Conception, Pregnancy, and Childbirth

1
Chapter 12

• Conception, Pregnancy, and Childbirth

2
The Fertilization Process

• Ovum released from ovary, drifts to fallopian
  tube
• Oocyte viable 12 - 24 hours after ovulation
• Sperm viable 12 - 48 hours
• Capacitation takes 6-8 hours
• biochemical changes in sperm cell release
  enzymes that allows it to penetrate eggs outer
  membranes

3
Fertilization Process

• A single sperm is inside the oocyte cytoplasm
• An electrical reaction prevents any other sperm
  from entering
• Oocyte swells
• Detaches sperm that cling to outer layer
• Sperm and ovum nuclei release chromosomes
• Chromosomes divide to form the diploid zygote
  containing 23 pairs of chromosomes
• Fertilization is now complete

4
Development of the Conceptus

• Zygote undergoes cell divisions
• Becomes a blastocyst of 100 cells after 4-5 days
• Blastocyst implants in uterine lining on 6th or
  7th day
• Blastocyst becomes embryo after implantation in
  uterus
• Embryo is called a fetus after 8th week

5
Pregnancy Detection

• Test for human chorionic gonadotropin (HCG)
• Blood analysis
• Home pregnancy tests
• Early physical signs
• Changes in cervix occur about 4 weeks after a
  missed period
• Hegars sign
• Labia change color, gaining purple hue

6
Changes in Women During Pregnancy

• Vary according to womans personality, feelings,
  and circumstances
• Changes in relationships
• Physical and emotional changes during each
  trimester
• Three trimesterseach 3 months long
• First trimester may include nausea, vomiting,
  fatigue

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Complications of Pregnancy and Dangers to the
Fetus

• Effects of teratogens
• Substances that cause defects in embryonic and
  fetal development
• Infectious diseases
• German Measles (rubella)
• Group B streptococcus

8
Complications of Pregnancy and Dangers to the
Fetus

• Sexually transmitted infections
• Can be transmitted from pregnant woman to fetus,
  newborn, or infant

• Chlamydia
• Gonorrhea
• Hepatitis B
• HIV
• Syphilis
• Genital herpes

9
Complications of Pregnancy and Dangers to the
Fetus

• Pregnancy after age 35
• Is more common as women wait to have children
• Increased likelihood of chromosomal variation
• Risk increases with increasing maternal age

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Complications in Pregnancy

• Ectopic pregnancy
• Pregnancy-induced hypertension
• Premature births
• Delayed labor

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Diagnosing Abnormalities of the Fetus

• Ultrasound
• Amniocentesis
• Chorionic villus sampling (CVS)
• Alpha-fetoprotein (AFP) screening

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Ultrasound

• High frequency sound waves determine size and
  position of fetus
• Sonogrampicture
• Estimates fetal age, guides during amniocentesis,
  checks for physical birth defects, evaluates
  complications during pregnancy

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Amniocentesis

• Amniotic fluid is withdrawn with needle inserted
  through abdominal wall
• Detects fetal abnormalities Downs syndrome,
  Turners syndrome, cystic fibrosis, spina bifida,
  sex and age
• 0.5-2 chance of fetal death

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Chorionic Villus Sampling (CVS)

• Thin catheter inserted through abdomen or cervix
  into uterus and some chorionic villi are sucked
  into tube
• Detects fetal abnormalities
• Performed 9-11 weeks

15
Alpha-fetoprotein Screening

• Test run on mothers blood
• After 16 weeks of pregnancy
• Detects defects of spine, spinal cord, skull and
  brain

16
Pregnancy Loss

• Early pregnancy loss
• Miscarriage
• Infant mortality
• Coping with loss

17
Infertility

• The inability to conceive a child after a year of
  unprotected intercourse or the inability to carry
  a child to term
• Fertility issues are equally distributed among
  men and women
• 1 of children in U.S. are the product of
  assisted fertility

18
Female Infertility

• Physical causes
• Pelvic Inflammatory Disease, an infection of the
  fallopian tubes or uterus
• Approximately 20
• Hormonal psychological causes
• Hormone release may be atypical
• Stress, anxiety, allergy
• Approximately 20
• Environmental factors

19
Male Infertility

• Low sperm count
• Decrease of sperm motility
• Misshapen sperm
• Sperm duct blockage
• Ejaculatory difficulties
• Environmental factors
• Mens fertility begins dwindling after age 27

20
Infertility Treatment

• Enhancing fertility
• Selective timing of sexual activity
• Man wears boxer underwear
• Woman lies with her back elevated following
  internal ejaculation

21
Medical Intervention

• Fertility medications
• Surgery
• Artificial insemination

22
Assisted Reproductive Technology

• In vitro fertilization - IVF
• Gamete intrafallopian transfer GIFT
• Zygote intrafallopian transfer ZIFT
• Surrogate motherhood
• Cloning
• Sex selection

23
Giving Birth Labor and Delivery

• Relaxin released by the placenta
• Braxton Hick contractions

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Labor Stages

• Stage 1
• Effacement thinning of cervix
• Dilation opening up of cervix
• Mucus plug is expelled
• Amniotic sac ruptures
• Contractions are regular and progressive
• Transition

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Labor and Delivery

• Stage 2
• Begins when babys head moves into birth canal
• Ends when baby is born
• Vernix waxy substance which may cover baby
• Stage 3
• Afterbirth placenta is expelled

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Following birth

• Neonate
• Apgar score
• Lochia
• Joy

27
Choices in Childbirth

• Hospital birth
• Cesarean section
• Prepared childbirth
• Episiotomy
• Birthing rooms and centers
• Home birth
• Midwifery

28
Breast Feeding

• Colostrum
• Benefits
• Bonding
• Immune system of baby
• HIV

29
Becoming a Parent

• Postpartum period
• Postpartum depression
• Postpartum psychosis
• Family Medical Leave Act

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Summary

• Fertilization and fetal development
• Being pregnant
• Infertility
• Giving birth
• Becoming a parent