Exam 2 Flashcards
Three Cycles related to Pregnancy
Endometrial Cycle—thickening of the endometrium for pregnancy; shed 2 weeks after ovulation if no pregnancy
Hypothalamic-Pituitary Cycle—pituitary sends signals to the ovaries to develop and mature eggs
Ovarian Cycle—ovarian follicles are stimulated to mature and release an egg; implantation of fetus 7-10 days after ovulation
3 phases of ovarian cycle
Follicular: begins with the onset of menses; 1st day of menstrual cycle
Ovulatory: begins when estrogen levels peak and ends with release of oocyte (egg)
Luteal: begins on day of LH surge-Lasts approx. ~ 14 days (If pregnancy occurs, releases progesterone and estrogen until placenta matures; if no pregnancy; corpus luteum degenerates and progesterone decreases
Menstrual Cycle
Length
Duration
Total blood loss
Regularity impacted by (3)
Length: 24-36 days (average is 28; but varies cycle to cycle)
Duration: 3-6 days (average 5 days)
Total Blood loss: 20-80 mL (average 50 mL)
Regularity impacted by stress, exercise, nutrition
Prostaglandins
Action
Effects (7)
Action: oxygenated fatty acids; hormones
Effects
- Ovulation (ovum trapped if prostaglandin does not increase w/ LH surge)
- Fertility
- Changes in cervix and cervical mucus
- Tubal and uterine motility
- Sloughing of endometrium (menstruation)
- Onset of abortion (spontaneous and induced)
- Onset of labor (term and preterm)
Three ovulation indicators
- Basal body temperature: drops 1 day (< 37 C) prior to ovulation then rises 1 degree at ovulation for 10 -12 days
- Spinnbarkeit: Change in cervical mucus (abundant, watery, clear, more alkaline, ferns under microscope)
- Mittleschmerz- localized abdominal pain that coincides with ovulation
Most cost-effective genetic test
Obtaining a family history going back 3 generations on both maternal and paternal sides
(most other genetic tests are not done unless risk factors)
Risk factors for miscarriages (9)
- chromosomal abnormalities (25% of first trimester losses)
- Prior pregnancy loss
- Advanced maternal age (> 35 yrs)
- Endocrine abnormalities (DM, luteal phase defects)
- Drug use or environmental toxins
- Autoimmune disorders (SLE)
- Infections
- Uterine or cervical abnormalities
- black woman
How to obtain karyotype of fetus? (4)
- amniocentesis (cells from amniotic fluid)- risk for miscarriage
- cells from fetal blood
- cells from fetal skin
- CVS-Chorionic Villi sampling (sample from placenta b/w 9-11 weeks)
Autosomal Recessive Disorders
5 disorders
- Sickle Cell Anemia- abnormal hgb molecule reducing oxygen carrying capacity; present among AA and Mediterranean
- Tay Sachs Disease- hexosaminidase deficiency affecting lipid storage usually dead by 2 yrs; among Ashkenazi Jews and French Canadians in Quebec
- Cystic Fibrosis- exocrine glands produce excessive viscous secretions leading to respiratory and digestive problems; among Caucasians
- Phenylketonuria (PKU)- phenylalanine hydroxylase deficiency so limit phenylalanine (amino acid) in diet; among Northern Europeans
- Thalassemia
Autosomal Dominant Disorders
2 disorders
- xeroderma pigmentation
- huntington’s disease ( uncontrollable muscle contractions b/w 30-50 yrs then loss of memory and personality)
Autosomal Recessive vs Autosomal Dominant
Autosomal Dominant-If one parent carries the gene, 50% chance of child being affected.
Autosomal Recessive Inheritance - both parents must be carriers and both pass on abnormal gene to child for trait, disorder, or disease to be present (1 in 4 chance each pregnancy)
Risk factors for chromosomal abnormalities (6)
- maternal age > 35 yrs by due date (esp trisomy 21)
- paternal age 50 or older
- History of miscarriage or stillbirth
- Diabetes in mom (not fam hx)
- Family history of birth defects/genetic diseases (Huntington’s, Down Syndrome, Muscular dystrophy, hemophilia, cystic fibrosis, intellectual disability)
- Family history of hypercholesterolemia and PKU
4 Tips for coping with prenatally diagnosed genetic disorder
- Provide ongoing info on genetic disorder (including appropriate websites)
- Refer couple to support group for parents w/ children w/ same genetic disorder
- Encourage open communication b/w couple about feelings and concerns
- Let couple know that it is normal for them to grieve over the loss of their “dream child”
Sex-linked abnormalities
Disorders (4)
Turner syndrome (short stature, risk for cardiac defect, failure of ovaries to develop) in Females=45, X.
Klinefelter Syndrome (infertility) in Males= 47, XXY
X-Linked- hemophilia (Lack of factor VIII impairs chemical clotting)
X-linked- Duchenne’s-muscular dystrophy (replace muscle tissue w/ adipose or scar tissue so progressive loss of muscle function; fatal by 20 yrs)
3 Conditions for Fertilization
Ovulation occurs -> mature ovum enters a patent fallopian tube (fimbriae of fallopian tube capture ovum and cilia propel ovum to uterus)
Sperm cells are deposited in vagina & travel to fallopian tube surviving 48 hrs (max 5 days)
One sperm cell must penetrate ovum usually in outer third of fallopian tube (ampulla) within 24 hours of ovulation.
Pre-embryonic fetal development
Zygote (3)
Morula (3)
Zygote
- secretes BhCG to signal pregnancy
- has 46 chromosome
- single fertilized oocyte
Morula
- develops by day 3
- 16-cell sphere
- outer cells secrete fluid creating blastocyst
Pre-embryonic fetal development
Blastocyst (4)
Blastocyst
- develops by day 5
- fetus develops from inner cell mass (embryoblast)
- placenta and membranes develop from outer layer (trophoblast)
- trophoblast becomes chorion and secretes enzymes for implantation around 6-10 days
Embryonic Period (3)
- Week 3 through 8 of pregnancy
- Period of organogenesis - highest risk of structural damage by teratogens (chemicals, drugs, viruses, fever)
- rapid hyperplasia of fetal cells
Pregnancy Lengths
Total Pregnancy
Conception
1st trimester
2nd trimester
3rd trimester
Total Pregnancy: 40 weeks, 280 days
Conception: 2 weeks after 1st day of menstrual cycle
1st trimester: 1st day of LMP through 13 weeks
2nd trimester: Week 14 through 26
3rd trimester: Week 27 through 40+
Teratogenic Effects: 3-8 weeks (9)
- Neural tube defects (anencephaly, spina bifida) at 4 wks due to inadequate folic acid
- Limb defects
- Intellectual disability
- Cleft lip, cleft palate
- Deafness
- Microphthalmia (small eyes), cataracts, glaucoma
- Enamel hypoplasia, staining
- Masculinization of female genitalia
- Heart Defects (Truncus arteriosus, VSD, ASD (heart problems)
Teratogenic Effects: 9 weeks to delivery (3)
- Functional defects (IUGR or reduced organ size)
- Minor anomalies( ears, eyes, teeth, palate, external genitalia)
- CNS (vulnerable throughout pregnancy
Fetal Alcohol Syndrome characteristics (4)
- low birth weight
- microcephaly and mental retardation
- unusual facial features due to midfacial hypoplasia
- cardiac defects.
Teratogens (10)
- Tobacco (IUGR, preterm, SIDS, nicotine = vasoconstrictor so decreased perfusion)
- Heroin, methadone (IUGR, prematurity, Neonatal abstinence syndrome)
- cocaine (increases maternal BP, IUGR, placental abruption, prematurity; organ defects)
- alcohol (> 1 drink/day– fetal alcohol syndrome)
- ionizing radiation (>10 rads)
- radioiodine
- Tetracycline
- carbamazepine (NTDs)
- ACE inhibitors (renal tubular dysplasia, IUGR)
- warfarin (spontaneous abortion, hemorrhage)
Infections and Fetal Anomalies (11)
- Toxoplasmosis (protozoan)- fetal demise, blindness, mental retardation
- Cytomegalovirus- hydrocephaly, microcephaly, cerebral calcification, mental retardation, hearing loss
- Syphilis (RPR)- skin, bone, or teeth defects; fetal demise
- Varicella- hypoplasia of hands and feet, blindness or cataracts, mental retardation
- Zika - microcephaly, blindness, hearing defects
- HSV
- Influenza
- HIV
- Chlamydia
- HPV
- Rubella
Prenatal Screening: Fetal Anomalies
Offered to?
Types (2)
Results for quad (2)
- offered to all expectant women
Types
- Multiple Marker Screen (Triple, Quad or Penta Screen)– during 2nd trimester for Trisomy 21, Trisomy 18, NTD
- Cell free DNA (cfDNA) blood test for gender, trisomy 21 and 18 but not NTD
Results (quad screen)
- Alpha-Fetoprotein (AFP) is high = increased risk for NTDs
- Low AFP levels = increased risk for Trisomy 21 (Down Syndrome)
Prenatal Diagnostics: Fetal Anomalies
Offered to? (2)
Types (3)
- offered to high risk OR positive screening
Types
- Chorionic Villi Sampling (CVS) at 11-13 weeks
- Amniocentesis at 14-16 weeks (results in 2 weeks)
- Percutaneous Umbilical Cord Sampling (PUBS)- assess for fetal anemia, isoimmunization; diagnosis genetic disorders
Pre-embryonic: Germ layers
Mesoderm (5)
Mesoderm
- bones (4th week)
- muscles (4th week)
- kidneys (5th week)
- hematologic system (bone marrow, blood, lymphatic tissue)
- Heart (4th week beats; forms in 3rd week
Pre-embryonic: Germ layers
Ectoderm (4)
Ectoderm
- CNS
- Integumentary (skin, hair, nails, sweat, oral mucosa)
- optic
- otic
Pre-embryonic: Germ layers
Endoderm (3)
Endoderm
- GI (liver, pancreas, esophagus, stomach)
- Respiratory
- Thyroid
Membranes: Amniotic fluid
Function (6)
Function
- maintain body temp
- barrier for infection
- musculoskeletal development (freedom for movement and symmetrical growth via prevention of membrane tangling)
- fetal lung development (swallow fluid)
- electrolyte balance (urinates around 11 wks)
- cushion
Membranes: Amniotic fluid
Structure (4)
Structure
- Volume is important to fetal well-being (700-1000 mL)
- contains mostly water plus urine (urea), lanugo hair, epithelial cells
- usually clear (brown/yellow if meconium)
- maintained by amniotic membrane then fetal kidneys
Membranes: Amniotic fluid
Problems (2)
Problems
- Oligohydramnios (< 500 ml) cause reduced fetal lung development, renal problems
- Polyhydramnios (>1500-2000 ml) cause chromosomal, GI, cardiac, and NTDs
Fetal Period (3)
- 9 weeks to end of pregnancy
- refinement of structure and function
- viability (ability to live outside uterus, 22-25 weeks based on CNS and lung maturity)
Membranes: Umbilical cord
Function
Composition (2)
Problems (3)
Function: Supplies the embryo with maternal nutrients and oxygen
Composition
- Wharton’s jelly (CT cushions vessels from compression)
-2 arteries (carry deoxygenated blood from embryo to placenta), 1 vein (carry oxygenated blood from placenta to embryo- larger than 2 arteries)
Problems
- thin cord
- short cord
- cord w/ one artery and one vein (risk for cardiac or vascular anomaly)
Membranes: Placenta
Composition (3)
Problems (2)
Composition
- Chorionic villus (contains fetal blood vessels and imbeds in decidua basalis)
- intervillous space (contains maternal blood)
- Cell layer (prevents mixing of maternal and fetal blood)
Problems
- small placenta (poorly nourished and oxygenated child)
- teratogens can cross placenta (C, D, X drugs, live vaccines, viruses (rubella, cytomegalovirus)
Membranes: Placenta
Function (2)
Expected appearance
Function
- metabolic (exchange of gases, nutrients, wastes, and antibodies b/w fetus and maternal)
- endocrine gland (hCG, hCS, progesterone, estrogen, hPL, Growth hormone, Cortiotropin-releasing hormone)– insulin antagonists starting at week 6 or 7
Expected appearance
- maternal side dull, fetal side shiny
Membranes
Yolk Sac
Endometrium (2)
Yolk sac
- Becomes primitive digestive system
Endometrium
- Decidua parietalis (lines uterine cavity)
- Decidua basalis (maternal part of placenta; divided in cotyledons/lobes; hemorrhage here usually for miscarriage)
Hormones in Pregnancy: Follicle Stimulating Hormone (FSH)
Functions (5)
Secreted from the anterior pituitary
Stimulates growth of the ovarian follicles
stimulates the follicles to secrete estrogen.
Stimulates sperm production
Decreases in pregnancy (Amenorrhea)
Hormones in Pregnancy: Estrogen
Functions (6)
- Secreted from the follicle cells,
- promotes the maturation of the ovum
- Stimulates enlargement of breasts and uterus.
- Decreases maternal use of insulin.
- Increases vascularity
- responsible for hyperpigmentation
Hormones in Pregnancy: Luteinizing Hormone (LH)
Functions (2)
Secreted from the pituitary gland
Stimulates testosterone production
Hormones in Pregnancy: Progesterone
Functions (2)
- Facilitates implantation by thickening and making endometrium more vascular
- decreases uterine contractility to maintain pregnancy by relaxing smooth muscles
Hormones in Pregnancy: Human Chorionic Gonadotropin (hCG)
Functions (3)
- produced by fertilized ovum and chorionic villi
- Stimulates corpus luteum so it will secrete estrogen and progesterone until placenta takes over
- Pregnancy tests detect this hormone in 1st trimester
Hormones in Pregnancy: Prolactin
Function
Prepares breast for lactation
Hormones in Pregnancy: Oxytocin
Functions (2)
- Stimulates uterine contractions
- stimulates milk ejection from breasts (milk let-down or ejection reflex)
Hormones in Pregnancy: Human placental lactogen (hPL) and human chorionic somatomammotropin (hCS)
Functions (2)
- insulin antagonist (promotes fetal growth by regulating glucose)
- stimulates breast development in preparation for lactation.
Fetal Developmental Milestones: 9 weeks (2)
- urine in amniotic fluid
- male/female anatomy (9-12 weeks)
Fetal Developmental Milestones: 12 weeks (5)
- Placenta complete
- organ systems complete
- thumb sucking
- somersaults
- heart tone heard on doppler
Fetal Developmental Milestones: 16 weeks (3)
- meconium in bowel
- sucking motions
- skin transparent
Fetal Developmental Milestones: 20 weeks (6)
- hearing develops
- quickening
- vernix caseosa and lanugo covers body
- sleep/wake cycles
- insulin produced
- brown fat develops
Fetal Developmental Milestones: 24 weeks (4)
- rapid brain growth
- hiccups
- vernix caseosa = thick
- Lecithin (L) present (lungs begin producing surfactant)
Fetal Developmental Milestones: 28 weeks (5)
- Lungs allow gas exchange)
- hair on head
- eyes open and close
- senses develop (taste buds, process sounds)
- subQ fat develops
Fetal Developmental Milestones: 32 weeks (3)
- bones fully developed
- increased subQ fat
- Lecithin/sphingomyelin (L/S) ratio (1.2:1) - enough surfactant to increase survival
Fetal Developmental Milestones: 36 weeks (3)
- decreased amniotic fluid
- Lanugo disappears
- Lecithin/sphingomyelin (L/S) ratio > 2:1 (lungs mature)
Fetal Developmental Milestones: 40+ weeks (2)
- considered full term at 38 weeks
- Hepatic (enough iron for 5 months post birth)
Fetal Circulatory System
Functions
- ductus venosus (2)
- foramen ovale (2)
- ductus arteriosus (3)
Ductus venosus
- Connects umbilical vein to inferior vena cava
- Allows most of oxygenated blood to enter right atrium
Foramen ovale
- may not fully close till 3 months of age
- Opening b/w right and left atria which shunts oxygenated blood right-to-left
Ductus arteriosus
-lungs do not function for gas exchange; ductus arteriosus (b/w aorta and pulmonary artery) used to bypass lungs
- Majority of oxygenated blood shunted from left atria to aorta; small amount to lungs
- Constricts after delivery due to higher blood oxygen levels and prostaglandins
What do the following mean:
Mono-di
mono-mono
di-di
Mono-di: share placenta but own amniotic sac for monozygotic twins
Mono-mono: share placenta and amniotic sac for monozygotic twins
di-di: own placenta and own amniotic sac for fraternal twins twins
Presumptive Signs of Pregnancy (7)
- any subjective symptoms reported by patient
- Amenorrhea
- Nausea/vomiting (weeks 2-12)
- Breast changes (sore, enlarged) - wks 2-3
- Fatigue (1st trimester)
- Increased Urinary frequency (pressure of enlarged uterus)
- Quickening (sensation of fetal movement around 18-20 wks)
Probable signs of Pregnancy (7)
- Chadwick’s sign (bluish-purple cervix) - 6-8 wks
- Goodell’s sign (cervix softens w/ leukorrhea) - 8 weeks
- Hegar’s sign (softened lower uterine segment) - 6 weeks
- Uterine growth
- Skin hyperpigmentation (chloasma, linea nigra)
- Ballottement (tap of examiner finger causes fetus to bounce in amniotic fluid) - 16-18 wks
- Positive pregnancy test (hCG blood, urine or home test) - detects anywhere from 1 week before missed period to 4 weeks gestation
Positive signs of Pregnancy (3)
- Auscultation of fetal heart (normal: 110-160 bpm) - 10-12 wks
- Observation and palpation of fetal movement by provider - 20 wks
- Sonographic visualization (cardiac movement or gestational sac) - 4-8 wks
Determining Pregnancy Due Date
Naegele’s rule (2)
- 1st day of LMP + 7 days - 3 months = EDD
- inaccurate if irregular cycles or cycles > 28 days
Determining Pregnancy Due Date
Ultrasound (2)
- measure crown-rump length (< 14 weeks)
- measure Biparietal diameter, Head circumference, Femur length, Abdominal circumference (> 14 weeks)
Determining Pregnancy Due Date
Fundal height (4)
- in cm = gestational age starting at 10-12 weeks
- zero tape on symphysis pubis and top on fundus
- empty bladder prior to measurement
- unreliable in obese, IUGR, multi-gestation
Ultrasound: When indicated? (7)
- used when unclear hx of LMP or irregular cycles
- Pelvic pain or vaginal bleeding in first trimester
- Hx of repeated pregnancy loss or ectopic pregnancy
- Discrepancy b/w actual size and expected size of pregnancy based on history
- screen for aneuploidy (enlarged nuchal translucency i.e fluid filled space on dorsal of neck))
- Fetal biometric measurements (gestational age measurements, growth, activity, amnionicity, number)
- identify placental placement
Ultrasound: Transabdominal
Notes (3)
- Pt in supine position
- Full bladder necessary in first half of pregnancy
- Transmission gel and transducer placed on abdomen to create image
Ultrasound: Transvaginal
Notes (5)
- done in 1st trimester or if abdominal inconclusive b-c more accurate
- Pt in lithotomy position
- HCP uses sterile probe or transducer in vagina
- Assess for latex allergies
- Inform pt. they will feel pressure but not pain