Preconception Physiology and Nutrition

Fertility and Conception Terminology

Fertility –

Infertility –

Fecundity –                                             Infecundity –

Miscarriage –

Subfertility – reduced level of fertility (women with multiple miscarriages,    men with sperm abnormalities)

Endocrine – system of ductless glands – thyroid, adrenals, ovaries, testes – that produce secretions affecting body function

_____% western couples childless – infecund

Healthy couples –_____ chance of pregnancy within menstrual cycle

____% of diagnosed pregnancies end in miscarriage

_____% of U.S. couples subfertile

____% of adults at healthy weight

Decrease obesity in adults to ____%

Decrease Fe deficiency anemia in children and women

Decrease babies born with neural tube defects and birth defects

Increase women receiving preconception counseling

Reproductive systems begin developing during pregnancy (fetal development) and continue until puberty

Females born with:

Males born with:

Capacity for reproduction set during puberty

Hormonal changes effect maturity of reproductive system

Menstrual cycle

~ 4 week interval in which hormones direct build up of uterus wall for implantation of fertile egg

Build up – blood and nutrients

Facilitated by hormonal activity

E_strogen – ovaries, fat cells, corpus luteum

GnRH (gonadotropin releasing hormone) -- hypothalamus

FSH (follicle stimulating hormone)– pituitary

LH (luteinizing hormone) – pituitary

Progesterone – ovary

On going process of interactions among hypothalamus, pituitary and testes;

Fluctuating levels of GnRH signal release of LH and FSH from pituitary, which triggers production of testosterone from testes

Testosterone stimulates maturation of sperm (70-80days); when mature, are transported to the epididymus. Then stored until released.

1.Undernutrition

.

2.Body fat

BMI < ____ effects fertility rate, may be due to decreased estrogen

BMI > _____ effects fertility, may be due to increased estrogen

        3. Exercise

Exercise with weight loss of > ______% can cause amenorrhea, menstrual cycles with no ovulation or shortened luteal phase

Exercise may also delay onset of puberty with lack of menstrual cycles

4.Diet

*Vegetarian Diets may decrease circulating estrogen concentrations, cause irregular
   periods; high fiber diets may have same effect;

*< ___% kcals from fat may lengthen menstrual cycles;

*High carotenoid intake lead to carotemia and decreased fertility;

*Caffeine – >_____mg / day may lengthen time to conceive
    1 cup (8oz) coffee = _____mg caffeine
    12 oz cola = ____mg caffeine
    1 cup chocolate milk = ____mg caffeine

*Alcohol – may decrease fertility; main risk is FAS in infant

Pelvic Inflammatory Disease and STDs decrease fertility

Endometriosis decreases fertility

Past hx of abortions may decrease  fertility

1.Weight loss -

Decreased sperm viability and motility when weight ____% below normal; No sperm production when at ___% below normal weight.

2.Zinc – low dietary Zn status showed decrease in semen volume; during puberty a Zn defienciency can lead to hypogonadism (decreased sexual development); is reversible with adequate Zn intake.

3.___________ – selenium, vits C and E, beta- carotene protect sperm DNA from oxidative damage and promote normal sperm function and motility

4.Alcohol intake – impaired fertility common in alcoholics related to toxic affects on testes; light to moderate intake does not appear to affect fertility

5.Heavy metals – lead and mercury exposure decrease sperm production

6.Occupational exposure to __________ (in pesticides) and ________ (in antifreeze) decrease sperm production

7.Heat - high temp of scrotum can decrease sperm count

8.Hormones and steroid abuse - testicular atrophy, low sperm count, decrease sex drive

blood concentrations:

____________ decreases in blood while Cu increases, which may increase risk for venous thromboembolism (blood clotting)

Depo-Provera (DMPA): given every 3 months. Side effects:
 

Norplant- can cause irradic bleeding and weight gain, head aches; for those who believe life begins at conception choose not to use this method since it prevents the implant of an already fertilized egg.

Use food guide pyramid for balanced diet and varied food intake

Obtain normal weight

Consume _____mcg folate/d

Avoid excessive vitamin A intake < _______

Avoid lead – high levelsà mental retardation

Consume RDA for I and Fe

Avoid:

Test for Diabetes – uncontrolled blood sugarà many complications

1.Premenstrual Syndrome

_____% of women suffer from some PMS symptoms – onset usually during luteal phase, and ends with onset of menstruation;

Symptoms –

Treatment – decrease caffeine, increase exercise, Mg, B6, Ca supplements, herbal remedies (black cohosh and vitex, but not if wanting to conceive).

In men, impairs fertility due to hormonal changes in (sex hormone binding globulin) SHBG and reduced sperm count;

In women, decreased SHBG, and increased estrogen, blood glucose or insulin levels, and may trigger polycystic ovary syndrome;

Central body fat – women ______ as likely to conceive if waist is >____ inches;

Weight loss 1^st therapy – losses of ______lbs can be successful

   3.Eating Disorders

Anorexia nervosa and bulimia related to menstrual irregularities, Infertility, due to hormonal changes, low body fat, and low dietary fat intake, and excessive exercise. Resumption of normal eating habits and weight gain usually reverse fertility status

Must control blood glucose levels – need to maintain in normal range before conception and pregnancy; high blood sugar in 1^st 2months can cause miscarriage or congenital abnormalities;

Regulate blood sugar with diet, exercise and insulin. Important to maintain normal weight

5. Polycystic Ovary Syndrome (PCOS)

Also called Syndrome X: Characterized by:

Insulin resistance, high blood insulin, high testosterone levels, obesity, high BP, menstrual dysfunction like amenorrhea; high blood TG, low HDL and LDL, increase in body hair and acne;

At risk for DM, hypertension, and heart disease; Need wt loss and increased exercise.

PKU – dx by high phenylalanine found in the urine. Dietary control of phenylalanine intake is crucial!   >90% mothers with uncontrolled PKU have mentally retarded infants.

Genetic disease – low levels or lack of phenylalanine hydroxylase to convert  phenylalanine to tyrosine, so phenylalanine pools in blood. High concentrations of phenylalanine in blood early in pregnancy causes impaired CNS development.

 

Genetic disease causing sensitivity to gliadin  found in wheat, rye, oats and barley. diagnosis often delayed. Associated with infertility in both sexes.

Causes fat malabsorption and other food components when gluten is consumed, due to a flattening of intestinal lining. Pregnant women need adequate vit & min and essential fatty acids to ensure a healthy pregnancy and reduced risk of miscarriage or fetal growth restriction.