Preconception and Prenatal Period PDF

Preconception and Prenatal Period Where it all begins! After undoing IVF, Leanne is delighted to learn that she is pregnant Conception and Fertilization Leanne recalls that she experienced some minor bleeding around the time that she was expecting her period, just prior to finding out about her p...

Preconception and Prenatal Period Where it all begins! After undoing IVF, Leanne is delighted to learn that she is pregnant Conception and Fertilization Leanne recalls that she experienced some minor bleeding around the time that she was expecting her period, just prior to finding out about her pregnancy. What might be the cause of this bleeding? Fetal Membrane Development  FETAL STAGES 1 2 3 4 5 6 7 8 9 Ovum or pre-embryo Fetus Embryo Week 9 onward Conception 15 days to 8 weeks to 14 days **most critical time***  EXPECTED DEVELOPMENT Neural tube Brain Closes by week 4 Cells of cerebral cortex begin developing by week 8 Heart Bones Embryonic heart Ossification begins starts beating day 17 week 8 GI System Palate Primitive stomach and Formed weeks 6-9 intestines developed week 4 Genitals Kidneys Secrete urine by Sex recognizable at week 12 12 weeks h  True or False 1. Oogenesis begins during the female childhood period 2. Sperm may survive in the female’s reproductive system up to 7 days 3. Implantation takes place 14 days after fertilization 4. The embryonic stage begins at conception and lasts until 14 days 5. The chorion is the outermost layer of the fetal membranes Why is amniotic fluid important?  Amniotic Fluid Barrier to infection Acts as a cushion Source of fluid Maintaining constant body temperature Preventing entanglement in membranes Freedom of movement for musculoskeletal development Repository for waste Enhances lung development Amniotic Fluid 700-1000ml present at birth < 300ml Oligohydramnios Renal abnormalities > 2L Polyhydramnios GI and other malformations Leanne mentions that she had a friend who had too little amniotic fluid. What is the name for the condition in which the client has too little amniotic fluid? Noting the functions of amniotic fluid, what might be potential causes of decreased amniotic fluid? What additional complications might arise as a result of not enough amniotic fluid?  Question time! A perinatal nurse should be aware of which fact about the amniotic fluid? A. It serves as a source of oral fluid and a repository for waste from the fetus. B. The volume remains about the same throughout the term of a healthy pregnancy. C. A volume of less than 300 mL is associated with gastrointestinal malformations. D. A volume of more than 2 L is associated with fetal renal abnormalities.  Umbilical Cord At term, the umbilical cord 30-90cm is: 2cm in length diameter Located centrally in placenta 1 vein Carries blood to embryo Carry blood from 2 embryo to the chorionic villi arteries  Placenta Respiration Oxygen diffuses from maternal blood into fetal blood Carbon dioxide travels opposite direction  Placenta Respiration Oxygen diffuses from maternal blood into fetal blood, carbon dioxide travels opposite direction Nutrition Supplies glucose, water, vitamins, fats, electrolytes, etc.  Placenta Respiration Storage Oxygen diffuses from Stores CHO, maternal blood into proteins, fetal blood, carbon dioxide travels calcium, and iron opposite direction to meet fetal needs Nutrition Supplies glucose, water, vitamins, fats, electrolytes, etc.  Placenta Respiration Storage Oxygen diffuses from Stores CHO, maternal blood into proteins, calcium, fetal blood, carbon and iron to meet dioxide travels fetal needs opposite direction Nutrition Excretion Supplies glucose, Allows for water, vitamins, fats, electrolytes, etc. elimination of waste products What can happen if…. The labouring client has decreased BP? The uterus is contracting excessively? The client smokes, uses cocaine? The pregnancy is post-dates  Placental Hormones HcG Progesterone Detected 8-10 days Maintains after conception endometrium Human Placental Decreases Estrogen Basis for pregnancy tests Lactogen (hPL) uterine Stimulates uterine contractility growth and Increases insulin resistance, facilitates glucose transport uteroplacental bloodflow across placenta Stimulates myometrial contractility Near the Onset of Labour…. Progesterone ____ and Estrogen ____  Viability Capacity of the fetus to survive outside the uterus 22-25 weeks considered threshold of viability  FETAL RESPIRATORY SYSTEM Pulmonary surfactants Line interior of alveoli Required for postnatal lung expansion Permit alveolar expansion Prevent alveolar collapse LUNG DEVELOPMENT 32 weeks There is a sufficient amount of surfactant 35 weeks 2:1 ratio of lethicin and sphingomyelin (L/S ratio) Lungs considered mature Place ntal dy hyperten sfunction, sion, eroid use COOL FACT corticost Certain maternal conditions cause STR decreased blood flow to ESS OR placenta Fetal hypoxia Increased secretion of fetal stress hormones Accelerates fetal lung development Increased alveolar and surfactant development  MORE COOL FACTS Fetus practices breathing while in utero Lung fluids decrease before birth Leanne underwent a cesarean section with her last child How might this mode of delivery have affected her baby’s respiratory function after birth? Fetal Circulatory System Fetal lungs do not function for respiratory gas exchange 01 Ductus venosis 02 Foramen ovale 03 Ductus artereosis Foramen Ovale Shunts blood from the right atrium to the left. “hole in the heart”  Connects the umbilical vein to inferior vena cava Ductus Venosus Ductus Arteriosus Short blood vessel Connects pulmonary artery with aorta Enables blood to bypass the lungs  Matching Time! A. Involves vasculature within the heart 1. Ductus venosus 2. Ductus arteriosus B. Connects the umbilical vein to the inferior vena cava 3. Foramen ovale C. Shunts blood from the right atrium to the left How is does the fetus maintain adequate oxygenation.... despite the fact that fetal lungs don’t exchange gas?  How is fetal oxygenation maintained despite the fact that their lungs don’t exchange gas? More 02 carrying Increased CO capacity Fetus has 50% more hemoglobin Fetal hemoglobin than pregnant Fetal heart carries 20-30% rate is 110-160 person more 02  How is fetal oxygenation maintained despite the fact that their lungs don’t exchange gas? More 02 carrying What condition do capacity these adaptations make Leanne’s infant Fetus has 50% more susceptible to more hemoglobin than pregnant Fetal hemoglobin after birth? carries 20-30% person more 02  GASTROINTESTINAL SYSTEM Swallow amniotic GI system mature fluid month 5+ by 36 weeks Waste products accumulate in digestive tract near term (meconium) HEPATIC SYSTEM Fetus can store glycogen Glycogen stores 2x that of adult at term Iron stored in liver Enough supply to last up to 6 months of age HEPATIC SYSTEM Lacks enzymes to conjugate bilirubin Risk for jaundice Cannot make key coagulation factors Sterile gut cannot synthesize vitamin K Vitamin K administered IM after birth Leanne asks about why most babies end up with some degree of jaundice after birth. What response do you provide?  RENAL SYSTEM Functioning in 1st Fully developed at trimester birth Low GFR Urine secreted into amniotic fluid Lacks ability to concentrate urine  NEUROLOGIC SYSTEM Neural tube closed Cephalocaudal by week 4 development Head to rump development At birth, brain ¼ of adult size Forebrain, midbrain, hindbrain develop by Lower body parts must do more week 5 growing to reach adult size  ENDOCRINE SYSTEM Thyroid Adrenal cortex Pancreas Thyroxine secreted Secretes insulin by week 8 Forms during 6th week week 20 Hormones secreted weeks 8-9  Why do infants of clients with poorly controlled diabetes in pregnancy require monitoring after birth?  Uncontrolled diabetes in pregnancy Maternal hyperglycemia Increased glucose to fetus r t h of Riskinjury bi Fetal macrosomia Fetal pancreas secretes Hypo g more insulin to regulate afte lycemia r bir th fetal blood glucose Fetal hyperinsulinemia Blocks fetal lung Hypoglycemia after birth maturation (after removal of maternal glucose supply)  Question time! Which of the following points about infants of pregnant clients with poorly-controlled gestational diabetes are true? (Select all that apply). A. They are at risk of experiencing hypoglycemia B. They are at risk of experiencing hyperglycemia C. They are at risk of being small for gestational age D. They are at risk of being large for gestational age  REPRODUCTIVE SYSTEM Males Females Testes begin Oogenesis begins at 16 descending around weeks week 28 Ovaries contain lifetime ova supply at birth  INTEGUMENTARY Subcutaneous fat deposited under skin from 32 weeks + Thin layer at birth Blood vessels less visible but remain relatively close to skin surface Vernix caseosa o Waxy white substance o Protects skin of the fetus o Begins to develop at 20 weeks ○ Scant at term  Lanugo ○ Fine hairs ○ Disappears by birth  You are working on the maternal/newborn unit. A family member asks if it is ok for them to visit their new grandchild if they have a cold. What is the basis for your response?  IMMUNOLOGIC Impaired phagocytosis PASSIVE IMMUNITY IgG crosses placenta IgA in breastmilk Delayed chemotactic response Fever? Fetus can produce IgM Decreased Minimal levels at birth complement levels  Twins Monozygotic twins Dizygotic twins Originate from a single zygote Originate from two zygotes “fraternal” “identical” Dizygotic Twins Monozygotic Twins C. Monochorionic B. Monochorionic monoamniotic diamniotic A. Dichorionic diamniotic Which one of these monozygotic twin pregnancy types has the highest risk of adverse outcomes?  Question time! What should a nurse be able to tell parents when they have questions about multiple births? A. Dizygotic twins (two fertilized ova) have the potential to be conjoined twins. B. Monochorionic monoamniotic twins have separate amnions C. Fraternal twins are same gender, usually male. D. Multiple births are more common because of the use of fertility drugs.  Matching! A. Client with a type of twin pregnancy 1. Monochorionic which can result in conjoined twins diamniotic B. Client with twins that originated from 2. Dizygotic one zygote but have two amniotic sac 3. Monochoriotic C. Client who is carrying both a male and monoamniotic female fetus  NURS 2002 Pre-class Worksheet and Study Guide Preconception and Prenatal Care 1. What are the purposes of amniotic fluid? -Source of fluid -Acts as a cushion -Maintaining constant body temperature - Preventing entanglement in membranes - Repository for waste - Enhances lung development - Freedom of movement for musculoskeletal development 2. How much amniotic fluid is typically present at birth? 700-1000ml present at birth 3. Describe how placental vasculature works to transport oxygen to and from the embryo (e.g. number, types, and purpose of vessels) 2 arteries- Carry blood from embryo to the chronic villi 1 Vein- Carries blood to embryo 4. List the functions of the placenta. Respiration Oxygen diffuses from maternal blood into fetal blood Carbon dioxide travels opposite direction Nutrition Supplies glucose, water, vitamins, fats, electrolytes, etc. Storage Stores CHO, proteins, calcium, and iron to meet fetal needs Excretion Allows for elimination of waste products Explain what is meant by the term fetal viability. Capacity of the fetus to survive outside the uterus 22-25 weeks considered threshold of viability List the three unique vascular structures of the fetal circulatory system. Foramen Ovale Shunts blood from the right atrium to the left. “hole in the heart” Ductus Venosus Connects the umbilical vein to inferior vena cava Ductus Arteriosus Short blood vessel Connects pulmonary artery with aorta Enables blood to bypass the lungs Explain how a lack of fetal renal function (more specifically inadequate urine) can lead to changes in the amount of amniotic fluid. Lack of renal function can lead to changes of the amount of ammonitic fluild which can increase risk for baby to develop Oilgohydrmrainos which is less than 300ml. Explain the difference between dizygotic and monozygotic twins. Dizygotic twins Originate from two zygotes “fraternal Monozygotic twins Originate from a single zygote “identical’ 1. Monochorionic diamniotic Client with twins that originated from one zygote but have two amniotic sac 2. Monochorionic monoamniotic Client with a type of twin pregnancy which can result in conjoined twins  In-class activity Preconception and Prenatal Period True or False? As we move through the lecture, identify if each of the following points is true or false. Provide rationale for this response. FETAL DEVELOPMENT True (why?) False (why?) The chorion is the innermost layer of False fetal membrane and comes in direct contact with amniotic fluid Products of conception are referred to as False a fetus from the 6 week mark onward A fetus is being examined by ultrasound True at 9 1/2 weeks. It is too early, at this point, to visualize whether the fetus has male/female anatomy. A client will be diagnosed with False oligohydramnios if they have > 2L amniotic fluid The umbilical arteries carry blood from False the mother to the fetus The placenta is able to transport iron to Ture the fetus HcG cannot be detected until 2 weeks False after a missed period A fetus is considered viable from 20 False weeks onward Fetal lungs are considered mature from False 30 weeks onward The ductus venosus connects the False pulmonary artery with the aorta The fetal GI system is considered fully False mature from month 5 onward Vitamin K is administered after birth to False assist with the excretion of bilirubin to prevent jaundice The neural tube typically closes by week False 8 The fetal pancreas begins secreting True insulin by week 20 The fetus has ample subcutaneous fat by False week 32 Babies born at term should be fully False covered in vernix caseosa A baby who has excessive amounts of True lanugo at birth has most likely been born preterm All immunologic cells are fully functional False in the newborn, resulting in a stronger ability to fight off bacterial invaders A male and a female are twins. It should False be presumed that they are monozygotic twins