1. Pregnancy and Fetal Development John J. Parrish

2. Placental Functions Placenta Chemical ProtectionPhysical Protection EndocrineExchange

3. Placental Functions Placenta Chemical ProtectionPhysical Protection EndocrineExchange Gas Nutrients Waste products Immunosupression Prevents infiltration by maternal defenses Filters toxins Shock Absorber Transient Estrogen Progesterone HCG eCG PL

4. Similarities in Early Development MANPIGBIRD

5. Developmental HorizonsMareCowEweSowWoman Germ layers13-141410-147-810-14 Open neural tube2015-2113 Fusion of chorioamniontic folds181716 Heart beat apparent2421-22201625 Limb buds visible242528-3517-1828 Cotelydons first appear30 Eye differentiation4030-4542-4921-28 Birth340280147-155112266 Developmental Features Critical Organ Systems Develop Early!

6. Fetal Development in the Human 0481216202428323640 Ovulation Length (cm) 0 10 20 30 40 50 Age of Fetus (weeks since last menstruation) 1 2 3 0 Weight (kg) Parturition

7. Crown Rump Estimates of Age Crown rump length Length femur, radius or tibia Circumference of head

8. Factors Influencing Fetal Growth Genetics Species Breed Litter size Genotype Genetics Species Breed Litter size Genotype Fetal Hormones Thyroid Insulin Growth hormone Fetal Hormones Thyroid Insulin Growth hormone Environment Mother Nutrition Size, Parity Placenta Blood flow Size Environment Mother Nutrition Size, Parity Placenta Blood flow Size

9. Factors Influencing Fetal Growth Genetics Species Breed Litter size Genotype Genetics Species Breed Litter size Genotype

10. Factors Influencing Fetal Growth Genetics Species Breed Litter size Genotype Genetics Species Breed Litter size Genotype

11. Genetics Species Breed Litter size Genotype Genetics Species Breed Litter size Genotype Factors Influencing Fetal Growth

12. Genetics Species Breed Litter size Genotype Genetics Species Breed Litter size Genotype Factors Influencing Fetal Growth Certains lines of animals may grow faster.

13. Factors Influencing Fetal Growth Environment Mother Nutrition Size, Parity Placenta Blood flow Size Environment Mother Nutrition Size, Parity Placenta Blood flow Size

14. Factors Influencing Fetal Growth Environment Mother Nutrition Size, Parity Placenta Blood flow Size Environment Mother Nutrition Size, Parity Placenta Blood flow Size

15. Factors Influencing Fetal Growth Fetal Hormones Thyroid Insulin Growth hormone Fetal Hormones Thyroid Insulin Growth hormone Skeletal and muscular development Increased energy substrate availability and stimulates placental growth Stimulates fetal growth

16. Uterine Size Changes During Pregnancy Hyperplasia » Increase in # of cells Hypertrophy » Increase in size of cells Stretching

17. Placenta Liver Left AtriumLungsRight Atrium Foramen Ovale Foramen Ovale Ductus Venosus Ductus Venosus Ductus Arteriosus Ductus Arteriosus Aorta Umbilical Arteries Umbilical Vein Portal Vein Vena Cava Head and Heart Tissues

18. Relative P 4 and E 2 Weeks of Gestation Ovulation

19. Relative P 4 and E 2

20. Weeks of Gestation Ovulation

23. Relative P 4 and E 2 Weeks of Gestation Ovulation

25. Progesterone Maintains Pregnancy!

26. Progesterone is Essential To Maintain Pregnancy Corpus LuteumPlacenta Sow3.8 mo3.8 mo(none) Cow9 mo6 - 8 mo Ewe5 mo50 d Mare11 mo70 d Human9 mo60-70 d SpeciesGestationPlacental LengthTakeover

27. Other Species in Which Placenta Does not Take-over Progesterone Production Bitch Queen Alpaca, Llama, Camel Rabbit Goat