1 / 32

Prenatal Development

Prenatal Development. Haffner, W. J. J.(2007). Development before birth. In Batshaw, M. L., Pelligrino, L. & Roizen N. J. (Eds.). Children with disabilities (6 th ed.). (pp. 23-34). Baltimore, MD: Paul H. Brookes Publishing Company.

garrison-neal
Download Presentation

Prenatal Development

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Prenatal Development Haffner, W. J. J.(2007). Development before birth. In Batshaw, M. L., Pelligrino, L. & Roizen N. J. (Eds.). Children with disabilities (6th ed.). (pp. 23-34). Baltimore, MD: Paul H. Brookes Publishing Company. Moore, K. L., & Persaud, T. V. N. (1993). The developing human: Clinically oriented embryology (5th ed.). Philadelphia, PA: W. B. Saunders Company. Revised June 2008 Development of Young Children with Disabilities#872.514 (61)Carol Ann Heath

  2. Pregnancy • Dating the pregnancy • EGA- estimated gestational age (14 days longer than conceptional age, includes time between LMP and ovulation) • LMP- menstrual age is the time from the first day of the last menstrual period

  3. Fertilization • If sexual intercourse occurs near the time of ovulation when the mature ovum (egg) is released, conception can occur.

  4. Average duration of pregnancy is 280 days, or 40 weeks • EDD (estimated due date) = EDC (estimated date of confinement) • EDD- add 7 days to first day of LMP (last menstrual period) and subtract 3 months

  5. Preterm delivery- prior to 38 complete weeks EGA (estimated gestational age) • Full term- between 38 and 42 weeks EGA • Post term birth- EGA greater than 42 weeks

  6. Birth • A child is born • Preceding months are complex and numerous steps • The egg is fertilized and implants • In-utero development occurs rapidly

  7. When does the greatest risk for severe developmental disabilities occur? • The greatest risk for severe developmental disabilities occurs in the period between conception/implantation and birth (Decoufle et al., 2001) • Fewer than 10% of developmental disabilities occur during labor and delivery (Batshaw, 2002)

  8. Fertilization • When the mature ovum (egg) is released and is penetrated by a sperm (the sperm can remain viable in the tubes for 2-3 days; the egg can only be fertilized for 12-24 hrs)

  9. The Cell • Bodies are composed of over 100 trillion cells • Many types of cells • Each cell divided into two compartments: (1) central- the nucleus (2) outer area- the cytoplasm

  10. The Nucleus • Houses chromosomes (Greek for “colorful bodies”) • Contain the genetic code- DNA • DNA (1) deoxyribonucleic acid (2) contains physical and biochemical properties

  11. Chromosomes • Humans- 46 chromosomes • 46 (diploid number) are divided into 23 (haploid number) pairs of complementary chromosomes • In every chromosome pair, one comes from the mother/one comes from the father

  12. Conception: • Egg & sperm cells each contain only 23 chromosomes • Sperm contributes 23 + X or 23 + Y • Ovum contributes 23 + X • Germs cells fuse to produce fertilized egg = • XX (female) • XY (Y contributes “maleness”)

  13. Embryonic Development: • Day 1: Fertilization [2 weeks after LMP] • Sperm + Ovum = ZYGOTE • Day 2: Zygote divides; the group of multiplying cells is called the morula

  14. Day 4 & 5: Blastocyst forms (develops hollow cavity) The blastocyst lies free in the uterine cavity for about 2 days before attaching, or implanting, to the endometrium (inside wall of the uterus) • This marks the formal beginning of pregnancy, nearly 5-7 days after ovulation & fertilization

  15. What three types of cells does the embryonic stem differentiate into? • The embryonic stem cells differentiate into three types of cells: • Ectoderm • Mesoderm • Endoderm

  16. Embryonic development is divided into what two stages? • Embryonic- lasts from week 3 to week 8 after ovulation and fertilization, or week 5 to week 10 after the first day of the last menstrual period • Fetal- begins 8 weeks after ovulation and fertilization

  17. Embryonic Development [Cont.]: • Day 6: Early implantation • Day 7: Full attachment of embryo in uterus • In general, substances taken in wks 1 & 2 will either kill the embryo or enough cells recover to allow normal development • In general, no teratogenic effects

  18. Embryonic Development [Cont.]: • Day 15: 1st missed period • Day 16: 1st indications of neural groove • Week 3: Placenta formed; • Week 4: Primitive; neural tube forms • Ear & eyes, lips, palate, jaw • Upper limb buds

  19. Embryonic Development [Cont.]: • Week 5: • Heart tube forms • Lower limb buds • Week 6: • Oral + nasal cavities migrate • If abnormal = Cleft lip/palate • Tail present

  20. Embryonic Development [Cont.]: • Week 7: • Limbs bend • Fingers/toes webbed • Week 8: • Tail stub present

  21. Embryonic Development [Cont.]: • Week 8: Fetus • Head rounder • Tail gone • Cannot distinguish gender • Week 9: End of embryonic period • CR = 3.25 inches • Start of fetal development

  22. Fetal Development: • Essential structures present • 10th week: • Face appears child like • Genitalia distinguishable • Tremendous neurologic growth • Organ maturation

  23. Fetal Development [Cont.]: • 5th & 6th mo- fingernails form, skin thickens, movements purposeful; • End of 6th mo- weighs 2 lbs, 14 inches long • Gestation = 38 weeks (since conception) • Prematurity = < 35 weeks (3 weeks early) • Postmaturity = > 40 weeks (2 weeks late)

  24. Having a Baby • Approximately 266 days after conception, the process of labor begins. • The mothers immune system shuts down during the previous nine months but then decides to reject the baby.

  25. Labor • First stage- Mild contractions with may be confused with Braxton-Hicks which occur throughout the pregnancy; • Within hours the contractions become stronger, longer and more frequent, allowing the babies head to get into position for delivery- the vertex position;

  26. Labor- • the presence of regular uterine contractions leading to progressive effacement (thinning) • Dilation of the cervix • Expulsion of the fetus

  27. First Stage • Uterine contractions bring about effacement and progressive dilation of the cervix

  28. Second stage • Baby’s head pushes through the birth canal and appears at the vaginal opening; • Cervix becomes fully dilated;

  29. Third Stage • Usually lasts 10 to 15 minutes • The complete expulsion of birth of the newborn • Nose and mouth are bulb-suctioned to clear airway

  30. Umbilical cord is wrapped around the neck in ¼ of births (nuchal cord) • Cord is clamped and cut

  31. Other issues • Cesarean delivery- baby delivered through an incision in the abdomen and uterus; 5% in 1965 to 27.6% in 2003 (highest rate). • Dystocia- difficult labor • Protraction disorders • Cessation

  32. In 9 out of 10 cases, the result is a ruddy-cheeked, screaming, healthy baby.

More Related