 2

Prenatal care guidelines for NTD prevention

Answer 2

• Women who wish to become pregnant should be advised to take supplementation with folic acid before conception and until week 12 of pregnancy
• It is recommended to take folic acid while you’re trying for a baby (ideally for 3 months before) and during the first 12 weeks of pregnancy
• At risk subgroups require a daily dose of 5 mg of folic acid. This is higher than the usual pregnancy dose and is only available on prescription
• a high risk of conceiving a child with a neural tube defect
• previously had an infant with a neural tube defect
• receiving antiepileptic medication
• diabetes
• sickle-cell disease
• BMI is 30 or above
• Regular follow-up and monitoring is necessary

Question 3

Why is folic acid needed in pregnancy?

Answer 3

• The neural tube, which later forms the brain and spinal cord, develops during the early weeks of pregnancy
• Folic acid needed for DNA methylation and histone modification deficiency impacts expression of genes involved in early formation of the nervous system
• By ensuring adequate folic acid intake, neural tube defects such as spina bifida (incomplete closure of the spinal cord)
  and anencephaly (underdeveloped brain and skull) can be reduced

Types of folate include:
* Dihydrofolate (DHF)
* Tetrahydrofolate (THF)
* 5, 10-Methylene-THF
* 5-Methyl-THF or 5-MTHF

Folic acid is the ideal form of folate to use for food fortification. It is more stable than natural sources of folate, which can easily
be broken down by heat and light.

Question 4

Thyroid hormones play a crucial role in pregnancy for both the mother and the developing fetus

Answer 4

• 1. Fetal Brain Development: Adequate levels of thyroid hormone are necessary for the proper development of the fetal brain and nervous system.
     Thyroid hormone influences the growth and maturation of neurons and supports cognitive function.
• 2. Metabolism and Energy Production: Thyroid hormones regulate
     metabolism, including the conversion of nutrients into energy. During
     pregnancy, the metabolic demands increase, and thyroid hormones help
     ensure that the mother has sufficient energy to support the growing fetus
• 3. Hormone Regulation: Thyroid hormones help regulate the production and
     activity of other hormones in the body. They play a role in maintaining a
     balanced hormonal environment during pregnancy, which is important for a
     healthy pregnancy
• 4. Maternal Health: Healthy thyroid function is crucial for the overall well-
     being of the mother during pregnancy. Thyroid hormones help support
     proper cardiac function, digestion, and the immune system
• 5. Prevention of Complications: Thyroid disorders during pregnancy, such as
     hypothyroidism or hyperthyroidism, can increase the risk of complications.
     Untreated thyroid disorders can lead to issues like preterm birth, low birth
     weight, preeclampsia, and developmental problems in the baby

Question 5

Thyroid hormones play a crucial role in pregnancy for both the mother and the developing fetus

Answer 5

• The thyroid enlarges slightly in healthy women
  during pregnancy, but usually not enough for a
  health care professional to feel during a physical
  exam
• Serum levels of TSH might be lower in pregnant
  women during early gestation than levels outside
  the pregnancy setting, due to increased production
  of thyroid hormone and stimulation from hCG
• Levothyroxine treatment for maternal subclinical
  hypothyroidism in pregnancy remains controversial
  because currently available studies have not shown
  a clear benefit of treatment on obstetric or child
  neurodevelopmental outcomes
• Clinical hypothyroidism needs to be managed
  pregnancy will be consultant lead Thyroxine checked
  4-6 weeks

Question 6

Newborn blood spot test

Answer 6

• Newborn blood spot screening involves taking a blood sample to find out if your baby has 1 of 9 rare but serious health conditions
• When baby is 5 days old, a prick their heel and collection of 4 drops of blood on a special card is performed
• Sickle cell disease
• Cystic fibrosis
• Congenital hypothyroidism
• Phenylketonuria (PKU)
• Medium-chain acyl-coa dehydrogenase
  deficiency (MCADD)
• Maple syrup urine disease (MSUD)
• Isovaleric acidaemia (IVA)
• Glutaric aciduria type 1 (GA1)
• Homocystinuria (pyridoxine unresponsive)
  (HCU)
• Severe combined immunodeficiency (SCID)

Question 7

Developmental origins of health and disease (DOHaD)

Answer 7

The developmental origins of the health and disease hypothesis (DOHaD) propose a link between periconceptual, fetal, and early infant phases of life and the long-term development of metabolic disorders

Increased incidence of non-communicable diseases e.g. CHD, diabetes, PCOS, hypertension, cancer, psychological disorders etc….

Question 8

Animal studies

Answer 8

Effect of maternal
* Nutrition
* Parity
* Age
* Alcohol consumption
* Sedentary lifestyle
* Smoking
* Alcohol
* Socioeconomic adversity (stress)
* Microbiome
* Mode of delivery

Question 9

Transgenerational epigenetic modifications

Answer 9

Not just undernutrition!!!
* Adverse maternal conditions during the pre- and perinatal period can cause long-term
transgenerational epigenetic modifications in the offspring that mediate susceptibility to
cardiometabolic disease
* Rare regulatory sequences that escape systematic DNA demethylation and others that are able to maintain histone marks in the primordial germ cells represent a potential mechanism for non-imprinted transgenerational epigenetic inheritance
* Role for epigenetics in multigenerational
transmission of damaged oocyte mitochondria leading to developmentally programmed obesity and associated cardiometabolic disease