a. Read the comprehensive nursing content review

• Learning Step / Activity 1. Check your mastery of Maternity Nursing
• Review
• Read the comprehensive nursing content review
• Answer review questions on Maternity Nursing
• Review answers and rationales for each test questions

(1) The rationales for correct answers reinforces learning (2) The rationales for incorrect answers corrects knowledge deficits and identifies areas of focus for further study

• Fetal development
• Terms

(1) Zygote-Formed by the union of the sperm and ovum.(2) Embryo-Developing baby from the 3rd week to the end of the 8th week after fertilization.(3) Fetus- From the 9th week after fertilization until delivery, the developing baby is called a fetus.

• Zygote Stage: The Zygote develops in 2 distinct areas, the amniotic cavity and the yolk sac.

(1) Amniotic cavity-The walls of this cavity are lined with ectoderm (outer layer of embryonic tissue that develops the skin, hair and nails) and filled with amniotic fluid.(2) Yolk-Sac-Lined with the endoderm (innermost cell layer that develop into the lining of the cavities and passages of the body, and develops into the covering of most internal organs). It supplies nourishment until implantation.(3) Mesoderm-This is a third area where Zygote development occurs. It is located between the 2 germ cells (ectoderm and endoderm) and develops into all types of muscles, connective tissue, bone marrow, blood, lymphoid tissue and epithelial cells.(4) The embryo develops at the location of implantation, where all 3 of the above listed layers (ectoderm, endoderm and mesoderm) meet. This location is known as the trilaminar embryonic disk.

• Embryonic Stage

(1) The 3 primary cell layers differentiate into tissue and layers from the placenta and embryonic membranes.(2) Growth is rapid! A simple heartbeat begins and basic forms of all the major organ systems begin.(3) By the end of this stage, the embryo has developed a human appearance.(4) During this stage, teratogenic agents (drugs, viruses, radiation, infectious agents) can cause serious harm to the embryo.1

• Stages of Development of the Embryo

(1) Week 3: The first body segments appear: (a) Neural tube forms.(b) Primitive Brain.(c) Primitive Spinal Cord.(2) Week 4: The embryo is now 1/5th inch long, and the head is a third of its total length. The

following begins to form:

(a) Heart pumps blood.(b) Neural tube closes.(c) Digestive Tract- esophagus and trachea separate; stomach forms.

(3) Week 5:

(a) The heart starts to pump blood, has 2 chambers.

(b) Limb buds appear.(c) Major divisions of the brain can now be discerned.

(4) Week 6:

(a) Heart has 4 chambers.(b) External ears develop from skin folds.(c) Eyes begin to take shape.

(5) Week 7: Development is proceeding rapidly.

(a) The face is now formed with eyes, nose, lips and tongue.(b) Tiny bones and muscles appear beneath the thin skin. Even tiny primitive milk teeth can be seen.

(6) Week 8:

(a) The embryo is now a little more than 1 inch long.(b) Fingers and toes are formed.(c) Purposeful movements occur but mother can't feel these yet.(d) Heart beats at 40-80 beats/minute.

• The fetus- at 9 weeks the genitalia are well developed and sex of the baby determined.

(1) Week 10: The fetus assumes a more human shape as the lower body rapidly develops.

(a) Heartbeat detected by Doppler.(b) The first movement begins.(2) Week 16: All organs and structures have been formed, and a period of simple growth begins.

(3) Week 20:

(a) The fetus is now following a regular schedule of sleeping, turning, sucking, and kicking.(b) May be considered as the point of viability.(c) Lanugo covers the fetal body.

(4) Week 24:

(a) The fetus now weighs about 820 grams.(b) The eyes are complete, and are capable of opening and closing.

(5) Week 28:

(a) Fetal weight increases to 1300 grams.(b) Nervous system begins some regulatory functions.

(6) Week 32: Fully developed skeletal system is soft and flexible.

• Fetal vs. Neonatal Circulation
• Fetal circulation provides oxygen and nutrients to the fetus and disposes of carbon dioxide and other

waste products from the fetus.(1) Oxygenated blood is brought to the fetus by the umbilical vein and enters the fetal liver, where it branches.(2) The first branch (portal sinus) carries some of the oxygenated blood to the portal circulation and empties, via the hepatic vein, into the inferior vena cava.(3) The second branch (ductus venosus), carries most of the blood directly into the inferior vena cava, where it mixes with blood returning from the lower limbs, abdomen, and pelvis of the fetus to the fetal heart.(4) Blood entering the heart from the vena cava is directed across the right atrium through the foramen ovale to the left atrium.(5) Blood is then ejected from the left ventricle into the aorta and further circulated to the coronary arteries, brain, and upper extremities.(6) Venous blood returning from this region returns to the right atrium through the superior vena cava and is directed downward through the tricuspid valve into the right ventricle.(7) It is then pumped into the pulmonary artery, where the majority of the blood is shunted to the descending aorta through the ductus arteriosus and perfuses the lower body.(8) Only a small amount of blood enters the fetal lungs as a result of high pulmonary resistance.3

• Circulation Changes at Birth

(1) With the first breath, the newborn's lungs expand and the fluid within them is absorbed into the pulmonary circulation.(2) With that first breath, pulmonary and right heart pressures fall and systemic pressures begin to rise with the removal of the placenta.(3) The foramen ovale closes as the pressure in the left atrium exceeds the pressure in the right atrium.(4) The ductus arteriosus closes with the increased oxygen content of the newborn's blood.

• Common Complications of Pregnancy
• Hyperemesis gravidarum-excessive nausea and vomiting, which significantly hinders nutritional status

and fluid balance and causes electrolyte and metabolic imbalances.

• Bleeding disorders of early pregnancy.

(1) Spontaneous Abortion-pregnancy, which ends before viability (20 weeks gestation) from natural causes.(2) Ectopic Pregnancy- when the fertilized ovum (zygote) is implanted outside the uterus.

• Late pregnancy bleeding

(1) Placenta Previa-occurs when the placenta develops in the lower part of the uterus.(2) Abruptio Placentae-is the premature separation of a placenta that is normally implanted.

• Pregnancy induced hypertensio-Elevation of blood pressure in a previously normotensive woman after

20 weeks gestation, proteinuria and generalized edema.(1)Mild Preeclampsia - SBP 140-160 mmHg and DBP 90-100 mmHg. Trace protein in urine and liver enzymes are minimally elevated.(2)Severe Preeclampsia - SBP > 160 mmHg and DBP>110 mmHg on two separate occasions 6 hours apart. Urine protein is >5g/24h. Urine output less than 500cc/24 hours. Liver enzymes are markedly elevated.(3)Eclampsia - Generalized seizures with oliguria (Preeclampsia progresses to eclampsia when convulsions occur).

• . Blood incompatibilities-a condition that occurs after maternal exposure to Rh-positive blood. Occurs

between an Rh-negative mother and an Rh-positive fetus, which can result in the mother's antibodies destroying the newborn's red blood cells.

• Components of the Birth Process

a.The powers - forces that cause the cervix to open and that propel the fetus downward through the birth canal.(1)Uterine contractions