Download CHAPTER 2: Development before Birth

CHAPTER 2: Development before Birth
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This chapter discusses the developmental process from conception through the
germinal, embryonic, and fetal periods. Issues related to prenatal care, hereditary and
genetic patterns, and genetic and chromosomal disorders are discussed as well as
environmental teratogens and maternal diseases and conditions.
Learning Objectives
After reading this chapter, you should be able to:

Understand the process of development from conception through the fetal period.

Recognize the importance of prenatal care.

Highlight characteristic developmental patterns at each stage of growth.

Describe typical and atypical hereditary and genetic patterns.

Understand the implications of a variety of maternal diseases, environmental factors,
and addictive behaviors for the developing infant.
Key Terms and Concepts
Amniotic sac consists of a pair of membranes that hold the embryo and then fetus
during pregnancy.
Autosomal dominant disorders relate to structural abnormalities in the individual.
Those who are heterozygous for an autosomal dominant disorder will be a carrier of and
be affected by the disorder.
Autosomal recessive disorders occur when a child receives an abnormal recessive
gene from both her father and her mother. The child would therefore be homozygous for
the autosomal recessive trait.
Chromosomes are very long continuous pieces (or molecules) of DNA that contain
many genes and other regulatory material.
Congenital refers to what is acquired at birth or during uterine development, as a result
of either hereditary or environmental influences.
Embryonic period starts from implantation and lasts about eight weeks. The rate of
growth is faster during the embryonic period than at any other time: all body tissues,
organs, and systems develop.
Environmental teratogens are substances in the environment that adversely affect the
development of the fetus, causing death, malformations, growth deficiency, or functional
deficits—for example, radiation, hyperthermia, mercury, and lead.
Fetal period lasts from the end of the second month of gestation until birth.
Genes are a unit of inheritance on chromosomes that consist of a long strand of DNA
and interact with other genes to influence physical development and behavior.
Genotype is the specific genetic genome or an individual’s DNA.
Germinal period is the process of a single ovum getting fertilized and then implanted in
a woman’s uterus.
Group B Streptococcus is a leading cause of sepsis and meningitis during the first
two months of neonatal life. In about half of the cases, the infant becomes ill in the first
week of life. The newborn may get sepsis, pneumonia, and meningitis. In other cases
the onset is later (a week to several months after birth) with meningitis more common.
Heterozygous is when two different alleles occupy the same place on a pair of genes.
Homozygous refers to two identical copies of a gene.
Hypertensive diseases are diseases characterized by chronically elevated blood
pressure (over about 140/90 or higher).
Phenotype is an individual’s physical appearance and constitution.
Placenta is formed out of the endometrium and supplies the embryo with oxygen and
nutrients and takes away wastes.
Single gene disorders are caused by a change or mutation in one gene.
STORCH refers to syphilis (S), toxoplasmosis (T), varicella and other congenital
infections (O), rubella (R), cytomegalovirus (C), and herpes simplex virus (H).
X-linked disorders are passed between generations by carrier mothers. They are
carried on the female sex chromosome (X), and typically involve mutations of genetic
information found on this chromosome.
Chapter Outline
Pregnancy
Prenatal Planning and Care
Heredity and Genetics: Just the Basics
Screening Techniques
Maternal Diseases, Disorders, and Illnesses
Exposure to Environmental Teratogens
Recommended Reading
Batshaw, M. L. (2007). Genetics and developmental disabilities. In M. L. Batshaw, L.
Pellegrino, N. J. Rosen (Eds.), Children with disabilities (6th ed., pp. 3–21).
Baltimore, MD: Paul H. Brookes.
Brown, J. E., & Satin, A. J. (2007). Having a baby: The birth process. In M. L. Batshaw,
L. Pellegrino, N. J. Rosen (Eds.), Children with disabilities (6th ed. pp. 35–45).
Baltimore, MD: Paul H. Brookes Publishing.
Davidson, P. W., & Myers, G. J. (2007). Environmental toxins. In M. L. Batshaw, L.
Pellegrino, N. J. Rosen (Eds.), Children with disabilities (6th ed., pp. 61–70).
Baltimore, MD: Paul H. Brookes.
Haffner, W. H. J. (2007). Development before birth. In M. L. Batshaw, L. Pellegrino, N.
J. Rosen (Eds.), Children with disabilities (6th ed., pp. 23–33). Baltimore, MD:
Paul H. Brookes.
Jensen, E. (2006). Enriching the brain: How to maximize every learner’s potential. San
Francisco, CA: Jossey-Bass.
Shore, R. (1997). Rethinking the brain: New insights into early development. New York:
Families and Work Institute.
Zero to Three. (2006). Ones, Twos, and Threes, 26(5). A major portion of this journal
focuses on the experience of having an only child, twins, and triplets and their
impact on parenting.
Relevant Web Sites
BabyCenter.com is the leading Web resource for new and expectant parents and
parents of children ages two to eight. The site provides extensive information needed
during pregnancy and in caring for a baby, toddler, or child. http://www.babycenter.com/
Human Genome Project, National Human Genome Research Institute (NHGRI) is
the official Web site of the Human Genome Project, which mapped the full human
genome. It is a great source for definitions and visual aids. The NHGRI is moving into
research aimed at improving human health and fighting disease. http://www.genome.gov
Kids Health is a project of the Nemours Foundation. Its mission is to translate advances
in health care to practical ways of improving health care for infants, children, and teens.
It has a narrated pregnancy calendar slide show. Take time to look at the other aspects
of the Web site. Note that information placed on this site is checked by a physician
before being put on the Web. http://www.kidshealth.org
National Center on Birth Defects and Developmental Disabilities provides
information about birth defects and their implications. http://www.cdc.gov/ncbddd/
National Institute on Drug Abuse (NIDA), the official government site, is part of the
National Institutes of Health (NIH). Anyone interested in the relationship between drug
abuse and HIV/AIDS can find useful information on this site. http://hiv.drugabuse.gov/
Parenting iVillage, although a commercial site, provides a great slide show that
documents fetal development from six weeks to birth. This is free, and the photos are
furnished by GE Healthcare. http://parenting.ivillage.com
Pregnancy.org provides a large online forum for parents who want to find out or share
information on pregnancy, childbirth, and parenting. http://www.pregnancy.org/
U.S. Food and Drug Administration (FDA) lists the FDA regulations on medications,
medical devices, food safety, and other useful links that are related to a safe and healthy
pregnancy. Navigate to its page on pregnancy. http://www.fda.gov/