Topic 10 - PART A Flashcards
List ways in which men and women can prepare for a healthy pregnancy
1) maintain good body weight
2) Choose adequate and balanced diet
3) Be physically active
4) Regular medical care
5) Manage chronic conditions
6) Avoid harmful influences
Why is achieving a healthy body weight important prior to pregnancy?
- excess body fat in women disrupts menstrual regularity and ovarian hormone production
- overweight and obese men have low sperm counts and hormonal changes that reduce fertility
Why is it important to avoid harmful influences prior to pregnancy?
- Smoking, alcohol, drugs, and environmental contaminants can cause abnormalities, alter genes and their expression and interfere with fertility
Describe foetal development from conception and how exposure to harmful substances or malnutrition during pregnancy can affect critical periods of development.
- Zygote (<14 days): newly fertilized egg, which begins as a single cell. The germinal period lasts from conception to implantation of the zygote into uterus lining
- Embryo (week 3-9): most organ systems are established; 90% of body structures can be distinguished
- Foetus (week 10- full term): organs that form during embryonic period continue to grow and differentiate
- Critical periods: pre-programmed time periods during development when specific cells, organs, and tissues are formed or functionality is established
As soon as the embryo begins to receive nourishment from the mother through the placenta. . .
it becomes vulnerable to hazards (e.g. diseases from mother), nutritional deficiencies, and drugs / other toxins
When are abnormalities in the feotus most dangerous?
in the first few weeks when cell division is rapidly occurring
The placenta blocks all harmful substances from reaching the foetus. True or False
False
What are the 3 functions of the placenta?
- hormone and enzyme production
- nutrient and gas exchange
- removal of waste products
The placenta governs. . .
the rate of passage of nutrients and other substances in and out of the foetal circulation
What kinds of harmful substances do / do not pass through the placenta?
- alcohol, high doses of vitamins, drugs, and certain bacteria do pass through
- the placenta does act a barrier to the passage of may types of bacteria and viruses, maternal RBC, and large proteins
- the placenta prevents the mixing of maternal and foetal blood until delivery
When does the critical period for neural tube defects (NTDs) occur?
- at 17-30 days gestation
- during normal development, the embryonic neural tube undergoes a process of folding and closing to form an enclosed neural canal
Australian recommendations for folate in / before pregnancy
- folic acid supplements should be taken for at least one month BEFORE and continued for 3 months AFTER conception, in addition to consuming folate from a varied diet
- women who are planning a pregnancy require an additional 400mcg per day of FOLIC ACID in supplement form (400mcg/d from supplement +400mcg/d from food)
- the RDI increases to 600 mcg per day DURING pregnancy from foods (400 mcg/d from folic acid supplement + 600 mcg/d from food). Total is 1000mcg/d in the first trimester
Inadequate folate status is linked to . . .
the development of NTDs
Failure of the neural tube to close results in permanent disability. What are the 2 consequences.
1) Anencephaly (no brain) - occurs when closure fails high up on the neural tube (major part of the brain, skull, and scalp is missing) - usually die at birth or very quickly after
2) Spinda bifida (open spine) - occurs when closure fails lower down the neural tube
- there is a protrusion of nervous tissue with various degrees of damage to nerves
- spinal cord is not fully encased in bone so becomes vulnerable to damage - paralysis / delayed cognitive development
How can folate levels be increased?
by consuming folate-rich foods or ingesting folic acid, a synthetic compound available in dietary supplements and fortified foods
Examples of food with folic acid
- dark green leafy veg
- beans
- peanuts
- sunflower seeds
- whole grains
- liver
Why is iodine important?
essential for synthesis of the thyroid hormones
Functions of thyroid hormones
- play a vital role in the early growth + development of most organs, esp the brain
Problems caused by iodine deficiency
- mild-moderate iodine deficiency may cause cognitive, physical, and behavioural impairments of children, & in extreme cases, stunted growth (cretinism)
- iodine deficiency is an increasing problem in Australia
- studies have shown that median levels of urinary iodine (96mcg/L) are well below the level which defines sufficient intake (150mcg/L)
Iodine recommendation for women
Women who are pregnant, breastfeeding or considering pregnancy should take an iodine supplement of 150 mcg/day
