Chapter 4: Prenatal Development and Birth

1. Chapter 4: Prenatal Development and Birth

2. PrenatalDevelopment

3. Prenatal development is divided into 3 periods and lasts approximately 266 days: • Germinal period: first 2 weeks after conception, zygote created. • Embryonic period: occurs from 2 to 8 weeks after conception. • Fetal period: begins 2 months after conception and lasts until birth.

4. Significant Development in the Germinal Period ©2008 The McGraw-Hill Companies, Inc. All rights reserved.

5. The Placenta and the Umbilical Cord ©2008 The McGraw-Hill Companies, Inc. All rights reserved.

6. 19 inches long, weighs 6 pounds About 16.5–18 inches long, weighs 4 to 5 pounds 36 to 38 weeks Conception to 4 wks About 14-17 inches long, weighs 2.5 to 3 pounds To 32 wks Less than 1/10th of an inch long To 28 wks To 8 weeks To 24 wks About 11-14 inches long, weighs 1 to 1.5 pounds Less than 1 inch long To 20 wks To 16 weeks To 12 weeks About 10-12 inches long, weighs 1/2 to 1 pound About 3 inches long, weighs about 1 ounce About 5.5 inches long, weighs about 4 ounces First trimester begins Third trimester begins The Three Trimesters of Prenatal Development See Figure 4.3 in textbook for more details Second trimester begins Fig. 4.3 ©2008 The McGraw-Hill Companies, Inc. All rights reserved.

7. Prenatal Development

8. Issue of Abortion • Beliefs and words seasoned with love • If strongly opposed, then what alternatives are you offering.

9. Teratogen: any agent that causes birth defects: • Drugs (prescription, nonprescription). • Alcohol, tobacco. • Environmental pollutants. • Infectious diseases. • Nutritional deficiencies. • Maternal stress. • Advanced age of a parent. • Severity of damage to the unborn depends on: • Dose. • Time of exposure. • Genetic susceptibility.

10. Teratogens and Timing of Their Effects on Prenatal Development Zygote Embryonic period (wks) Fetal Period (wks) Central nervous system Most serious damage from teratogens in first 2-8 wks Heart Arms Eyes Legs Ears Teeth Palate Period of susceptibility to structural defects External genitalia Period of susceptibility to functional defects Fig. 4.4 ©2008 The McGraw-Hill Companies, Inc. All rights reserved.

11. Fetal alcohol syndrome: abnormalities in newborn due to mother’s heavy use of alcohol in pregnancy. • Abnormalities include: • Facial deformities. • Defective limbs, face, heart. • Most have below-average intelligence. • Some are mentally retarded.

12. Moderate drinkers during pregnancy had babies who were less attentive and alert even at 4 years of age. • Maternal smoking can cause : • respiratory problems. • SIDS. • ADHD. • low birth weight.

13. Illegal drugs that harm during pregnancy: • Cocaine. • Marijuana. • Heroin. • Incompatible blood types (Rh factor). • Environmental hazards: exposure to radiation or chemicals. • STDs, HIV infection, AIDS.

14. Fetal Alcohol Syndrome

15. Other Parental Factors • Maternal factors: • Maternal diet and nutrition. • Emotional states and stress. • Maternal age. • Paternal factors: • Paternal exposure to teratogens including smoking. • Paternal age.

16. Percentage of U.S. Women Using Timely Prenatal Care: 1990 to 2004 100 1990 90 2004 80 70 60 50 Percentage 40 30 20 10 0 Non-Latino White women African American women Latino women Fig. 4.6 ©2008 The McGraw-Hill Companies, Inc. All rights reserved.

17. Preparation for Labor & Delivery • Classes • Attitude • Plain for pain management • Natural vs Drugs

18. Birth

19. Three stages of birth: • Uterine contractions begin at 15 to 20 minutes apart and last 1 minute; this stage lasts an average of 12 to 24 hours. • Baby’s head begins to move through dilated cervix opening; this stage lasts 1.5 hour on average. • Afterbirth: umbilical cord, placenta, and other membranes are detached and expelled.

20. Birth complications include anoxia: insufficient oxygen to brain when delivery lasts too long. • Childbirth setting: • Hospital delivery room. • Home delivery with midwife. • Doula – provides continuous physical, emotional, and educational support for mother before, during, and after childbirth.

21. Methods of childbirth—key choices involve use of medication and when to have a cesarean delivery. • Drugs used: • Analgesia – pain relief. • Anesthesia – blocks sensation. • Oxytocics – synthetic hormones to stimulate contractions. • Natural childbirth—aims to reduce pain by decreasing fear and breathing techniques (Grantley Dick-Read). • Prepared childbirth—Lamaze—special breathing and education about anatomy and physiology.

22. Other non-medicated techniques to reduce pain • Waterbirth • Massage • Acupuncture • Hypnosis • Music therapy

23. Cesarean Delivery: • Needs to be used if baby is in breech position or other complications. • Many today are choosing cesarean delivery. • Women in need of cesarean delivery are more quickly identified. • Doctors may order cesarean out of caution, and to avoid lawsuit if there is a possibility of maternal or fetal distress. • Today, 29.1 percent of all births are cesarean.

24. Measuring neonatal health and responsiveness: • Apgar Scale, used 1–5 minutes after birth: • evaluate heart rate, body color, muscle tone, respiratory effort, and reflex irritability. • Brazelton Neonatal Behavioral Assessment Scale performed within 24–36 hours after birth: • 27 items are organized into 4 categories – physiological, motoric, state, and interaction. • Assesses newborn’s neurological development, reflexes, and reactions to people.

25. The Apgar Scale Fig. 4.7 ©2008 The McGraw-Hill Companies, Inc. All rights reserved.

26. Causes of low birthweight: • Preterm babies. • Small-for-date babies. • Problems in developing countries. • Possible consequences of low birthweight: • Brain injuries. • Lung and liver diseases. • Learning disabilities. • ADHD. • Lower levels in reading and math achievement. • Deficits are evident in adulthood.

27. About 50% of low-birthweight children are enrolled in special education programs. • Low birthweight is linked to asthma. • Some defects can be improved with: • Early speech therapy. • Intensive enrichment programs. • Kangaroo care and massage therapy.

28. Care for preterm infants: • Kangaroo care—holding preterm infant so there is always skin-to-skin contact. • Massage therapy—Tiffany Field’s research.

29. Weight Gain Comparison of Premature Infants Who Were Massaged with Those Not Massaged Premature infants who were massaged 3 lb. 7 oz 3 lb. 5 oz Premature infants who were not massaged 3 lb. 3 oz 3 lb. 1 oz Infant weight 2 lb. 15 oz 0 2 4 6 8 10 12 14 Age (days) Fig. 4.8 ©2008 The McGraw-Hill Companies, Inc. All rights reserved.

30. The Postpartum Period

31. Postpartum period lasts about 6 weeks after childbirth when woman adjusts physically and psychologically back to the prepregnant state: • Influenced by preceding conditions and experiences. • Mother learns to care for the baby, feel good about herself, and those close to her. • Physical: hormone changes, weight loss, return to menstruation, loss of energy or fatigue. • Psychological: feelings of depression, anxiety, coping in new role, excessive worrying.

32. 70% 20% 10% Percentage of U.S. Women Who Experience Postpartum Blues and Postpartum Depression Postpartum blues: symptoms appear 2 to 3 days after delivery and subside within 1 to 2 weeks No symptoms Postpartum depression: symptoms linger for weeks or months and interfere with daily functioning Fig. 4.9 ©2008 The McGraw-Hill Companies, Inc. All rights reserved.

33. A Father’s Adjustment: • Generally ignored, but fathers go through considerable adjustment. • Some feel baby has replaced them in terms of mother’s affection. • Fathers should actively care for the baby. • Parents should set aside time to be together.

34. Bonding (formation of emotional attachment) between infant and mother: • Usually occurs in period shortly after birth. • Critical component in child’s development. • Isolation of premature baby and use of drugs in birth process may harm bonding process. • Some experts advocate a rooming-in arrangement while mother and child are in the hospital.