Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 4 Pregnancy and Prenatal Development

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4-2 Table Early Signs and Symptoms of Pregnancy

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4-3 Prenatal Development  Cephalocaudal principle: Development proceeds in a head-to-tail direction.  Upper parts of the body develop before lower parts of the trunk.  Proximodistal principle: Development proceeds from within to without.  Parts of the body near the center develop before the extremities.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4-4 Prenatal Development  Gestation: Period of development between conception and birth.  Gestational age: Age of an unborn baby, usually dated from the first day of an expectant mother’s last menstrual cycle.  Takes place in three stages:  Germinal, embryonic, and fetal

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4-5 Germinal Stage  First 2 weeks of prenatal development  Characterized by:  Rapid cell division  Increasing complexity and differentiation  Implantation in the wall of the uterus  Implantation: Attachment of the blastocyst to the uterine wall, occurring at between day 6 and 10.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4-6 Figure Early Development of a Human Embryo

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4-7 Embryonic Stage  Characterized by rapid growth and development of major body systems and organs.  From about 2 to 8 weeks  Organogenesis: Process in which the organs and major body systems develop rapidly.  Respiratory, digestive, and nervous  Severely defective embryos usually do not survive beyond the first trimester of pregnancy.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4-8 Embryonic Stage  Spontaneous abortion: Natural expulsion from the uterus of a embryo that cannot survive outside the womb.  Factors that may cause miscarriages  Abnormal pregnancies  Chromosomal abnormalities  Smoking  Drinking alcohol, and drug use

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4-9 Figure The Developing Embryo

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Figure Organogenesis

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Fetal Stage  Final stage of prenatal development, 8 weeks to birth.  Characterized by increased differentiation of body parts and greatly enlarged body size.  Fetus adds a layer of fat in preparation for birth.  Ultrasound: Prenatal medical procedure using high- frequency sound waves to detect the outline of a fetus and its movements.  Determines if a pregnancy is progressing normally.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Maternal Factors  Prenatal environment is the mother’s body.  Everything that affects the mother’s well-being may alter her unborn child’s environment and influence its growth and health.  Teratogen: Environmental agent that can interfere with normal prenatal development and cause developmental abnormalities.  Virus, a drug, or radiation

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Nutrition and Maternal Weight  Pregnant women typically need 300 to 500 additional calories a day, including extra protein.  Gaining too much weight leads to the risk of having a large baby that needs to be delivered by induced labor or cesarean section.  Critical to include folic acid or folate in a pregnant woman’s diet.  Vitamin D deficiency may increase the risk of a child’s developing multiple sclerosis later in life.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Physical Activity and Strenuous Work  Moderate exercise does not seem to endanger the fetuses of healthy women.  Pregnant women should not push themselves and raise their heart rate above 150.  Regular exercise prevents constipation and improves respiration, circulation, muscle tone, and skin elasticity.  Greater risk of premature birth  Strenuous working conditions, occupational fatigue, and long working hours

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Drug Intake  Medical drugs - No medication should be prescribed for a pregnant or breast-feeding woman unless it is essential for her health or her child’s.  Alcohol  Fetal alcohol syndrome (FAS): Combination of mental, motor, and developmental abnormalities affecting the offspring of some women who drink heavily during pregnancy.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Drug Intake  Nicotine - Maternal smoking has been identified as the single most important factor in low birth weight in developed countries.  Caffeine - Four or more cups of coffee a day during pregnancy is related to increased risk of sudden death in infancy.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Drug Intake  Marijuana and cocaine - Lead to:  Birth defects  Low birth weight  Withdrawal-like symptoms at birth  Increased risk of attention disorders and learning problems later in life

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Maternal Illness  Acquired immune deficiency syndrome (AIDS):  Viral disease that undermines effective functioning of the immune system.  Perinatal transmission - Virus may cross over to the fetus’ bloodstream through the placenta.  During pregnancy, labor, or delivery or, after birth, through breast milk  Offspring of mothers with diabetes likely to develop a wide range of birth defects.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Maternal Illness  Infections  Toxoplasmosis - Infection caused by a parasite harbored in the bodies of cattle, sheep, and pigs and in the intestinal tracts of cats.  Typically produces either no symptoms or symptoms like those of the common cold.  Thyroid deficiency  Rubella - Almost certain to cause deafness and heart defects in a baby if contracted by the mother.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Maternal Anxiety and Stress  Some tension and worry during pregnancy are normal and do not necessarily increase risks of birth complications such as low birth weight.  Moderate maternal anxiety may even spur organization of the developing brain.  Unusual maternal stress may have harmful effects on the unborn child.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Maternal Age and Outside Environmental Hazards  Maternal age  Chance of miscarriage or stillbirth rises with maternal age.  Outside environmental hazards  Air pollution  Chemicals  Radiation  Extreme heat and humidity

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Paternal Factors Men’s exposure to the following may result in abnormal or poor quality sperm: Lead Marijuana or tobacco smoke Large amounts of alcohol or radiation DES Pesticides or high ozone levels Men who smoke have an increased likelihood of transmitting genetic abnormalities. Pregnant women’s exposure to the father’s secondhand smoke has been linked with: Low birth weight Infant respiratory infections Sudden infant death Cancer in childhood and adulthood Older fathers may be a significant source of birth defects due to damaged or deteriorated sperm.

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Table 4.3 – Teratogen Effects

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Disparities in Prenatal Care  Increasing number of multiple births with heightened risk of death within the first year  Early births  Benefits of prenatal care are not evenly distributed  Ethnic disparity in fetal and postbirth mortality

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Need for Preconception Care  Research-based guidelines for preconception care for all women of childbearing age  Physical examinations and the taking of medical and family histories  Vaccinations for rubella and hepatitis B  Risk screening for genetic disorders and infectious diseases such as STDs

Copyright © 2014 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education Need for Preconception Care  Counseling women to:  Avoid smoking and alcohol  Maintain a healthy body weight  Take folic acid supplements