Lecture 15: Fertilization and Pregnancy Flashcards
List 3 tests for pregnancy
1) Urine HCG
2) Serum HCG (qualitative, quantitative)
3) Transvaginal ultrasound
Describe Naegele’s Rule for Dating Pregnancy
-Onset of last menses
-Move back 3 months
-Then 7 days forward
-One year forward
What are the assumptions of Naegele’s rule for dating pregnancy?
28-day cycles with 14-day follicular phase and woman knows her LMP
Is Naegele’s rule for dating pregnancy accurate?
No; incredibly inaccurate- there are apps for this these days
1) How long does pregnancy last from gestation and from LMP?
2) Uterus expands more than ______ times in pregnancy
3) How much does the fetus develop in pregnancy?
4) What happen to the breasts in pregnancy?
1) Lasts about 38 weeks from conception (40 weeks from LMP)
2) 20
3) Fetus develops to the point of being able to leave maternal life support
4) Breasts enlarge and develop ability to produce milk
Define fertilization
Fusion of male and female gametes
What two things in the genital tract transport the gametes toward each other?
Cilia and Smooth Muscle
The _________________is the site of fertilization
Ampulla
1) Males produce _______mL of semen
2) _____________ million sperm per mL
3) Only _____________ sperm reach the ampulla
1) 2-6
2) 20-30
3) 50-100
1) Fertilization must occur within how many hours after ovulation?
2) Where does it normally occur?
3) How long can sperm live?
1) 12-24 hours
2) In ampulla,upper third of the oviduct
3) Up to 5 days
[Fertilization]
1) Define capacitation
2) What triggers it?
1) Final maturation of sperm
2) Acidic environment removes glycoproteins
[Fertilization]
1) Sperm binds to what?
2) What ion does this increase? What does this lead to?
1) Zona Pellucida
2) Ca2+; acrosomal reaction
(acrosome fuses w. plasma membrane)
[Fertilization]
1) What does Ca2+ trigger the acrosome to fuse with?
2) What does this trigger? What physical change does this cause?
1) Acrosome fuses with the plasma membrane
2) A cortical reaction; egg becomes hardened to other sperm
[Implantation]:
Zygote undergoes __[mitotic/ miotic]__ cell divisions, forming a ball of cells called a ________, and then a ____________ capable of implantation on the _____metrium
mitotic; morula; blastocyst; endometrium.
[Implantation]
1) What happens to a blastocyst’s surface after it’s formed?
2) What happens to the endometrium simultaneously? How?
1) Becomes sticky
2) Becomes adhesive; formation of CAMs [cell adhesion molecules]
[Implantation]
1) What do the cells in the blastocyst do [after blastocyst and endometrium become sticky/ adhesive]?
2) How do they do this?
3) Why/ what does this accomplish?
1) Digest pathways to endometrial cells.
2) Cords of trophoblastic cells dig into the endometrium, where they cont. to digest uterine cells.
3) Carves a hole to make space and provide fuel for developing embryo.
1) Following implantation of the blastocyst in the uterine wall, the _______________ forms.
2) What form and fill with blood to eventually develop into this structure?
1) placenta
2) Lacunae [eventually become a placenta]
What else continues while the placenta forms in the uterine wall?
[hint: this process is one word]
Differentiation
What 2 tissues of the endometrium develops into the placenta?
Trophoblastic and decidual
[Placenta development]
What layer of the endometrium is 2 layers thick and becomes called the chorion?
Trophoblastic layer
[Placenta development]
What layer of the chorion continues to expand? What does this eventually erode, and what does this cause?
Trophoblastic layer; maternal capillary walls, leaking maternal blood to fill the cavities
1) A system of what two interlocking tissues makes up the placenta?
2) True or false: All exchanges take place across this extremely thin barrier.
3) What systems of the mother does this allow the fetus to use?
1) Maternal (decidual) and fetal (chorionic) tissue
2) True
3) Respiratory, digestive, and renal
List 2 hormones made by the placenta and describe when each begins to rise and for how long
1) hCG: human chorionic gonadotropin
-detectable 6-8 days post-fertilization [doubles every 2-3 d until 15 wks]
2) hPL: Human placental lactogen
-rises in wk 3 [until term]
1) What hormone extends life of the corpus luteum?
2) What does this also stimulate?
3) When is this hormone detectible?
4) When does it increase and at what rate?
1) hCG
2) luteal steroidogenesis
3) 6-8 days after fertilization
4) Every 2-3 days until about 15 weeks
1) What hormone is similar to GH and PRL?
2) When does it rise in pregnancy?
3) What does it regulate? By promoting what?
4) What condition can it lead to?
1) hPL
2) During the 3rd week until term
3) Fuel availability by promoting maternal insulin resistance
4) Gestational diabetes
What else does the placenta make?
Peptides and some other hormones
What exchanges does the placenta facilitate?
Exchng. of gases, nutrients, and other factors.
Give examples of exchanges between the mother and fetus and list the direction of transfer.
1) To fetus: O2, water, electrolytes, carbs, lipids, amino acids, vitamins, hormones, antibodies, drugs (some), viruses (most)
2) To mother: CO2, water, urea, waste products, hormones
[Placental exchange:]
1) What produces progesterone and estrogen during pregnancy?
2) What is the primary source until 8 weeks?
1) Maternal-Placental-Fetal Unit
2) Corpus luteum
[Placental exchange:]
What does estrogen increase and enhance in both the mother and fetus?
Increases size of uterus and blood flow, enhance fetal organ development, increase breast tissue
[Placental exchange:]
1) What does progesterone maintain? What does it inhibit?
2) What does it suppress?
1) Uterus; myometrial contractions
2) Material immunologic responses to fetal antigens
1) Describe the Maternal-Placental-Fetal Unit; what hormone does placental trophoblast synthesize? From what?
2) This hormone produced by the placenta enters the ______________ circulation.
1) Progesterone; maternal LDL cholesterol.
2) maternal
1) Progesterone produced by the placenta enters the ____________ circulation.
2) Some gets converted to ____________.
3) What effect does this have?
1) maternal
2) DHEAS
3) Increases water solubility and aids in transportation
1) What brings about changes that induce maternal adaptation in pregnancy?
2) There’s a _____% increase in plasma volume
3) What hormone stimulates the renin-angiotensin system in pregnancy?
1) Rising levels of estrogens, progesterone, hPL and other placental hormones
2) 50%
3) Estrogen
Estrogen stimulates the renin-angiotensin system to raise _____________ levels and promote ____________ reabsorption, thus, water _____________.
aldosterone; sodium; retention
What are the only two physiologic factors discussed to decrease during pregnancy?
Peripheral resistance and functional residual capacity
Maternal Adaptation in Pregnancy:
1) There’s a ____% increase in red cell volume
2) What two things stimulate erythropoiesis?
3) Why is this increase needed? (2 reasons)
4) What type of anemia can this result in?
1) 30%
2) hPL & progesterone
3) Help meet demand of increased vasculature in uterus and blood loss during birth
4) Iron deficiency anemia
[Maternal Adaptation]:
1) There’s a physiological __[increase/ decrease]__ in systemic BP during pregnancy.
2) This should not to be mistaken for ____________.
1) decrease
2) hypotension
1) What type of compression can potentially explain low BP in pregnancy if pt is experiencing symptoms? When and in what position?
2) Why does it happen?
3) List the chain of events
1) IVC compression; > 20 weeks gestation; supine position
2) Growing uterus is compressing on IVC and/or aorta can threaten perfusion to body and/or placenta
3) Less venous return > less CO > BP falls > dizziness, lightheadedness, headache, presyncope > syncope
1) Pregnancy increases risk of blood clots (venous thrombo-embolism/VTE) by how many times?
2) Women are at risk for blood clots during what 3 times?
1) 5x
2) Pregnancy, childbirth, and 3 months after delivery
During pregnancy, a woman’s blood clots more easily to lessen blood loss during labor and delivery and protect from hemorrhage; how?
Coagulability increases:
1) Increase in clotting factors (7, 8, 9, 10) and fibrinogen.
2) Fibrinolytic activity decreases simultaneously.
1) Pregnant women may also experience less blood flow to legs later during pregnancy; why?
2) What serious condition can this lead to? Why?
1) Blood vessels within pelvis are compressed by growing uterus
2) Less flow, more chance for clots = DVT
Pregnant women may be less active than normal (bed rest, etc.) which predisposes a person to _________________
blood clots
1) What two things abt pregnancy alter pulmonary funct.?
2) What sensitivity does the rise in progesterone [in pregnancy] enhance?
2B) What does this increase?
1) Progesterone & the enlarging uterus
2) Brain respiratory center to carbon dioxide
2B) Tidal volume
List what happens to these in pregnancy:
1) Airway tone
2) Minute ventilation
3) PCO2
4) Arterial PO2
5) pH
[all due to progesterone and enlarging uterus]
1) Relaxes; bronchodilation
2) Increases: 30%
3) Decrease
4) Increase
5) Slight respiratory alkalosis
1) As uterus enlarges the diaphragm is elevated by how much?
2) What does this cause?
3) What two vitals does this reduce?
1) 4-5 cm
2) Early closure of smaller airways
3) Functional residual capacity and expiratory reserve volume (FRC & ERV)
1) Increased renal blood flow results in decreases in what 3 things that can be found in the plasma?
2) _________ GFR (aprx 50%) results in some glucosuria in more than ______ of pregnant women
3) What does this glucosuria increase risk of?
1) Plasma creatinine, BUN, and osmolality.
2) Greater; half.
3) UTIs
1) Why is there increased renal blood flow in pregnancy?
2) What is creatine normally? What abt in pregnancy?
1) Progesterone-mediated reduction in renal vascular resistance
2) Normally, 0.5 – 1.0
-During pregnancy = 0.4 – 0.8
1) Nausea and vomiting (morning sickness) in pregnancy are also called what?
2) Increased fluid in veins, some of which are in rectum, are called what?
1) Hyperemesis gravidarum
2) Hemorrhoids
Why does constipation occur in pregnancy? Explain
Progesterone = vasodilator
-Decreases transmit time in intestines > colonic relaxation > hard stools > constipation
1) GERD (heartburn) occurs in pregnancy bc of what two factors?
2) What lifestyle changes can help?
3) What severe GI condition can occur in pregnancy?
1) LES (lower esophageal sphincter) relaxation + compression of stomach by gravid uterus = reflux
2) Avoid caffeine, spicy foods, nicotine
-TUMS are safe during pregnancy
3) Gallbladder disease
Endocrine function and maternal metabolism change to support fetal growth by increasing what 4 hormones?
1) PRL
2) Cortisol
3) CRH
4) Insulin
Of the 4 hormones discussed that increase in pregnancy:
1) Which involves breastfeeding?
2) Which is a stimulant for labor?
3) Which maintain blood sugar levels (risk of gestational DM)?
4) Which contributes to fetal lung development?
5) Which cause stretch marks and contr. to insulin resistance?
1) Prolactin; “pro-lactation”
2) Corticotropin releasing hormone (CRH)
3) Insulin
4) Cortisol
5) Cortisol
List 2 types of hyperpigmentation in pregnancy
1) Melasma
2) Linea nigra
List 2 other pigmentation changes in pregnancy
1) Palmar erythema
(aka spider telangiectasia)
2) Spider angioma
1) What is also known as the “mask of pregnancy”?
2) Darkening of the skin over linea alba is called _______________.
3) Define linea alba
1) Melasma
2) linea nigra
3) Band of white, fibrous tissue running down from sternum to pelvis
Latin – alba “white”; nigra “black”
What is also known as spider telangiectasia?
Palmar erythema
1) Rh incompatibility occurs when mother’s blood type is Rh ________ and her fetus’ blood type is Rh __________.
2) Explain what happens when this occurs and what health conditions it causes
1) negative; positive
2) Antibodies from an Rh-negative mother (anti-RH+ antibodies) may enter the blood stream of her unborn, Rh+ infant, damaging the infant’s RBCs causing anemia-related health conditions
1) Rh immune globulin, also known as RhoGAM, given routinely at _______ weeks when Rh incompatibility exists (Rh- negative).
2) When should it be given if a woman experiences vaginal bleeding?
1) 28 weeks
2) 1st trimester
When the mammary gland develops in pregnancy:
1) What is the primary hormone that promotes mammary growth?
2) What is maintenance of milk production?
1) Prolactin
2) Galactopoiesis
__________ activates milk ejection; aka the “let down” reflex
Oxytocin
When does the mammary gland differentiate, mature, and proliferate?
1) Differentiates: in utero
2) Matures: in puberty
3) Proliferates: during pregnancy
When the lactiferous ducts proliferate [in pregnancy]:
1) ___________________ cells differentiate into secretory cells under stimulation by the pregnancy hormones
2) What cells contract when stimulated to force milk into the ducts?
1) Alveolar cells
2) Myoepithelial cells
1) Lactogenesis begins during what month of gestation?
2) What is the only thing produced @ onset of lactogenesis?
3) What is this higher in? (3 things). What immunoglobin does it contain?
1) 5th month
2) Colostrum
3) Protein, sodium and chloride; IgA
1) Parturition (birth) is on average _________ days+/- 14 days from fertilization
2) What hormone keeps the uterus inactive? What expression is reduced?
3) Is this reduction/ block overridden or not?
1) 270
2) Progesterone; estrogen receptors expression (progesterone block)
3) Fetal growth stimulates more receptors, overriding block
[Parturition (birth):]
Prostaglandins produced by uterine cells stimulate _______________________ cells
uterine smooth muscle
Parturition requires dilation of the ______________ to accommodate passage of the fetus and Strong contractions of the ___________________ to expel the fetus
cervical canal; uterine myometrium
Placental _______________ reaches a peak which prepares uterus and cervix for labor and delivery
estrogen
Placental estrogen reaches a peak which prepares uterus and cervix for labor and delivery; this includes:
1) ___________ inserted into gap junctions allow the uterine smooth muscles cells to contract as a single unit
2) Increased concentration of myometrial _____________ receptors; ____________ ultimately initiates labor
3) Local prostaglandins degrade local __________ fibers and also increase responsiveness to ___________.
1) Connexons
2) oxytocin; oxytocin
3) collagen; oxytocin
What ultimately initiates labor?
Oxytocin
Parturition’s positive feedback cycle of oxytocin (pre-delivery):
1) What first triggers this cycle?
2) What happens when uterine contractions become more powerful?
1) Pressure of the fetus against the cervix triggers oxytocin from posterior pituitary
2) More oxytocin is released
Parturition’s positive feedback cycle of oxytocin (post- delivery):
1) What causes the secession of this cycle? Why?
2) What two hormones are gone?
3) What hormone inhibitory effect on prolactin is then withdrawn? What does this do?
1) Baby and placenta are delivered,pressure against cervix ceases
2) Placental estrogen and progesterone
3) Estrogen; initiates lactation
