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

2

3

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

5

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

6

© 2010 McGraw-Hill Companies. All Rights Reserved.

7

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

8

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

9

10

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

11

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

12

13

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

14

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

17

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

20

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

21

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

22

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

23