NURS368 Exam 1

Where does fertilization occur?

Where does fertilization occur?

distal 3rd of the fallopian tube (near ovary), enters uterus 3 days later

How long do sperm survive?

1-2 days

How long do sperm remain in the female tract?

up to 80 hours

Embryonic Period

Extends from beginning of the third week until the eighth week after conception, by end of 8th week all organ systems in place but developing

What period do teratogens cause major structural and functional damage to developing organs?

Embryonic period

Week that embryo develops heartbeat

4th week of gestation

Fetal Period

Beginning 9 weeks after conception and extending until birth, rapidly dividing cells become fetus, dramatic growth and refinement of established organs

12 Weeks Gestation

Fetus: 8cm long, 45 g
Sucking reflex
Fetal sex determination
Lanugo develops
Fetus excretes urine into amniotic fluid
Baby's heart rate heard with doppler (10-12 weeks)

When can a fetal heart rate be heard with a doppler?

10-12 weeks gestation

16 Weeks Gestation

Fetus: 14 cm, 200 g
Swallowing amniotic fluid
Quickening occurs
Eyes face forward rather than to the side

What is quickening and when does it occur?

Fetal movement, can be felt at 16 weeks (earlier if mom has been pregnant before)

20 Weeks Gestation

Fetus: 19 cm, 450 g
Vernix caseosa/lanugo covers entire body
Fetus reacts to loud noises
Fetal movement felt by all moms
Brain developing rapidly

Vernix

Thick, greasy substance that forms protective coating on baby's skin in utero

Lanugo

Fine, soft, downy hair that covers the baby's skin in utero

When are fetal movements usually felt by all moms?

16-20 weeks gestation

20 Weeks Gestation

Mom definitely should feel fetal movement
Fetal heartbeat can be heard with fetoscope

24 Weeks Gestation

Fetus: 23 cm, 820 g
Eyebrows, eyelashes, fingernails
Able to hiccup
Activity increases
Fingerprints, footprints develop
Surfactant production begins

Surfactant

Slippery, soap-like substance needed for breathing at birth, starts to be produced at 24 weeks; reduces surface tension in alveoli so they don't collapse with each breath

28 Weeks Gestation

Fetus: 27 cm, 1300 g
Eyes open and close (~26 weeks)
Lungs not fully mature
SubQ fat deposition

32 Weeks Gestation

Fetus: 30 cm, 2100 g
Rapid growth
Tremendous brain development
Lanugo begins disappearing

38-40 Weeks Gestation

Fetus: 36 cm, 3400 g
Fills total uterus
Mature lungs
Fully developed, able to survive outside utero
Vernix present in creases/skin folds
Lanugo present on upper shoulders/back
Firm ear cartilage
Fingernails extend past fingertips
Testes palpable in scrotum

Auxiliary Structures of Pregnancy

Placenta, Umbilical Cord, Fetal Membranes

Functions of the placenta

Metabolic and gas exchange, hormone production (progesterone, estrogen, hCG, hPL)

When is the placenta fully functional?

Between 8th and 10th week of pregnancy

Describe vascular characteristics of umbilical cord

1 umbilical vein (carries oxygenated and nutrient rich blood from mom to fetus)
2 umbilical arteries (carries deoxygenated blood/waste products from baby to mom)

Dirty Duncan

Maternal side of placenta, rough where it attaches to uterus

Shiny Schultz

Fetal side of placenta, smooth

Where does exchange of substances between mother/fetus occur?

Within intervillous space of placenta

Why are mother's blood and fetal blood separated?

Avoids mixing of fetal and maternal blood which may not be compatible (ABO types, Rh factor)

Amnion

Inner membrane of amniotic sac, develops from embryoblast

Chorion

Outer membrane of amniotic sac, develops from trophoblast

Amniotic Sac / Bag of Waters

Membranes containing fetus and amniotic fluid, helps maintain sterile environment and prevent bacterial infiltration

Amniotic Fluid Characteristics

Usually clear
Composed of water, proteins, carbohydrates, lipids, electrolytes, fetal cells, lanugo, vernix
Peaks at 500-1000 mL of fluid at term

1st trimester amniotic fluid production

Amniotic membrane

2nd/3rd trimester amniotic fluid production

Fetal kidneys

Polyhydramnios

Excess amniotic fluid greater than 2000 mL
Increased incidence of chromosomal disorders, CNS or GI defects

Oligohydramnios

Decreased amount of amniotic fluid less than 500 mL at term, or 50% reduction in nL amount
Increased incidence of congenital renal problems

Functions of amniotic fluid

Cushions fetus
Prevents adherence of embryo to membranes
Allows fetal movement and musculoskeletal development
Consistent thermal environment

Duration of Pregnancy

280 days
40 weeks
9 months
3 trimesters

First trimester

Weeks 1-13

Second trimester

Weeks 14-26

Third trimester

Weeks 27-40

Antepartum

1st day of last menstrual period (LMP) to onset of labor

Intrapartum

Begins with the onset of labor, ends with expulsion of placenta

Postpartum

Begins with expulsion of placenta, lasts 6 weeks

Naegele's Rule

Most common method of determining due date; begin with 1st day of LMP, subtract 3 months, add 7 days

Antepartal physiological changes: vagina/vulva

Increased vascularity
Bluish-purple appearance
Loose connective tissue
pH becomes more acidic
Increased chance of yeast infection

Antepartal physiological changes: Cervix

Increased vascularity
Chadwick's sign
Goodell's sign
Secretion of mucous to form mucous plug

Chadwick's Sign

Blue-purple coloration of cervix due to increased vascularity

Goodell's Sign

Cervical softening

Antepartal physiological changes: Uterus

Amenorrhea
Braxton-Hicks cx's (aid placental perfusion)
Hegar's sign
Growth increases

Hegar's Sign

Compressibility and softening of cervical isthmus

Antepartal physiological changes: ovaries

Secrete progesterone from corpus luteum until placenta takes over
Ovulation stops

What is the hormone of pregnancy, and what other hormones does it inhibit?

Progesterone: inhibits FSH and LH, stopping ovulation

Antepartal physiological changes: breasts

Increased size
Tenderness
Visible veins
Colostrum (12 weeks)
Larger nipples w/ increased pigmentation

Antepartal physiological changes: cardiovascular system

CO increase by up to 50%
Slightly elevated pulse (15-20 bpm)
Systolic murmurs possible
Increased blood volume (40-45%)
Decreased BP through 2nd TM
Supine hypotension

When does mom's BP return to pre-pregnancy levels?

By term r/t decrease in peripheral vascular resistance

Antepartal physiological changes: blood

Anemia of pregnancy
RBC increase (20-30%)
Plasma volume increase (40-60%
Leukocyte increase (5,000-15,000 up to 25-30,000 during labor)
Platelets slightly decrease
Increased coagulation factors
Increased demand for iron

Why do we teach moms to take Ferrous Sulfate with vitamin C?

Enhanced absorption

Antepartal physiological changes: Respiratory

Elevated diaphragm, flared rib cage
Increased TV (30-40%)
Increased O2 consumption (15-20%)
Rhinitis, congestion
SOB when reclining (3rd TM)
Epistaxis (nosebleeds)

Antepartal physiological changes: GI

N/V (morning sickness)
Gum bleeding
Displaced stomach, intestines
Heartburn
Excessive saliva
Slowed motility, delayed gastric emptying
Bloating, constipation, hemorrhoids
Pica
Gallbladder/gallstones

Antepartal physiological changes: metabolic changes

Potential increase of blood glucose from insulin resistance in last half of pregnancy (gestational diabetes)

Guidelines for total weight gain during pregnancy

Underweight: 28-40 lbs
Normal: 25-35 lbs
Overweight: 15-25 lbs
Obese: 11-20 lbs

Antepartal physiological changes: urinary system

Urinary frequency (1st, 3rd TM)
Increased GFR
Glycosuria

Antepartal physiological changes: vascular

Hemorrhoids
Varicosities in legs/labia

Antepartal physiological changes: integumentary

Skin pigmentation (hyperpigmentation, linea nigra, melasma)
Striae Gravidarum (stretch marks)
Spider nevi
Hyperactive sweat/sebaceous glands
Hair growth
Edema

Antepartal physiological changes: musculoskeletal

Pelvic joint/ligaments relax
Center of gravity changes
Increased lumbosacral curve
Waddling
Diastasis recti
Lordosis

Antepartal physiological changes: Endocrine

Pituitary: increases prolactin
Thyroid: enlarges, crucial for fetal brain
BMR: increases up to 25%

Presumptive (Subjective) Indications of Pregnancy

Amenorrhea, morning sickness, fatigue, urinary frequency, breast tenderness, Chadwick's sign, fetal movement

PRESUME acronym

Period absent
Really tired
Enlarged breasts
Signs (Chadwicks)
Urinary frequency
Movement perceived
Emesis

PROBABLE acronym

Positive test
Rebound (ballottement)
Outline of fetus
Braxton Hicks cx
A soft cervix
Belly
Lower uterine segment soft
Enlargement of abdomen

Are pregnancy tests probable or positive signs of pregnancy?

Probable: detection of hCG in blood/urine, not 100% accurate

Positive (Diagnostic) Indications of Pregnancy

Fetal movement (provider confirmed), FHR, delivery of baby, ultrasound, visible movement

FETUS acronym

Fetal movement
Electronic detection FHR
The delivery
Ultrasound
See visible movement

Normal psychological maternal responses to pregnancy

Uncertainty, ambivalence, self as primary focus, introversion, body image changes, sexuality changes, vulnerability, increasing dependence, preparation for birth

Rubin's 4 major tasks of pregnancy

Ensuring safe passage for mom/baby
Ensuring social acceptance of child by SOs
Attaching to child
Giving self to demands of motherhood

Normal psychological responses of father to pregnancy

Sense of pride, feeling left out, confused by partner response, resentment over relationship changes, increased sense of responsibility

Couvade syndrome

AKA sympathetic pregnancy, father experiences similar physical/behavioral changes to pregnant mother (hormone alteration, weight gain, morning sickness, disturbed sleep)

How do both parents prepare for their new roles?

Enhanced communication, clarifying partner expectations, solving unresolved conflicts

Cultural assessment of pregnancy

Mom's concerns, where does mom obtain healthcare info, encouraged or discouraged foods, mom's preparation for baby

Three phases of the ovarian cycle

Follicular, Ovulatory, Luteal

Follicular Phase

Day 1-14
First day of menstrual bleed
LH and FSH rise
Graafian follicles grow
Estrogen levels rise
Endometrium grows
Ends with ovulation

Ovulatory Phase

Day 13-14
Lasts 16-36 hours
Surge of LH and FSH
Ova released from follicle for fertilization
Ovum fertile for 6-24 hours
Estrogen levels peak
Progesterone levels rise

Luteal Phase

Day 15-28
Endometrium thickens if fertilization occurs
hCG produced by fertilized egg
Ruptured follicle becomes corpus luteum (provides progesterone in pregnancy)
No fertilization -> corpus luteum degenerates, progesterone drops
Menses begins 14 days post ovulation

4 phases of endometrial cycle

Menstrual, Proliferative, Secretory, Ischemic

Menstrual Phase

Days 1-6
Low estrogen levels
Resting endometrium
Endometrial tissue sloughing if no pregnancy

Proliferative phase

Days 7-14
Starts after menses
Ends with ovulation
Endometrium thickens, becomes vascular

Secretory Phase

Days 15-26
Starts after ovulation
Endometrium continues thickening
Onset of menses if no pregnancy

Ischemic Phase

Days 27-28
Estrogen and progesterone drop
Menses begins

Fertilization

Occurs in fallopian tube when sperm nucleus enters nucleus of egg

Zygote

Fertilized egg

Implantation

Blastocyst into uterine lining 5-6 days after fertilization, normally in upper, posterior uterine wall

Blastocyst

Cell mass after about 5 days

Oocyte

Sperm nucleus that has entered nucleus of egg

Embryo

Time of implantation through 8 weeks gestation

ACOG goals of prenatal care

Ensure healthy baby
Minimize maternal risk
Early/accurate estimate of gestational age
Identify at risk patients
Anticipate/prevent complications
Patient education

Prenatal Visit Frequency

Initial visit (at 6-10 weeks)
Every 4 weeks (up to 28 weeks)
Every 2 weeks (28-36 weeks)
Every week (36-40 weeks)
More frequently w/ risk factors
1-4-2-1 rule

Define early and adequate prenatal care

Begins in first trimester with 80-100% of appointments attended by expecting mother

Define late prenatal care

Begins in the 3rd TM

Late preterm

34-36 6/7 weeks