Flashcards in 7. Normal Pregnancy Deck (105):
Average gestation (days)
Average gestation from LMP
• Calendar months
• Lunar months
• 280 days
• 9 calendar months
• 10 lunar months
• 40 weeks
Fertilization: The union of a single egg and sperm. Marks the beginning of pregnancy
Reproductive / germ cells -- give rise to the sperm and egg
(When does ovulation occur?)
Release of egg (the ovum)
(five days before or after day 14)
Introduction of sperm into female reproductive tract
Union of the gametes
Into the uterus
What is a "Graafian Folical? What hormone does it produce?
• A small sac embedded in the ovary that encloses the ovum.
• Produces estrogen
Role of estrogen in becoming pregnant
• Prepares the endometrium to receive a fertilized egg
Define "Primordial / Primitive Follicles"
Undeveloped egg cell
Changes associated with follicular ripening (4)
• Moves to the surface of the ovary and forms a projection
• Follicle and ovum within become larger
• Follicular wall becomes thicker,
• Fluid collects in the follicle and surrounds the egg
What happens when the graafian follicle becomes fully mature?
Graafian follicle brakes open and releases the ovum, which passes into the uterine tubes.
What 2 hormones cause the ovum to mature?
From where is ovum released?
When does this occur?
• Ovum released from ovarian follicles
• Occurs about 14 days before a woman’s next period would begin
• What is it
• Hormones (2)
• The remaining cells of the follicle after ovulation.
• Sticks around for 12-14 days
• Secretes estrogen, progestrone
• Prepares endometrium for a fertilized ovum
What hormone does the ovum secrete if it becomes fertilized?
Secretes chorionic gonadotropin
What happens if the ovum is not fertilized?
• Hormonal changes (4)
• FSH and LH fall to low levels; corpus luteum regresses
• Subsequent decline of estrogen and progesterone.
How is the mature ovum transported through the fallopian tube? (2)
• The musculature of the fallopian tube
• The Cillia
How long does it take the ovum to travel from the ovary to the uterus?
Where does fertilization ideally take place?
In the distal 1/3 of the fallopian tube (AKA the Ampulla), which is close to the ovary.
How many sperm are there in an ejaculation?
35,000 to 2 million sperm
The sperm are suspended in what?
2-5 mL of seminal fluid
Seminal fluid: Function
Nourishment and protection of the sperm from the acidic environment of the vagina
What is mitotic Cellular Replication? (Cleavage)
The fertilized egg divides rapidly with no increase in size and smaller cells (blastomeres) are formed with each division
Rapidly dividing cells that do not increase in size, formed with each division
When the number of blastomeres reaches 16 -- a solid ball of cells
Characteristics of the morula
• Surrounded by a protective coating called the zona
• Secretes a fluid that forms a blastocyst
A sac of cells with an inner cell mass
Part of the cell mass that becomes the PLACENTA
Part of the cell mass that becomes the EMBRYO
Protective coating that surrounds the morula, then degenerates during implantation
The ________ cells displace the _________ cells at the implantation site
During implantation, the _______ embeds in the _______.
What happens 6-10 days after conception?
The trophoblast secretes enzymes that enable it to burrow into the endometrium until the entire blastocyst is covered.
When is the pre-embryonic phase? What four things occur during this phase?
Conception to day 14
• Cellular replication
• Blastocyst formation
• Yolk sac formation
• Differentiation begins
Three layers of embryonic disc, and the system that each frms
• Ectoderm: Upper layer of embryonic disk. CNS
• Mesoderm: Middle layer
Meso- middle – MUSCLES!
• Endoderm: Lower Layer
Digestive tract, respiratory tract
Four hormones produced by the placenta
• Human Chorionic Gonadotropin (hCG)
• Human Placental Lactogen (hPL)
• Progesterone (P)
• Estrogen (EE)
Human chorionic gonadotropin (hCG) function
Hormone that preserves the function of the corpus luteum to maintain early pregnancy
Human Placental Lactogen (HPL)
o Stimulates maternal metabolism to supply needed nutrients (Similar to a growth hormone)
o Increases the resistance to insulin
o Facilitates glucose transport across placental membrane
o Stimulates breast development to prepare for lactation
Progesterone (P) - 2 roles
Stimulates maternal metabolism and development of breast alveoli
Estrogen (EE) - 2 roles
o Stimulates uterine growth and uteroplacental blood flow
o Causes proliferation of glandular breast tissue
Metabolic functions of the placenta (3)
• Respiration (Oxygen diffuses from the maternal blood across)
• Storage / Nutrition
The main exchange of material between the mother and the embryo or fetus occurs through _____
The branch villi in the placenta
The decidua (def)
Endometrium becomes the decidua, which lines the uterus during pregnancy is and is shed with the afterbirth
What are scattered over the entire surface of the decidua?
Fetal hemoglobin compared to maternal hemoglobin (2)
o Fetal hemoglobin carries 20-30% more oxygen than maternal hemoglobin
o Fetal hemoglobin concentration is 50% greater than that of maternal
Nutrients stored in the placenta (4)
How are nutrients passed to fetus?
By facilitated and active transport in the placenta
How are water and electrolytes passed to the fetus?
By passive diffusion
Intrauterine membranes (2)
• Chorion: Outer cell membrane
• Amnion: Inner cell membrane
Role of amniotic fluid
• Helps maintain a constant body temp
Umbilical cord roles (2)
• Arteries: Carry deoxygenated blood and waste to chorionic villi
• Vein: Returns oxygenated blood and nutrients to fetus
Physiologic changes of the uterus during pregnancy (3)
o Enlarges and thickens
o Braxton Hicks contractions (painless)
o Softening of the lower uterine segment.
Four physiological changes that occur to the cervix
• Mucus plug
• Changes position with impending labor
• What is the goodell sign?
• When does it occur?
• Cervix can be compressed, feels a little softer.
• Occurs after the 6th week
How is the mucus plug formed? What is its purpose?
• Forms when copious mucoid vaginal fluid fills the endocervical canal
• Due to increased estrogen
How does the cervical position change with impending labor?
Moves posterior to anterior before delivery
Physiological changes of the vagina (3)
o Bluish color (“Chadwick’s Sign”)
o External structures may be enlarged
Physiological changes of the breasts (6)
• Increased size
• Superficial veins prominent
• Leakage of colostrum
What is leukorrhea? What causes it?
• White or slightly gray mucoid discharge with a faint musty odor.
• In response to cervical by estrogen and progesterone
What causes Chadwick's sign?
• Occurs due to an increase in vascularity
Why may external vaginal structures become enlarged?
• Reason: Hormones that prepare the vagina stretching during labor and birth causes the smooth muscles to hypertrophy
Discomforts of pregnancy (13)
(Don't memorize; just review)
• Breast changes
• Urinary frequency
• Varicose veins
• Leg cramps
• Round ligament pain
• Braxton Hicks
How does blood volume change during pregnancy?
How does HR change during pregnancy?
Increases 10bpm (due to increased blood volume)
How do WBCs change during pregnancy?
Increase to an average of 15,000
How does cardiac output change during pregnancy?
How does blood pressure change during pregnancy?
• Remains the same in the 1st and 3rd trimesters
• Lowers by 10-15 mmhg in 2nd trimester
How does oxygen consumption change in pregnancy?
Increases in the second half of pregnancy
How does body's response for CO2 change in pregnancy
How does the respiratory rate change in pregnancy?
Why does respiratory congestion occur in pregnancy?
Increased vascularity of the upper respiratory tract
How does BMR change during pregnancy?
Why does the BMR increase during pregnancy?
• Increased maternal cardiac work due to Uterine-fetal-placental unit
Changes in the renal system during pregnancy (4)
• Urinary frequency
• GFR increases 50%
• Dilation of renal pelvis and ureters increases (slows urine)
• Water retention
What clinical implications does dilation of the renal pelvis have during pregnancy?
• Allows a larger amount of urine to be held in the ureters
• Stagnant urine → Susceptibility to UTIs
Changes in the integumentary system during pregnancy (5)
• Increased pigmentaiton (aereola, nipples, vulva)
• Lina negra
• Stretch marks
• Oily skin, acne
GI changes during pregnancy (8)
• Appetite changes
• Nausea and vomiting
• Gums swell and bleed
• Pytalism (Increased drooling)
GI Discomforts of pregnancy - timing
• 1st trimester
• 3rd trimester
• N/V: 1st trimester
• Constipation: 3rd trimester
Musculoskeletal changes during pregnancy (3)
• Pelvic joints relax
• Change in posture and center of gravity
• Exaggerated lumbosacral curve
Psychological changes of pregnancy: first trimester (3)
• Accepts biological fact of pregnancy
• Body image changes
Psychological changes of pregnancy: second trimester (2)
• Acceptance of reality of child
Psychological changes of pregnancy: Third trimester (2)
• Prepare for birth and parenting
Three phases of "Paternal" Adaptation
1) The announcement phase
• Accept biological fact of pregnancy
• Ambivalence is common
2) The moratorium phase
• Adjust to the reality of pregnancy
3) The focusing phase
• Active involvement with pregnancy and relationship with unborn child
Maternal weight gain: First trimester
3-4 lbs weight gain (total)
Maternal weight gain: 2nd and 3rd trimester
1 lb per week
What four nutrients should a mother increase during pregnancy?
Increase during pregnancy: Kcals
+300 per day
Increase during pregnancy: Protein
+60g per day
Increase during pregnancy: Iron
- Ferrous sulfate
- Elemental: +30-60 per day
- Ferrous sulfate: +350 mg per day
Patient teaching re: iron supplements
• Vitamin C increases absorption
• Milk, bran and tea decrease absorption
• Take between meals
• Increase fiber
Pregnancy requirements -- calcium
2500 mg of calcium per day.
** At least 3 servings of milk, cheese or yogurt.
Normal weight gain. 10 pounds by...
20 weeks gestation
Total pregnancy weight gain for "normal" BMI (19.8-26)
Total pregnancy weight gain for "obese" BMI (>29)
3 cautions with pregnancy exercise
• Avoid impact sports
• Pain, SOB, dizziness → STOP
What is physiologic anemia of pregnancy?
Occurs because the increase in blood volume is greater than the increase in RBCs.
Iron deficiency anemia
- Causes (2)
- Result (1)
• Inadequate intake
• Poor absorption
• Results in decreased O2 carrying capacity of the blood
Diagnostic criteria for Iron Deficiency anemia (2)
• HCT <10.5-11
Treatment for anemia
• Iron supplementation is often prescribed for all pregnant women by the second trimester to prevent anemia
6 risks of anemia
• Poorly prepared to tolerate PPH
• Cardiac failure during labor
• PP infections
• Poor wound healing
• Preterm labor
• Neonatal IDA
Hyperemesis Gravidarum (def)
Excessive n/v that persists past the first trimester.
Hyperemesis Gravidarium: Diagnostic criteria
5% weight loss of the pre-pregnancy weight