Infants, Children, and Adolescents Eighth Edition Chapter 3 Prenatal Development

Learning Objectives (1 of 2) 3.1 How has decision making about childbearing changed over the past half century, and what are the consequences for child rearing and child development? 3.2 List the three phases of prenatal development, and describe the major milestones of each. 3.3 What are teratogens, and what factors influence their impact? 3.4 List agents known to be or suspected of being teratogens, and discuss evidence supporting their harmful impact.

Learning Objectives (2 of 2) 3.5 Describe the impact of other maternal factors on prenatal development. 3.6 Why is early and regular health care vital during the prenatal period? 3.7 What factors contribute to preparation for parenthood during the prenatal period?

Why Have Children? In Western nations, having children is a matter of individual choice. 90% of U.S. adults have or plan to have children, depending on: Financial circumstances Career goals Values Health conditions

Why Have Children? (continued) Advantages: Personal fulfillment Being a responsible and mature adult Caregiving and support in old age Continuing the family name Strengthening couple relationship

Why Have Children? (continued) Disadvantages: Responsibility for child’s well-being Role overload Financial strain Loss of privacy

How Large a Family? Average number of children has declined in Western nations since 1960 More effective birth control Fewer children more compatible with women’s careers Divorce Low-SES mothers tend to have more children

American Mothers Getting Older Advantages: More emotionally mature Financial stability Disadvantages: Declining reproductive capacity (female and male) Increased risk of chromosomal and genetic disorders

American Women Bearing Children at Older Ages Figure 3.1: First births to American women of different ages in 1970 and 2008 Figure 3.1 (Based on U.S. Census Bureau, 2014b.)

Conception and Implantation Figure 3.2: Female reproductive organs, showing fertilization, early cell duplication, and implantation Figure 3.2 (From Before We Are Born, 6th ed., by K. L. Moore and T. V. N. Persaud, p. 87. Copyright © 2003, reprinted with permission from Elsevier, Inc.)

Periods of Prenatal Development Germinal Embryonic Fetal

Germinal Period Weeks 1–2 Implantation of the blastocyst Development of the Amnion Chorion Placenta Umbilical cord

The Placenta and Umbilical Cord Figure 3.3: cross-section of the uterus, showing detail of the placenta Figure 3.3 (From Before We Are Born, 6th ed., by K. L. Moore and T. V. N. Persaud, p. 95. Copyright © 2003, reprinted with permission from Elsevier, Inc.)

Embryonic Period Weeks 3–8 Central nervous system, internal organs, muscles, and skeleton begin to form. Heart begins pumping blood. Liver and spleen begin producing blood cells. Neurons develop rapidly. External features also form: eyes, ears, nose, limbs. Testes in male begin producing testosterone

Fetal Period Week 9 to the end of pregnancy First trimester: Organs, muscles, and nervous system organize. External genitals are well-formed. Second trimester: Mother can feel movements. Neurons form synapses at a rapid pace. Sensitivity to sound and light emerges.

Fetal Period (continued) Third trimester: Fetus reaches age of viability (between 22 and 26 weeks). Rapid gain in neural connectivity and organization continue. Responsiveness to external stimulation increases. Extensive body growth occurs.

Prenatal Environment and Later Health Low Birth Weight Greater chance of Heart Disease Stroke Diabetes High Birth Weight Breast cancer Prostate and other cancers

Prenatal Environmental Influences: Teratogens Any environmental agent that causes damage during the prenatal period Effects depend on: Dose Heredity Other negative influences Age

Teratogens Drugs Tobacco Alcohol Radiation Pollution Prescription Nonprescription Illegal Tobacco Alcohol Radiation Pollution Infectious disease

Drugs Prescription and nonprescription Isotretinoin: eye, ear, skull, brain, heart, and immune system abnormalities Aspirin: possible low birth weight, infant death, poor motor development, lower intelligence Caffeine: low birth weight Antidepressants: premature delivery, birth complications, high blood pressure

Drugs (continued) Illegal drugs Cocaine, heroin, and methadone are all linked to a variety of severe problems. Marijuana is associated with poor academic achievement, impulsivity, depression. Lasting findings, however, are not well established.

Tobacco 11% of U.S. women smoke while pregnant. Can cause: Low birth weight Miscarriage Prematurity Cleft lip and palate Abnormal blood vessels Infant death Asthma and cancer later in childhood

Fetal Alcohol Spectrum Disorder: Criteria for Diagnosis DIAGNOSTIC CATEGORY Criteria FAS p-FAS ARND Slow physical growth Yes No Facial abnormalities: Short eyelid openings Thin upper lip Smooth or flattened philtrum All three are present Two of the three are present None are present Brain injury Impairment in a minimum of three areas of functioning Table 3.3 Source: Mattson, Crocker, & Nguyen, 2012.

The Effects of Environmental Pollution More than 75,000 chemicals are in common use in the United States. Many babies are “born polluted” Diverse impairments in physical and mental development Increased chances of life-threatening diseases and later health problems

Infectious Disease Viruses Bacteria and Parasites Rubella Chickenpox HIV and AIDS Various herpes viruses Bacteria and Parasites Toxoplasmosis Chlamydia and syphilis Tuberculosis

Maternal Factors in Prenatal Development Exercise Nutrition Emotional stress Rh blood factor Maternal age Previous births

The Effects of Emotional Stress on the Developing Fetus Stress hormones cross the placenta, causing a dramatic rise in fetal heart rate and activity. Maternal emotional stress predicts anxiety, short attention span, anger, aggression, and overactivity among young children. Stress-related prenatal complications can be greatly reduced when mothers receive support from family members and friends.

The Nurse–Family Partnership Voluntary home visiting program for low-income, first-time mothers Children having experienced the program show: Higher language and intelligence scores Fewer behavior problems Mothers in the programs experience: Fewer subsequent births, greater birth spacing More contact with child’s father More stable intimate relationships Less welfare dependence

Prenatal/Birth Complications Increase with Maternal Age Figure 3.6: Relationship of maternal age to prenatal and birth complications Figure 3.6 (Based on Salihu et al., 2003.)

Iron Deficiency and Memory Impairments in Infants of Diabetic Mothers Throughout pregnancy, mother’s volatile glucose levels can cause birth defects or abnormal fetal growth. The fetus’s reaction to this extra glucose results in iron deficiency, which harms brain cell growth. Resulting memory problems continue into the preschool years.

Expectant Mothers with Late or No Prenatal Care Figure 3.7: Expectant mothers in the United States with late (after the first trimester) or no prenatal care Figure 3.7 (Based on Child Trends, 2014b.)

Reasons Women Delay Prenatal Care Financial hardship Situational barriers Personal barriers Many are reluctant to disclose high-risk behaviors

Culturally Sensitive Prenatal Care Promotes Healthy Pregnancies Low-SES ethnic minority women often reported depersonalizing prenatal care. Group prenatal care offers a sensitive alternative group discussions about health issues in native language led to more health-promoting behaviors and reduced low birth weight and prematurity

Preparing for Parenthood Expectant parents get to know the baby as an individual. look for models of effective parenthood. adjust their relationship as a couple.

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