Pre-conception Nutrition Flashcards
Infertility
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
Miscarriage
Loss of conceptus in first 20 weeks of pregnancy
- defect in fetus
- maternal infection
- structural abnormalities of uterus
- endocrine of immunological disturbances
Subfertility
Reduced level of fertility characterised by unusually long time for conception- 18% of couples
- having multiple miscarriages
- sperm abnormalities
- infrequent ovulation
Menstrual cycle
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
Women’s reproductive system
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
Hormonal effects during the menstrual cycle
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
Ovary
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.
Oviduct
One of a pair of cilliated channels through which oocytes are conducted from an ovary to the uterus; usual site of fertilisation
Uterus
Chamber in which embryo develops; its narrowed down portion (the cervix) secretes mucus that helps sperm move into uterus and that bars many bacteria
Myometrium
Thick muscle layers of uterus that stretch enormously during pregnancy
Endometrium
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
Men and the reproductive system
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
Sources of disruption in fertility
Adverse nutritional exposure Contraceptive use Severe stress Infection Tubal damage or other structural damage Chromosomal damage
Altered fertility: males & females
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
Altered fertility: females
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
