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Pregnancy and Childbirth
Chapter 8
Understanding Fertility • Conception
– Involves the fertilization of a women’s egg by a man’s sperm – Each month a women’s ovaries release an egg
• Disintegrates after 24 hours if not fertilized – 3-4 days: The egg travels through the fallopian tubes – Millions of sperm but only a few reach the uterus – Sperm release an enzyme that softens egg
• Fraternal twins and identical twins
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Figure 8.1 Fertilization and early development of the embryo
Infertility • Female infertility
– One of two key causes
• Tubal blockage (40%)
• Failure to ovulate (40%) – Blocked fallopian tubes are
commonly caused by (PID)
» Chlamydia or gonorrhea
» Endometriosis
– Age, behavior, and exposure to toxic chemicals or radiation affect ovulation
4
Infertility
• Male infertility
– Accounts for about 20% of infertile couples
• Four main categories – Hypothlamic pituitary disease
– Congenital disorders
– Testicular disease
– Disorders of sperm transport
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Pregnancy • 3 periods of about 3 months (13 week trimesters) • Tests
– Home pregnancy tests – Human chorionic gonadotropin (HCG) – Can be used two weeks after fertilization
• Early signs and symptoms
– Missed menstrual period – Slight bleeding – Nausea – Breast tenderness – Increased urination – Sleepiness, fatigue and emotional upset
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© 2010 McGraw-Hill Companies. All Rights Reserved.
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Figure 8.2 Physiological changes during pregnancy
Continuing Changes in the Women’s Body
• Uterus size – During the first 3 months, the uterus enlarges to about
three times its nonpregnant size
– 4th month – large enough to make abdomen protrude
– 7th-8th month – pushes up into the rib cage
• Breast changes – 8th week – Breasts may tingle or throb
• Muscles and ligaments loosen
• Weight gain
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Changes During the Later Stages of Pregnancy
• Increased needs placed on the mother’s lungs, heart, and kidney
• Preliminary contractions (Braxton hicks contractions)
• Lightening
• Emotional responses to pregnancy
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Figure 8.3 The fetus during the third trimester of pregnancy
Fetal Development • First Trimester
– Blastocyst – Fourth day
• Arrives in uterus
– Embryo – End of second week
• Inner cells divide into three layers
• Endoderm– gut tube
• Mesoderm– muscle, bone, blood, kidneys, and sex glands
• Ectoderm– skin, hair, and nervous tissue
– All major body structures are formed between 2nd and 9th week
– 2nd Month – Fetus
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Fetal Development • Second Trimester
– Fetus grows to about 14 inches and 1.5 pounds
• Third Trimester
– Fetus gains protective fat layers, respiratory and digestive organs develop
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Figure 8.5 A cross-sectional view of the fetus in the uterus and an enlargement of the placenta
Diagnosing Fetal Abnormalities • Ultrasonography (Ultrasound)
– High frequency sound waves
• Amniocentesis – Fluid removal from the uterus
• Chorionic villus sampling – Removal of tiny section of chorionic villi
• Quadruple marker screen (QMS) – Maternal blood test – Analyzes four hormone levels and compares to appropriate
standards
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The Importance of Prenatal Care
• Regular medical checkups
• Blood tests
• Prenatal nutrition
• Avoiding drugs and other environmental hazards: – Teratogens
• 1st trimester
• Congenital malformations
– Alcohol
– Tobacco
– Caffeine
– Drugs
– STDs and other infections
15
The Importance of Prenatal Care
• Prenatal activity and exercise – Moderate exercise program
• 30 minutes most days
• Cardiovascular exercises
– Kegel Exercises
– Prenatal exercise classes
• Preparing for birth
16
Complications of Pregnancy and Pregnancy Loss
• Ectopic pregnancy
• Spontaneous abortion, or miscarriage
• Gestational diabetes
• Preterm labor
• Low-birth weight (LBW)
– Less than 5.5 pounds
• Infant mortality
– SIDS
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Labor and Delivery
• Entire process 2-36 hours
• First stage of labor – Average of 13 hours for a first birth
– Cervix is completely dilated (10 centimeters)
– Hormonal changes
– Contractions (30 seconds and occur every 15-20 minutes)
– Mucus plug is expelled and amniotic sac may rupture
– Transition: • Contractions may last 60-90 seconds and be 1-3
minutes apart 18
Childbirth • Second Stage of Labor
– Baby slowly pushed into birth canal
– Baby squeezes through pelvis
– Head is usually delivered first
– Umbilical cord is cut
• Third Stage of Labor – Delivery of the placenta
– Stage typically lasts 5-30 minutes
• Apgar score of the baby – Heart rate
– Respiration
– Color
– Reflexes
– Muscle tone
– Total score is between 0 and 10 19
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Figure 8.7 Birth: labor and delivery
Cesarean Deliveries
• 2006 about 31.1% of babies born in the U.S.
• Surgical removal of the baby
– Baby’s head too large
– Mother has a serious health condition
– Mother who is overweight or diabetes
– Difficult labor
– Fetal distress
– Dangerous infections
– 90% of cesarean mothers will have subsequent deliveries by cesarean
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Pain Relief During Labor and Delivery
• Childbirth preparation courses
– Breathing and relaxation techniques
– Lamaze, Bradley, or hypnosis
• Epidural
• Narcotics
– Fentanyl or demeral
– Provide less pain relief than a epidural
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Postpartum Period • 3 months following childbirth
• Critical family adjustment
• 6-8 weeks for the mother’s reproductive organs to return to pre-birth condition
• Breastfeeding
– About 74% of mothers breast-feed
– Lactation begins about 3 days post-childbirth
– Colostrum is produced prior to lactation
• Postpartum depression
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