Unit 2 Flashcards
Describe the anatomy of the uterus
Divided into two parts: corpus and cervix
- Corpus: upper triangular portion, upper 2/3 of uterus
- Rounded top: fundus
- Cervix: lower 1/3, meets body of uterus (corpus) at the internal os and connects with the vagina at the external os.
Big muscle; why we cramp during periods, contracts to push a baby out
Very elastic; has to stretch a lot during pregnancy
What is the purpose of the fallopian tubes and ovaries?
Two fallopian tubes and two ovaries arise from the side of uterus
Ovum (egg) is released from the ovary during ovulation every month and fertilized in the fallopian tube.
Tube serves as a warm, nourishing environment as zygote (fertilized egg) moves to the uterus.
What are the phases of a woman’s cycle?
- Follicular phase - what varies cycle length
- Ovulation
- Luteal phase - relatively constant (typically 14 days always)
A normal, typical cycle is 28 days, but this varies per woman
A cycle could be 21 days or 35 days; could differ each month.
Day 1 of cycle is your period, when hormones are at their lowest
Describe the process of conception
Occurs as a sequential process: Ovulation, fertilization, implantation in the uterus
1. When the ovum is released from the ovary, it is viable for 24 hours (if not fertilized, it will dissolve). Sperm is viable for 72 hours after intercourse
2. Fertilization takes place in the outer third of the uterine tube (ampulla). Sperm head contains enzyme which enables it to enter ova. After one sperm enters, cellular change occurs in ovum which makes it impenetrable to other sperm. “Cortical reaction” -> Zygote: united egg and sperm
Egg (23 chrom) + sperm (23 chrom)= zygote (46 chrom)
After fertilization: the zygote begins to travel the length of the tube to the uterus, which can take 3-4 days
3. Implantation occurs about a week after fertilization
Describe what the zygote transforms into from fertilization to implantation
Zygote: fertilized ovum
Morula: 3 days after fertilization (16 cell sphere)
Blastocyst: day 5 (distinct inner and outer cell mass with fluid in between) this ball of cells has begun to differentiate into an outer layer of cells (trophoblast) and an inner layer of cells (embryoblast)
Describe what makes up a blastocyst and what they develop into
Embryoblast (inner cells): develops into amnion (amniotic membranes) and embryo
Trophoblast (outer cells): develops into chorion and the placenta
Describe the process of implantation
- Occurs 6-10 days after fertilization (a week from when she would expect her period)
- The blastocyst buries itself into the endometrium; erosion of blood vessel occurs which could lead to light spotting; starts to release enzymes
- The outer trophoblast adheres to the endometrium (secretion of hCG begins)
- hCG begins production
Describe pregnancy length, Post-conceptual age vs. LMP dates
Pregnancy lasts ~ 40 weeks (9 calendar months) from the the first day of the last period. So first day of last menstrual period + 40 weeks = due date. This is the LMP date
Post-conceptual age is the age of the actual “pregnancy”. It is 2 weeks less than the LMP date
Describe the 3 stages of intrauterine development
- Ovum (preembryonic): conception until day 14
- Embryo: Day 15 until 8 weeks after conception (10 weeks LMP)
- The most crucial part of development, the foundation for all major organ systems is forming
- The embryo is highly susceptible to teratogens
- By end of this phase, the embryo takes on a very human-like appearance - Fetus: 9 weeks (11 weeks post menstrual) until the pregnancy ends
Describe the chorion and amnion
They are the 2 layers of membranes surround developing embryo
1. Chorion: develops from the trophoblast, contains chorionic villi on its surface, which are finger-like projections that tap into mom’s circulation and increases diffusion of oxygen.
2. Amnion: develops from the inner layer of the blastocyst (embryoblast); “amniotic sac.” It is the membrane around the baby.
Describe chorionic villi
Finger like projections that form from the trophoblast
Performs respiration for the fetus
- Obtain oxygen and nutrients from the maternal bloodstream
- Dispose of waste products in maternal blood
Describe what happens to the volume of amniotic fluid throughout pregnancy
The volume increases weekly (700 -1000 mL, or about a L, present at term)
The amount changes continuously. This is a result of…
- Amniotic fluid is constantly moving in and out of the fetal lungs
- The fetus also swallows amniotic fluid and will pee it out (fetal urine is a component of amniotic fluid)
- Can also be affected by mom’s hydration status
Describe oligohydramnios
Small amount of amniotic fluid: Less than 300 mL
Related to a compromised fetus, decreased fetal well-being
Also related to renal anomalies in the fetus: abnormal kidney, missing a kidney, cysts on kidney.
If seen on an ultrasound, mom will be sent to the hospital, and the first thing that is done is that mom is hydrated and fluid level is tested again after 24 hours,
Describe polyhydramnios
Large amount of amniotic fluid: 2 L or more
Not always a bad thing
Can be associated with GI anomalies in the fetus, such as esophageal atresia (baby is unable to swallow fluid)
Also associated with neural anomalies: meningocele, encephalocele; Also seen with maternal diabetes
Describe the functions of amniotic fluid
- Maintains constant body temperature for fetus: if mom were to overheat, there would not be a rapid change in the baby
- Musculoskeletal development: allows baby to have freedom of movement within the membranes; without it, growth would be restricted; it also cushions baby from outside trauma, so if mom were to fall or be in a vehicle accident, the amniotic fluid would serve as a barrier
- Barrier to infection: especially the membrane itself (amnion)
- Allows for fetal lung development: fluid is constantly moving in and out of lungs, therefore helping the lungs mature
- Cushions the umbilical cord: allows it to float freely, decreasing the chance of the cord knotting or becoming obstructed
- Contains fetal DNA (skin cells), so we can use it to do genetic tests
Amniocentesis - example of diagnostic test for chromosomal abnormalities
Describe the anatomy of the umbilical cord
2 arteries and 1 vein (AVA)
- Arteries: deoxygenated (umbilical arteries go away from the baby and carries deO2 blood and waste products)
- Vein: oxygenated (umbilical vein carries oxygen, nutrition, everything the baby’s needs)
The umbilical cord has a pulse, which can be felt pulsing after birth
Length of cord varies: some have thick cords, some have thin cords
- The bigger the baby, the thicker the cord and vice versa.
Sometimes the baby has two vessels in their cord;
- This is normally okay, but it can be associated with chromosomal abnormalities, so follow-up is done
What is Wharton’s jelly?
Connective tissue that prevents compression of the umbilical cord in utero - it is important that perfusion is kept in the cord
Protects the 3 vessels in the cord
Ensures continued nourishment to the fetus
What are some complications associated with the umbilical cord?
Nuchal cord: cord wrapped around the baby’s neck
- Fairly common
- Can result in stillborn baby
- What determines how bad it is is how tightly the cord is wrapped around the baby’s neck
- Nuchal x1 or nuchal x2 can be used to say how many times the cord is wrapped around the neck
- Decelerations may be seen on FHR
True Knot: the consequences depends on how tight the knot is
Describe the formation and structure of the placenta
Begins to form at implantation and is completely formed and functioning by end of 1st trimester.
It will take over the production of pregnancy hormones.
Will continue to grow and thicken throughout the pregnancy: the more surface area, the more nutrients it can take up.
By the end of the pregnancy, it will cover half of the inside of the uterus.
There is a very thin membrane that separates mom’s blood and fetal blood and keeps them from mixing;
The membrane allows for diffusion, good things (nutrients, O2) and bad things (medication, nicotine, drugs) can get through.
Maternal side: “lumpy and bumpy”; Fetal side: “shiny and smooth”
Describe the endocrine functions of the placenta
“Endocrine gland”: secretes hormones that will sustain the pregnancy and support the baby; prior to the placenta taking over this role (before end of 1st trimester), the corpus luteum performs this role -> this is cyst that is left when the egg is released.
1, hCG - The trophoblast secretes this right at implantation. It can be detected as early as 7-10 days. Its main role is to sustain or maintain the corpus luteum, which does not need to degenerate (as it does for period), because it secretes progesterone which a pregnancy NEEDS; IF this does not happen, miscarriage will occur
2. Progesterone - Maintains the pregnancy; maintains the endometrium; decreases contractility of the uterus; stimulates breast development and maternal metabolism
3. Estrogen - Involved with growth of the uterus, increasing blood flow to the uterus, preparing breast for lactation
Describe the metabolic functions of the placenta
- Respiration - The fetal lungs do not function in pregnancy. The placenta performs the function of respiration until birth occurs and baby takes first breath; the placenta diffuses oxygen from mom to baby and gets rid of carbon dioxide from baby to mom (works like our lungs).
- Nutrition - The placenta ensures that baby gets nutrition
- Excretion - The placenta gets rid of waste products; waste products will be excreted by MOM’s kidneys; Mom’s kidney function increases (GFR goes up)
- Storage - Protein, carbs, iron, and calcium can be stored in the placenta
Describe maternal blood pressure and placental function
Placental function depends on the maternal blood pressure supplying circulation.
By term: 10% of maternal cardiac output goes to the uterus
1. Hypertension - Vasoconstriction diminishes uterine blood flow. Vasoconstriction can also be caused by smoking and cocaine (cocaine also lead to small babies)
2. Hypotension/decreased cardiac output - Diminishes uterine blood flow
3. Supine hypotension -> “Vena Cava Syndrome” - When mom lies down, the pressure of the uterus compresses the inferior vena cava. Impeded venous return from lower extremities means that blood flow can’t get back to heart, lowering cardiac output. Mom will get dizzy, nauseated, and have sweaty palms. Usually seen in 3rd trimester. Best position for pregnant mom to lie: on her side (on her left side)
4. Time in labor that has an effect on perfusion; when uterus contracts, the blood flow is closed off temporarily; when contractions that are very prolonged and frequent, it negatively affects the baby
What are teratogens? When is the fetus most susceptible to teratogens?
Teratogens are substances or exposure that causes abnormal development (medications, drugs, smoking, viruses like MMR or chickenpox)
Embryonic phase: fetus is most susceptible to teratogens
Usually women find out they are pregnant after the period of greatest susceptible has passed (makes possibility of them using a teratogen during this period more likely)
What is viability?
Grandmultipara?
Stillbirth?
IUFD?
Abortion?
Viability: the capability of the fetus to survive outside of the uterus
Range acceptable to viability: 23-24 weeks (LMP) is when baby can survive outside the uterus
Grandmultipara: woman who has given birth 5 or more times
Stillbirth: a baby born dead after 20 weeks
Intrauterine Fetal Death (IUFD): a baby that has died in utero after 20 weeks
Abortion: any death before 20 weeks
Describe the development of the fetal circulatory system
Describe the 3 shunts
The heart is the first organ to function in developing embryo. It starts to beat 21 days (3 weeks) after conception (5 weeks after LMP)
FHR: 110-160 bpm
Because the fetal lungs are not functioning, there are 3 different shunts in fetal circulation that direct blood away from the lungs: (close within 24 hr after birth)
1. Ductus venosus - Vein that connects umbilical vein to the fetal inferior vena cava -> goes to right atrium
2, Foramen ovale - Opening between right and left atrium of the heart. Blood goes from right atrium to left atrium (pressures in pulmonary area is high, blood wants to take path of least resistance, so it goes to the left side and NOT the lungs)
3. Ductus arteriosus - Shunt that takes blood from pulmonary artery to the aorta, bypassing the lungs. Some blood still makes it to right ventricle (from right atrium), so the PDA redirects that blood.
Describe fetal development of the respiratory system
The last organ system to mature
Development begins in embryonic stage and continues through fetal life and childhood
Alveolar formation - continue to develop up to term; begin secreting surfactant near term, usually around 36-37 weeks
Pulmonary surfactant - holds alveoli open and keeps them from collapsing; can be detected in amniotic fluid. Amniocentesis can be used to detect surfactant
Respiratory movements - fetuses will do these movements when they are moving fluid in and out of their lungs; this contributes to the fluctuation of amniotic fluid. This movement prepares the baby for breathing, develops the chest wall muscles. “Practice breathing” - can be seen on ultrasound, it is a sign of fetal well-being.
Will see respiratory issues in babies born by C-section (going through the vaginal canal “pushes” out fluid)
Describe fetal development of the renal system
Fetal urine is a part of amniotic fluid volume
Fetus typically secretes urine by end of first 1st trimester
Kidney problems can be diagnosed in utero, it can be seen on ultrasound
Kidneys are fully developed at delivery; babies should pee within the first 24 hours
Describe fetal development of the neurologic system
Sensory awareness
By 12 weeks, babies can be seen “sucking” on thumb or fist on ultrasound
By 24 weeks, babies can hear
Later in pregnancy, baby will make purposeful movements
Babies will respond to mom’s voice or loud noises; “jump”
Babies will feel pain, at least by 23 weeks
Describe fetal developmental of the reproductive system
Sex differentiation - appearing distinctly male or female. This process starts during the 7th week
By end of 1st trimester, the baby is distinctly male or female
What is GTPAL?
How is it used in nursing?
G — the number of pregnancies including current pregnancy or GRAVIDA
T — the number of pregnancies that were delivered at TERM (37 weeks or >)
P — the number of pregnancies that were delivered PRETERM between 20 and 37 weeks (36 weeks and 6 days, even is baby was born dead)
A — the number of pregnancies ending in ABORTION (spontaneous or elective)
L — the number of children currently LIVING
Example- G T-P-A-L can be written as: G2 P1001
This patient is currently pregnant
This patient has had 1 term delivery, 0 preterm deliveries, 0 abortions, and has 1 living child
Describe hCG throughout pregnancy
What do high and low levels of hCG mean?
When is the best time to take a pregnancy test?
- It is the earliest biochemical marker for pregnancy.
- Production begins as early as day of implantation.
- Can be detected as early as 7 to 10 days after conception.
- There is an expected increase in hCG levels, it will double every other day throughout the 1st trimester (if they don’t, it could be an indicator of abnormal pregnancy)
- Towards the end of the 1st trimester, hCG will decline and level off
- Lower hCG = poor outcome such as ectopic pregnancy or miscarriage
- A higher hCG = multiples
- hCG is thought to cause all the nausea and vomiting during pregnancy; women carrying multiples tend to have more N/V. This could be why N/V tends to go away after 1st trimester
- Best time to take a pregnancy test = morning, when hCG is highest in urine
What does “presumptive” mean when it comes to signs of pregnancy?
What are the presumptive signs of pregnancy?
Presumptive: changes noticed by the woman but DO NOT confirm pregnancy (subjective)
Symptoms:
- Amenorrhea (missed period)
- Morning sickness
- Fatigue
- Breast changes
- Urinary frequency
- Quickening (mom’s perception of feeling baby movements)
What does “probable” mean when it comes to signs of pregnancy?
What are the probable signs of pregnancy?
Probable: changes observed by the examiner but don’t 100% confirm the pregnancy (objective findings by providers)
Signs and symptoms:
- Goodell’s sign: softening of the cervix (can be palpated in exam)
- Hegar’s sign: softening of the lower uterine segment (can be palpated in exam)
- Chadwick’s sign: bluish discoloration of the cervix that can be visualized in speculum exam
- Uterine Enlargement: found on internal palpation during exam
- Braxton Hicks contractions (fibroids can feel like this because they are firm)
- a positive Pregnancy test (not 100% positive)
What does “positive” mean when it comes to signs of pregnancy?
What are the positive signs of pregnancy?
Positive: changes only attributable to the presence of a fetus (100% confirms a pregnancy)
- Auscultate fetal heart tones (using a doppler)
- Visualization of fetus on ultrasound
- Fetal movements present (examiner palpating fetal movements)
Describe how the uterus changes in size throughout pregnancy
The uterus increases in size. This has to do with increase in blood flow to the uterus. After the 1st trimester, the growing fetus is what’s behind the increase in size
Describe how the position of the uterus changes throughout pregnancy. When does pregnancy show?
- The fundal height changes throughout pregnancy
- Lightening: the baby is getting its head engaged in the pelvis, getting ready to be born
- Pregnancy may “show” after the 14th week (LMP): when they “show” depends on whether it’s the woman’s first pregnancy or not; in first time moms, the muscles are tighter, they show early; weight also has to do with it (“body habitus”) skinny women will show a lot sooner, while women that are overweight, will “show” later.
- Displacement of abdominal organs - the uterus pushes everything to the side; bowel sounds are still heard, but may be heard in different places
- Hegar’s sign - softening of the lower uterine segment; can be assessed on a physical exam
Describe what fundal height should look like at certain weeks throughout the pregnancy
12 weeks: fundus can be palpated just above the symphysis pubis 16 weeks: fundus can be palpated halfway between symphysis pubis and umbilicus
20 weeks: fundus is at the umbilicus
21-36 weeks-fundal height in centimeters correlates with weeks gestation +/- 2 cm
36 weeks: fundus typically reaches its highest point at - women feel short of breath, diaphragm is being push
40 weeks: the fundal height drops - “lightening” - the baby is getting its head engaged in the pelvis; the baby “drops”, getting ready to be born
Describe the uterus’ contractility during pregnancy
Braxton Hicks contractions
- The uterus is a muscle; it starts to “warm up” contractions during the pregnancy; NOT the same as labor contractions; they are usually painless, and they are very irregular; they don’t increase in frequency like normal contractions, and they do not dilate the cervix.
These can begin in the 2nd trimester, but it varies depending on the woman
Describe uteroplacental blood flow during pregnancy
Uterine blood flow increases rapidly as the uterus increases in size in order to accommodate the rapidly growing placenta and fetus. Perfusion is important to the health of the pregnancy
Factors that decrease uterine blood flow include smoking, cocaine, hypertension, and lying flat on back.
Describe cervical changes during pregnancy
- Tissue changes from increased estrogen
- Mucus plug: an increase in vaginal discharge contributes to the mucus plug; the mucus plugs up the endocervical canal. This mucus has immunoglobulins that help prevent infection. As labor process begins, mom will pass the mucus plug
- Goodell’s sign: softening of the cervix (under hormonal influence)
- Chadwick’s sign: bluish discoloration of the cervix and vaginal walls (under hormonal influence)
Describe what quickening and when it usually occurs during pregnancy
Fetal movement or “flutter.”
Mom’s first perception of fetal movement
First movements feel like “butterflies”; also feels like peristalsis, like a gas bubble moving around.
When quickening happens vary woman to woman. It also depends on if it’s the first pregnancy or not
First time moms don’t know what it feels like; multiparous moms tend to feel quickening sooner than nulliparas moms
It also depends on body habitus: Obese women will feel quickening later in the pregnancy; a skinny mom that is multiparous could feel the baby moving a lot sooner
Range for when women should feel baby moving: 16-20 weeks LMP
Describe what ballotement is and when it is seen during pregnancy
Passive movement of the unengaged fetus
Prior to lightening, the baby is floating around in the amniotic fluid, this is when the baby can be balloted.
This is done during a pelvic exam; the examiner can feel the patient’s cervix and tap upwards on it, causing the fetus to rise. The fetus then sinks, and a gentle tap is felt on the finger.
This term is seen later in the pregnancy when examining to see if labor is going to begin -> if baby is “ballotable” then labor is not about to happen because baby is not engaged
Describe changes in the vagina and vulva during pregnancy
- Vaginal epithelium: vaginal mucosa thickens; the vaginal canal lengthens (hormonal influence); increase in vaginal discharge is normal and expected
- Chadwick’s sign: bluish discoloration of cervix and vagina
- Leukorrhea: thin, white or slightly gray mucous discharge with a faint odor; the increase in vaginal discharge is normal, but it should NOT have a foul odor.
- Vagina becomes more acidic during pregnancy, preventing bacterial infections. However, this makes the pregnant woman more prone to yeast infections
What are the positives and negatives of increased pelvic blood flow during pregnancy?
Positives: increase in sensation and sexual arousal
Negatives: women are more prone to hemorrhoids, varicose veins, edema (vulvar edema, external genitalia can get very swollen)
Describe how the breasts change throughout pregnancy
- The breast increase in size.
- Feeling of fullness, heightened sensitivity, tingling.
- Heaviness is normal.
- Nipples and areola; nipples will get more erect; nipples and areola will become more darkly pigmented.
- As blood flow to breasts increase and the vascularity increases, venous patterning will occur (increased appearance of veins)
- Striae gravidarum (pregnancy stretch marks) in areas that grow quickly, like the breasts
- Montgomery tubercles: Hypertrophy of the oil glands embedded in the areola, may be seen around the nipples. Little oil glands all over the areola will become more prominent in pregnancy because they are getting ready to secrete a substance that will lubricate the area for lactation.
- Colostrum
What is colostrum? When can it appear during pregnancy?
Very first “milk” produced early on in pregnancy
Creamy white to yellowish premilk fluid
Can be expressed from the nipples as early as 16 weeks
NOT the same as true lactation, which doesn’t begin till after birth
Usually produced 2nd trimester onward
What baby will get the first few days after birth; it is very nutrient dense for baby, produced in small amounts
Describe what happens to blood volume during pregnancy
Blood volume increases by 1500 mL (by 50%). This is a compensatory mechanism to accommodate the need to increase blood flow to the uterus while perfusing mom’s body and her vital organs.
An increase in blood volume is a protective mechanism. Women bleed in the postpartum period, some bleed excessively (postpartum hemorrhage); the body is bulking up blood volume to protect the woman in case she has excessive bleeding after giving birth.
Describe changes in blood composition during pregnancy
What does a normal H&H look like during pregnancy?
Increase in RBC production and plasma as blood volume increases. RBCs increases because the RBC’s oxygen-carrying capacity is needed during pregnancy.
The plasma component increases more than the RBC component, creating a diluting effect in the blood -> “hemodilution”
This hemodilution leads to a physiologic anemia, leading to a normal H&H drop in pregnancy.
Cutoff levels for hemoglobin in pregnancy:
1st trimester: 11
2nd trimester: 10.5
3rd trimester: 11
What does pregnancy do to circulation and coagulation times?
Tendency for blood clots because of increase in clotting factors for pregnant AND postpartum women (for about 6 weeks postpartum).
This is a protective mechanism for the bleeding that will occur after birth.
