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

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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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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

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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

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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

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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 1019

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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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