Human Pregnancy

1. Human Pregnancy

2. How Long is the Human Pregnancy?

3. Fertilization

4. Fertilization

5. Pre-embryo Development Day 1 Fertilization Day 3 Morula Day 4 Early Blastocyst Day 5 Late Blastocyst

6. Implantation Days 7- 10

7. Ectopic pregnancy

8. Success Rates • 30% of all fertilized eggs fail to implant • 70% implants • 20% miscarriage • 1% stillborn • 79% live births (55% of all fertilized eggs) • 2% major congenital defects • 11% minor congenital differences • 87% healthy babies

9. . • Blastocytes produce • Proteases • Break down cells of the uterine endomitrium • Human Chorionic Hormone (HCG) • Maintain the Corpus Luteum (progesterone production)

10. Placenta formation

11. Hormones

12. Placenta • There is no exchange of blood between mother and fetus • Most substances are filtered • There are some exceptions • Some virus (HIV • Some bacteria (Syphilis) • Alcohol, cocaine, other drugs • The effect of those substances will depend of the structure developing at the time and the dose. • The Placenta plays a role in preventing the mother’s immunological system from rejecting the embryo. • Some times cells are exchanged!

13. Placenta separate mother / fetus blood

14. Microchimerism 20% of adults have cells from their mothers 50% women (pregnancy past) have cells from the fetus decades after the pregnancy Scientists have found a correlation between microchimerism and autoimmune disorders

15. First trimester Embryo development 4 weeks: The neural tube along your baby's back is now closed. Head, mouth, liver, and intestines begin to take shape. 7-8 weeks: can detect heartbeat, spinal canal, arms/legs, fingers/toes now officially described as a fetus. Ears are moving up and to the side of the head eyes are moving closer together. External genitalia will develop into a recognizable penis or clitoris and labia majora.

16. Different Species

17. Size

18. First trimester Mother’s symptoms • Secondary amenorrhea (spotting) • Morning sickness • Tenderness of breasts (darkening areola) • Positive pregnancy test (hCG) • Increase size abdomen • Softening of the cervix • Increased frequency of urination • Detection of heart beat • Visualization of the fetus (ultrasound)

19. 2nd Trimester • Fingernails have grown on the tips of the fingers and toes, and the fingers and toes are fully separated. • The fetus goes through cycles of sleep and wakefulness. • Skin is wrinkly and red, covered with soft, downy hair (called lanugo). • Hair is growing on the head of the fetus. • Fat begins to form on the fetus. • Eyelids are beginning to open and the eyebrows and eyelashes are visible. • Fingerprints and toeprints have formed. • Rapid growth is continuing in fetal size and weight. • The 20th week marks the halfway point of the pregnancy.

20. 3th Trimester • Baby's eyes open • Movement is more forceful • Baby packs on pounds • Downy hair falls off • Baby detects light • Protective coating gets thicker • Rapid growth continues • Baby can suck • Organ function continues to improve • Placenta provides antibodies

21. 2nd-3rd TrimesterMother’s symptoms • Second trimester movement felt; heightened sense of well-being • Third trimester increased size; greater discomfort

22. The Experience of Pregnancy • For the man • ecstasy to ambivalence to fearfulness • sense of separation • concern about financial impact • active involvement helps

23. Sexual interaction during pregnancy • inhibited during 1st & 3rd trimesters; or progressive decline • some women experience increases in desire • no restrictions on sexual activity or orgasm unless woman is at risk • modified positions often needed

24. Chromossomic Birth Defects • Rates increase with age of parents (particularly mother) • Example Down Syndrome • 1/1000 before 35 years old • 1/200 – 35 years old • 1/15 – 45 years old

25. Environmental Birth Defects • Most substances are filtered by the placenta • There are some exceptions • Some virus (HIV • Some bacteria (Syphilis) • Alcohol, cocaine, other drugs • Fetal Alcohol Syndrome is the most common cause of mental retardation in the US) • The effect of those substances will depend of the structure developing at the time and the dose. • Some birth defects have being associated with malnutrition/ vitamin deficiency (Spina bifida)

26. Detection of birth defects • Alpha-fetoprotein levels • Acetylcholinesterase • Estriol and beta-human chorionic • Inhibin A • Ultrasound • Chorionic villus sampling (10 weeks) • Amniocentesis (14 to16 weeks)

27. Labor first stage • Begins with the onset of contractions and changes in the cervix and ends when your cervix is fully dilated.This stage is divided into two phases: • early (or latent) cervix gradually effaces (thins out) and dilates (opens). • active labor: cervix begins to dilate more rapidly and contractions are longer, stronger, and closer together.

28. Labor Second Stage • begins once you're fully dilated and ends with the birth of your baby. This is sometimes referred to as the "pushing" stage.

29. LaborThird Stage • Begins right after the birth of your baby and ends with the separation and subsequent delivery of the placenta.

30. Miscarriage • occurs in first 20 weeks • emotional impact can be significant • couple needs grief-support

31. Abortion • Elective abortion Approximately 25% of U.S. pregnancies end in elective abortion; 1% occur after 20 weeks

32. Elective abortion • Procedures • medical abortion (medication only until 7 weeks) • suction curettage in 90% of pregnancies in the US • dilation & evacuation • late-term abortion procedures • illegal abortions

33. Abortion controversy • historical overview • Early American law allowed abortion until quickening • 1973 Roe vs. Wade • 1977 Hyde Amendment • State restrictions or limitations • Waiting period, parent notification • Mexico City Policy (international gag order)

34. Abortion controversy (cont.) • current debate • majority of Americans believe abortion should remain legal • pro-life goals • pro-choice goals • recent debate is more violent • ethnic differences in views toward abortion