Chapter 4 PowerPoint






Germinal period – creation of the zygote – one week after conception – 100/150 cells.

Embryonic period – support systems for cells – 2/8 weeks after conception.

Fetal period – begins at two months, lasts for seven – period of organ growth.




Exploring Teratology – agents that cause birth defects and their study

Prescription and Nonprescription Drugs – Several drugs used by the mother that have negative effects on the embryos and fetuses.

Psychoactive drugs are used to alter states of consciousness, modify perceptions, and change moods. The effects of alcohol, nicotine, and illegal drugs on the fetus are well-documented.

Incompatibility of blood types where the fetus’s blood is RH positive ad the mother’s is RH negative cause antibodies to attack the fetus, resulting in serious, often life-threatening damage.

Environmental hazards of the modern world can cause chromosomal abnormalities. Exposure to toxins, radiation, pollutants, and excess heat can all contribute to a negative impact on the fetus.

Other maternal factors such as infectious diseases (Rubella, Syphilis,

AIDS), all have varying degrees of impact on the fetus. Also considered are emotional stress, age, and nutrition of the mother.

Paternal factors can impact fetal growth such as pesticides at the workplace, smoking and diet.

Positive prenatal development includes activities and behavior by the parents that demonstrate a caring concern for the growth of the fetus and attempting to control the factors that can be manipulated.


Confirming the pregnancy – Fetal life begins with the fertilization of the ovum, with pregnancy length calculated from the first day of the woman’s last menstrual period.

The Three Trimesters: First – initial three months when prenatal organ systems are formed – physical and emotional adjustment for the mother; Second – middle months, continued growth of fetus, mother’s physical adjustment to the change; Third – uterus expands, some leg problems with blood flow, physically exhausting.

The Expectant mother’s nutrition, weight gain, and exercise are monitored for her health and that of her baby. Weight gain should be between 2.2 pounds per month and 6.6 (excessive). Appropriate levels of vitamins and adequate exercise all contribute to a healthy balance.

Culture and Prenatal care are also considerations that affect the fetus. Industrial countries generally have lower numbers of lowbirthweight babies, with the United States at 7 percent; however, this is higher among African-American infants.

Cultural beliefs also impact prenatal care

– In India midwives play a large role in the birthing process. Other cultures rely on ancient medicinal practices and/or strong familial cooperation.