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

2. Preconception Overview: Infertility
~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

3. Preconception Overview: Miscarriage
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

4. Preconception Overview: Subfertility
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

5. 2010 Nutrition Objectives for the Nation Related to Preconception

6. 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

7. Reproductive Physiology: Ova and Women
Women born with life-time supply of ~7 million immature ova
~ ova will mature & be released during fertile years

8. Reproductive Physiology: Ova and Women
Chromosomes in ova
May be damaged by
Oxidation
Radioactive particle exposure
Aging
Women >35 years more likely to have disorders related to chromosomal defects than younger women

9. Reproductive Physiology: Sperm and Men
Sperm production begins during puberty, decreases somewhat after age 35 with production continuing to old age

10. 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

11. 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

12. 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

13. Changes in the Ovary and Uterus

14. Male Reproductive System
Interactions among hypothalamus, pituitary gland, and testes
Androgens — Testosterone
Sperm are stored in the epididymis & released in semen

15. Sources of Disruptions in Fertility
Adverse nutritional exposure
Contraceptive use
Severe stress
Infection
Tubal damage or other structural damage
Chromosomal damage

16. Factors Related to Altered Fertility

17. Nutrition-Related Disruptions in Fertility
Undernutrition
Weight loss
Obesity
High exercise levels
Intake of specific foods & food components

18. 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

19. 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 <20 or >30

20. Weight Loss and Fertility in Females
Weight loss >10-15% 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

22. 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% <normal & cease at wt >25% < normal

23. 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

24. Diet and Fertility Diet may impact hormones
Main dietary practices are vegetarian diets, low fat intake, high intakes of dietary fiber, soy, caffeine, & alcohol

25. 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.

26. Oxidative Stress, Antioxidant Status, and Fertility
Vitamin E
Vitamin C
Beta-carotene
Selenium
Found in vegetables and fruits.
Protect cells of the reproductive system, including eggs and sperm.

27. 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

28. Plant Foods and Fertility
Low-fat, high fiber linked to reduced estrogen & irregular periods
Isoflavones (from soy) decrease levels of gonadotropins, estrogen, & progesterone

29. 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

30. 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% 

31. 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
>10 drinks  66%  in conception

32. Other Factors Contributing to Infertility in Males
Antioxidant nutrients
Protect sperm from oxidative damage
Vitamin D—Low status related to infertility
Alcohol intake—toxic effect on testes
Heavy metal exposure
Lead—impacts testes & sperm
Mercury—decreases sperm & semen
Halogens

33. Other Factors Contributing to Infertility in Males
Glycols—from 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

34. Nutrition-Related Side Effects of Contraceptives

35. Other Preconceptual Nutrition Concerns
Very-early-pregnancy nutrition exposures
Folate status prior to conception
Neural tube defects
Recommended dietary intakes for preconceptional women

36. Nutritional Disruptions

37. MyPyramid Recommendations for Preconceptional Women

38. Model Preconceptional Nutrition Programs
Preconceptional benefits of WIC
Decreasing iron deficiency in preconceptional women in Indonesia
Preconception care: Preparing for pregnancy

39. CDC’s 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

40. 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

41. 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

42. 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

44. 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 2003;25(1) Posted on Blackboard