Pre-conception Nutrition

Question 1

Infertility

Answer 1

15-17% of couples are infertile but 40% will conceive within 3 years w/o technology
Healthy couples: 20-25% chance of conception within a given menstrual cycle

Question 2

Miscarriage

Answer 2

Loss of conceptus in first 20 weeks of pregnancy

• defect in fetus
• maternal infection
• structural abnormalities of uterus
• endocrine of immunological disturbances

Question 3

Subfertility

Answer 3

Reduced level of fertility characterised by unusually long time for conception- 18% of couples

• having multiple miscarriages
• sperm abnormalities
• infrequent ovulation

Question 4

Menstrual cycle

Answer 4

Follicular phase

• follicle growth and maturation
• main hormones GnRH, FSH, oestrogen and progesterone

Luteal phase

• after ovulation
• formation of corpus luteum
• decreased oestrogen and progesterone stimulate menstrual flow
• prostaglandins and cramps

Question 5

Women’s reproductive system

Answer 5

Forms during first months after conception. Pre conception exposure can affect this growth- eg. Excessive alcohol, pain fumes and drug use
Continues to grow and develop through puberty
Capacity for reproduction establishes during puberty when hormonal changes stimulate maturation of reproductive system
Chromosomes in ova may be damaged by oxidation, radioactive particle exposure, aging
Women older than 35 more likely to have chromosomal damage

Question 6

Hormonal effects during the menstrual cycle

Answer 6

Gonadotropin releasing hormone stimulates pituitary gland to release follicle stimulating hormone and lutenizing hormone

FSH stimulates maturation of ovum and sperm

Lutenizing hormone stimulate secretion of oestrogen, progesterone and testosterone

Oestrogen stimulates release of GnRH in follicular phase and follicle growth and maturation. Also stimulates vascularity and storage of glycogen and other nutrients in uterus

Progesterone prepares uterus for fertiliser ovum, increases vascularity of endometrium and stimulates cell division of fertilised ova

Question 7

Ovary

Answer 7

One of a pair of primary reproductive organs in which oocytes (immature eggs) form and mature, produces hormones (estrogens and progesterone), which stimulate maturation of oocytes, formation of corpus luteum (a glandular structure) and preparation of the uterine lining for pregnancy.

Question 8

Oviduct

Answer 8

One of a pair of cilliated channels through which oocytes are conducted from an ovary to the uterus; usual site of fertilisation

Question 9

Uterus

Answer 9

Chamber in which embryo develops; its narrowed down portion (the cervix) secretes mucus that helps sperm move into uterus and that bars many bacteria

Question 10

Myometrium

Answer 10

Thick muscle layers of uterus that stretch enormously during pregnancy

Question 11

Endometrium

Answer 11

Inner lining of uterus, site of implantation of blastocyst (early embryonic stage) becomes thickened, nutrient packed and highly vascularised tissue during a pregnancy; gives rise to maternal portion of placenta, an organ that metabolically supports embryonic and feral development

Question 12

Men and the reproductive system

Answer 12

Spent production begins during puberty, declines after 35 but continues into old age
Interactions among hypothalamus, pituitary gland and testes
Androgens- testosterone
Sperm stored in the epididymis and released in semen. Takes approx 72-90 days to mature- eg if trying to conceive, may not be optimal for another 2-3 months

Question 13

Sources of disruption in fertility

Answer 13

Adverse nutritional exposure 
Contraceptive use
Severe stress 
Infection 
Tubal damage or other structural damage 
Chromosomal damage

Question 14

Altered fertility: males & females

Answer 14

Weight loss > 10-15% of normal weight 
Inadequate antioxidant status (selenium, vit C and E) 
Excessive fat, high central 
Extreme exercise 
High alcohol intake 
Endocrine disorders (hypothyroidism, cushings disease) 
Structural abnormalities of reproductive tracts 
Coeliac disease
Chromosomal abnormalities 
Oxidative stress 
Severe psychological stress 
Infection (STI) 
Diabetes, cancer other disorders 
Some medications

Question 15

Altered fertility: females

Answer 15

Oral contraception in last two months 
Anorexia nervosa or bulimia nervosa 
Vegan diet
Age >35 
Metabolic syndrome 
Pelvic inflam disease (PID) 
Endometriosis
Polycystic ovary syndrome 
Poor iron stores

Question 16

Altered fertility: males

Answer 16

Inadequate zinc status 
Heavy metal exposure (lead, mercury, cadmium, manganese) 
Halogen (in pesticides) and glycol (in anti freeze) exposure 
Estrogen exposure (in DDT, PCBs) 
Sperm defects (quality and motility) 
Excessive heat to testes 
Steroid abuse 
High intake of soy foods