Chapter 2 Preconception Nutrition

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Chapter 2Preconception Nutrition
Nutrition Through the Life Cycle Judith E. Brown
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Preconception OverviewInfertility

• 15 of couples are infertile
• 40 of couples diagnosed as infertile will
  conceive within 3 years without use of technology
• Healthy couples have a 23 to 30 chance of
  conception within a given menstrual cycle

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Preconception OverviewMiscarriage

• Miscarriage Loss of conceptus in 1st 20 weeks of
  pregnancy
• Causes of miscarriages
• Defect in fetus
• Maternal infection
• Structural abnormalities of uterus
• Endocrine or immunological disturbances

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Preconception OverviewSubfertility

• Subfertility Reduced level of fertility
  characterized by unusually long time for
  conception
• 18 of couples are subfertile
• Examples
• Having multiple miscarriages
• Sperm abnormalities
• Infrequent ovulation

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2010 Nutrition Objectives for the Nation Related
to Preconception
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Reproductive Physiology

• Development of female male reproductive systems
  
• Begins during first months after conception
• Continue to grow develop through puberty
• Capacity for reproduction
• Establishes during puberty when hormonal changes
  stimulate maturation of reproductive system

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Reproductive PhysiologyOva and Women

• Women born with life-time supply of 7 million
  immature ova
• 400-500 ova will mature be released during
  fertile years

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Reproductive PhysiologyOva and Women

• Chromosomes in ova
• May be damaged by
• Oxidation
• Radioactive particle exposure
• Aging
• Women gt35 years more likely to have disorders
  related to chromosomal defects than younger women

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Reproductive PhysiologySperm and Men

• Sperm production begins during puberty,
  decreases somewhat after age 35 with production
  continuing to old age

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Hormonal Effects During the Menstrual Cycle

• Gonadotropin-releasing hormone (GnRH)
• Stimulates pituitary to release FSH and LH
• Follicle-stimulating hormone (FSH)
• Stimulates maturation of ovum sperm
• Luteinizing hormone (LH)
• Stimulates secretion of estrogen, progesterone,
  testosterone

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Hormonal Effects During the Menstrual Cycle

• Estrogen
• Stimulates release of GnRH in follicular phase
  follicle growth maturation of follicle
• Stimulates vascularity storage of glycogen
  other nutrients within uterus
• Progesterone
• Prepares uterus for fertilized ovum, increases
  vascularity of endometrium, stimulates cell
  division of fertilized ova

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Two Phases of Menstrual Cycle

• Follicular Phase(first half of menstrual cycle)
• Follicle growth maturation
• Main hormones GnRH, FSH, estrogen,
  progesterone
• Luteal Phase(last half of menstrual cycle)
• After ovulation
• Formation of corpus luteum
• ? in estrogen progesterone stimulate menstrual
  flow
• Postaglandins cramps

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Changes in the Ovary and Uterus
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Male Reproductive System

• Interactions among hypothalamus, pituitary gland,
  and testes
• Androgens Testosterone
• Sperm are stored in the epididymis released in
  semen

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Sources of Disruptions in Fertility

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

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Factors Related to Altered Fertility
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Nutrition-Related Disruptions in Fertility

• Undernutrition
• Weight loss
• Obesity
• High exercise levels
• Intake of specific foods food components

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Undernutrition and Fertility

• Chronic undernutrition
• Primary effect birth of small frail infants
  with high likelihood of death in the first year
  of life
• Acute undernutrition
• Associated with a dramatic decline in fertility
  that recovers when food intake does

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Body Fat and Fertility

• Decreased fertility seen with low or high body
  fat due to alterations in hormones
• Estrogen leptin
• Levels increased with high body fat reduced
  with low body fat
• Both extremes lower fertility
• Infertility lower with BMI lt20 or gt30

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Weight Loss and Fertility in Females

• Weight loss gt10-15 of usual weight decreases
  estrogen
• Results in amenorrhea, anovulatory cycles,
  short or absent luteal phases
• Treatment with fertility drug Clomid not
  effective in underweight women

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Weight Loss and Fertility in Males

• Studies from World War II showed 50 decrease in
  male fertility during starvation
• Sperm viability motility decrease with wt. 10
  to 15 ltnormal cease at wt gt25 lt normal

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Exercise and Infertility

• Adverse effects of intense physical activity
• Delayed age at puberty
• Lack menstrual cycles
• Appear to be related to hormonal and metabolic
  changes
• Related to caloric deficits
• Reduced levels of estrogen
• Low levels of body fat
• Decreased bone density

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Diet and Fertility

• Diet may impact hormones
• Main dietary practices are vegetarian diets, low
  fat intake, high intakes of dietary fiber, soy,
  caffeine, alcohol

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Oxidative Stress, Antioxidant Status, and
Fertility

• Oxidative stress in men
• Decreases sperm motility
• Reduces ability of sperm to fuse with an egg
• Oxidative stress in women
• Harm egg and follicular development
• Interfere with corpus luteum function
• Interfere with implantation of the egg.

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Oxidative Stress, Antioxidant Status, and
Fertility

• Antioxidants.
• Vitamin E
• Vitamin C
• Beta-carotene
• Selenium
• Found in vegetables and fruits.
• Protect cells of the reproductive system,
  including eggs and sperm.

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Oxidative Stress, Antioxidant Status, and
Fertility

• Zinc status and Fertility in Men.
• Plays important roles
• In the reduction of oxidative stress
• In sperm maturation
• In testosterone synthesis
• Has been investigated for potential role in
  infertility

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Plant Foods and Fertility

• Low-fat, high fiber linked to reduced estrogen
  irregular periods
• Isoflavones (from soy) decrease levels of
  gonadotropins, estrogen, progesterone

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Preconception Iron Status, Fertility,
Pregnancy Outcome

• Rate of infertility lower in women who use iron
  supplements or iron from plant foods
• Pre-pregnancy iron deficiency linked to preterm
  delivery low iron status of infant
• 1/2 of U.S. women enter pregnancy with
  inadequate iron stores

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Caffeine and Fertility

• Caffeine appears to prolong time to conception
• Daily caffeine intake reduction in conception
  is
• 300 mg results in 27 ?
• 500 mg results in 50 ?

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Alcohol and Fertility

• Alcohol may decrease estrogen testosterone
  levels or disrupt menstrual cycles
• Studies on weekly drinks consumed show
• 1-5 drinks ? 39 ? in conception
• gt10 drinks ? 66 ? in conception

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Other Factors Contributing to Infertility in Males

• Antioxidant nutrients
• Protect sperm from oxidative damage
• Vitamin DLow status related to infertility
• Alcohol intaketoxic effect on testes
• Heavy metal exposure
• Leadimpacts testes sperm
• Mercurydecreases sperm semen
• Halogens

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Other Factors Contributing to Infertility in Males

• Glycolsfrom antifreeze
• Hormones
• synthetic estrogens, DDT, PEs, PCBs
• Heat
• sperm count can be reduced by elevating the
  temperature of the scrotum and testes
• Steroid abuse
• side effects include atrophy of testicles,
  absence of sperm, and decreased libido

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Nutrition-Related Side Effects of Contraceptives
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Other Preconceptual Nutrition Concerns

• Very-early-pregnancy nutrition exposures
• Folate status prior to conception
• Neural tube defects
• Recommended dietary intakes for preconceptional
  women

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Nutritional Disruptions
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MyPyramid Recommendations for Preconceptional
Women
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Model Preconceptional Nutrition Programs

• Preconceptional benefits of WIC
• Decreasing iron deficiency in preconceptional
  women in Indonesia
• Preconception care Preparing for pregnancy

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CDCs Preconceptional Health Initiative

• Recommends that primary health care visits
  include
• Preconception health pregnancy outcome
  education
• Screening for vaccination, weight, iron folate
  status
• Assessment of alcohol use
• Management of diabetes celiac disease

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Another CDC Recommendation

• Each woman, man, couple should make a
  reproductive life plan that includes whether
  when they want to have children how they will
  maintain their reproductive health.
• Centers for Disease Control Prevention, 2006

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Nutrition Programs and Services Delivery Before
Pregnancy

• Recently developed nutrition care standards
• By the American Dietetic Association
• Called Nutrition Care Process
• Part of new technology-based systems
• To facilitate health-services delivery
• Cost evaluation
• Electronic charting
• Coding and outcome measurement

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Nutrition Programs and Services Delivery Before
Pregnancy

• The Nutrition Care Process
• Step 1 Nutrition assessment
• Step 2 Nutrition diagnosis
• Step 3 Nutrition intervention
• Step 4 Nutrition monitoring and evaluation
• See Table 2.10 for summary

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Suggested Readings

• Before Your Pregnancy A 90-Day Guide for
  Couples on How to Prepare for a Healthy
  Conception. By Amy Ogle, MS,RD and Lisa
  Mazzullo, MD
• Integrated Perinatal Health Framework
• A Multiple Determinants Model with a Life Span
  Approach by Dawn P. Misra, PhD, Bernard Guyer,
  MD, Adam Allston, MPH
• Am J Prev Med 200325(1) Posted on Blackboard