Reproduction

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Reproduction Birthing

• When a sperm fertilizes an ovum to form a zygote
  within the fallopian tube, 23 chromosomes from
  both the sperm and the egg combine to form a
  total of 46.
• The DNA in these chromosomes establishes the
  genetic instructions for developing the new
  organism.

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Pre-pregnancy

• To prevent birth defects, avoid teratogens before
  and during pregnancy
• Drugs, other chemicals, and radiation
• Have blood tests for
• antibodies against rubella
• HIV infection
• Avoid cat litter boxes
• Genetic counseling can identify inherited risks

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Importance of Diet

• Folic acid can prevent neural tube defects
• Stop smoking, drinking alcohol, and taking drugs
  of any kind
• Avoid excessive weight gain
• If there are concerns, diagnostic tests are
  available
• Chorionic villus sampling
• Ultrasound
• Amniocentesis

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Pregnancy Signs

• Missed period
• There may be slight bleeding one week before the
  normal time of menses
• Sore and swollen breasts
• Nausea and mood changes
• A home pregnancy test is generally valid and
  reliable when used correctly

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Fetal Development
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Fertilization Fetal Development

• Sperm penetrates the zona pellucida of the ovum
  at conception
• Fertilization of an ovum forms a zygote
• Ovum and sperm each contribute 23 pairs of
  chromosomes containing DNA
• Twins or multiples result under two conditions
• More than one ova fertilized by more than one
  sperm
• fraternal, or dizygotic, twins
• Fertilized ovum which splits
• identical, or monozygotic, twins

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Multiple Births

• The rate of multiple births has been increasing
  largely because of increased use of fertility
  drugs. Multiple births are associated with
  greater risks of birth defects and premature
  birth.
• Fraternal (dizygotic) twins result from the
  fertilization of two separate ova by two sperm.
  Identical (monozygotic) twins are formed when a
  single zygote divides into two cells that
  separate and develop into individual embryos.
  Because they have exactly the same chromosomes,
  these twins are identical in appearance.
• Some scientists believe that a third type,
  half-identical twins, exists as well. These are
  said to be formed by the fertilization of two
  eggs that split from a single egg cell prior to
  fertilization by two separate sperm cells.
  Therefore, the two offspring each have half of
  their chromosomes identical.

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• The zygote divides into an increasing numbers of
  cells, eventually forming a spherical blastocyst.
  A few days after fertilization, the blastocyst
  implants itself in the inner lining (endometrium)
  of the uterus, where embryonic and fetal
  development continues.

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• From the moment of conception to the time a baby
  is born, remarkable changes occur. An entire
  human body develops, with internal systems that
  can function to support life and enable the fetus
  to move and react to stimuli.

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• The embryo forms several extraembryonic membranes
  for its protection and nourishment. The amnion is
  a fluid-filled sac that is used to keep the
  embryo moist and cushioned. The yolk sac and
  allantois become partly incorporated into the
  umbilical cord which connects the fetus with the
  placenta. The chorion is the outside membrane
  that helps form the placenta, through which the
  blood systems of the fetus and the mother come
  close enough to permit exchange (by diffusion) of
  nutrients and wastes.

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Fetal Assessment

• Several methods are used to diagnose potential
  medical problems in a fetus.
• Amniocentesis withdraws fetal cells from the
  amniotic sac so that possible chromosome
  abnormalities may be discovered.
• Chorionic villi sampling (CVS) also examines
  chromosomes but may be used as early as the
  eighth week in the pregnancy.
• Ultrasound pictures, or sonograms, are an
  alternative to X-rays for examining the features
  of the developing fetus. Ultrasound is not
  recommended for routine use.
• Embryoscopy and fetoscopy allow for visual
  examination of embryos and fetuses. Fetal surgery
  is a developing technology that can be used to
  treat some medical difficulties.

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Stages of Pregnancy
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Stages of Pregnancy

• 38 weeks
• Major changes take place for the mother and
  embryo/fetus
• Three trimesters
• Embryo develops in the first trimester
• Fetus develops the last two trimesters

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The Birth Process

• False labor consists of irregular contractions
  that do not increase in strength
• Three stages of true labor
• Cervical dilation
• Fetal delivery
• Placental delivery

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The Birth Process

• Normally the baby is delivered head first
• Breech (feet, buttocks, or shoulder first)
• A cesarean section is needed in some situations
• Episiotomy - cut made by physician in tissues
  surrounding vagina to prevent tearing

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• The birth process begins with contractions of the
  uterus, or labor. Gradually, the baby is moved
  through the birth canal and is born. The
  placenta, umbilical cord, and fetal membranes
  follow as the afterbirth.

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Circumcision

• The foreskin is removed from the penis of the
  male infant
• Has potential medical benefits and carries small
  risks

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Postpartum Recovery

• 6-week period after childbirth during which
  mothers body returns to pre-pregnancy status
• Mild depression may result from physical and
  mental stresses of childbirth and hormonal changes

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Pregnancy, Complications Sexuality

• Pregnancy-induced hypertension is a complication
  of pregnancy that involves a rise in the mothers
  blood pressure and a buildup of fluids in her
  body, sometimes with life-threatening
  consequences.
• There are many approaches to birthing, including
  those that emphasize full awareness and
  participation on the mothers part such as the
  Lamaze method. Many women use some pain-relieving
  medications or anesthesia during labor and
  delivery.
• Unless there is a problem with a pregnancy, there
  is no need to avoid sexual contact during
  pregnancy. To ensure healthy pregnancies, it is
  best that they be spaced at least nine months
  apart.

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Issues in Reproduction Pregnancy
Surrogate Motherhood
Ova Sperm Donation
Choosing Sex of the Fetus
Cloning
Prematurity
Breastfeeding
Birthing Alternatives
Episiotomy
Pregnancy-Induced Hypertension
Pain Relief During Birth
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Fertility and Infertility
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Fertility vs. Infertility

• Fertility is the ability to conceive a child
• Infertility is the inability to conceive a child
  after one year of unprotected sex
• Low sperm count
• High percentage of abnormally shaped sperm
• Scarring in the female genital tract
• Structural defects of the uterus
• Hormonal imbalances

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Treatments for Infertility

• Lifestyle changes
• Medication
• Hormone therapy
• Surgical procedures
• In vitro fertilization and assisted reproductive
  technology

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Issues Related to Pregnancy

• Surrogate motherhood, or gestational surrogacy,
  is a controversial approach in which one woman
  agrees, for a fee, to carry a pregnancy and give
  the baby to another couple. Sometimes the
  surrogate is impregnated by the sperm of a man
  whose partner cannot become pregnant, and
  sometimes IVF is used to transfer an embryo
  produced from the egg and sperm of one couple
  into the surrogates uterus.
• Cloning involves the creation of genetically
  identical organisms. New techniques have allowed
  the separation of early embryonic cells and thus
  the creation of genetic duplicates of an early
  human embryo. The prospect of human cloning
  raises ethical, social, and legal complications,
  and clones may be at risk for eventual defects.

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Reproductive Fetal Technology

• Genetic Engineering
• Gene Therapy
• Artificial Insemination
• In Vitro Fertilization
• Zygote intrafallopian transfer
• Preimplantation genetic diagnosis

• Gamete Intrafallopian Transfer
• Intracytoplasmic Sperm Injection
• Computerized sperm selection
• Microscopic epididymal sperm aspiration

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Infertility Technology

• Advances in reproductive technology are
  revolutionizing the processes of conception and
  gestation. Genetic engineering and gene therapy
  are opening the possibilities of early diagnosis
  and treatment of human genetic disorders,
  although they have yet to prove their worth.
• Gametes (sperm and eggs) and embryos may now be
  frozen and kept for long periods for later use in
  various reproductive technologies. Concerns are
  growing about the ethics involved with frozen
  embryos and the possible link of freezing with
  later problems of pregnancy and birth defects.
• Gamete intrafallopian transfer (GIFT) is a
  process in which sperm and eggs are placed
  directly into the fallopian tubes.
• Intracytoplasmic sperm injection (ICSI),
  computerized sperm selection, and the
  transplantation of sperm-producing cells to
  infertile males all offer hope of increasing the
  likelihood of having viable sperm for
  reproduction.
• Infertility can have many causes and often
  creates stress for couples who are anxious to
  have children. New reproductive technologies are
  offering more hope for infertile couples.

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In Vitro Fertilization

• In vitro fertilization (IVF) allows for
  fertilization outside a womans body, with the
  developing embryo then being implanted into the
  uterus afterward.
• The success rate of IVF is still limited, and its
  associated costs are high.
• Immature oocyte collection permits immature eggs
  to be obtained, after which they are matured by
  cell-culturing methods. This technique could
  reduce the costs of IVF significantly.

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SUMMARY

• Reproductive capabilities are important
• Sexual responses among men and women are variable
• Pregnant women or those planning a pregnancy
  should consult with their physician
• There are methods to assist with fertility
• Many contraceptive methods are available
• Hormonal and physical changes occur throughout
  the lifespan