Repro 1 Human Reproduction Flashcards
Theca Cells
works in a complimentary fashion with Granulosa Cells
►Pre-Ovulation
– Produce androstenedione (intermediate)
►Post-ovulation
– Produce Progesterone
Granulosa Cells
works in a complimentary fashion with Theca Cells
►Pre-Ovulation
– Imports Androstenedione from Theca Cells and uses it to produce Estradiol / Estrogen
►Post-ovulation:
– Produce Progesterone
Luteal Cells
Post-ovulation: theca and granulosa cells become LUTEAL cells
– Produce Estrogen & Progesterone
What are the steroid produces of the ovaries?
Androstenedione
Estrogen
Progesterone
Ovarian Cycle
endometrial cycle
►Ovarian Cycle: • Concerned with maturing an oocyte and its ovula=on. – follicular – ovulation – luteal
►Endometrial cycle • Concerned with crea=ng an environment that nurtures fertilized ovum. – proliferative – secretory – atretic
How many follicles does a baby girl have?
- From birth onwards, primary follicles undergo apoptosis
- At birth, ~2 million follicles
- By puberty, ~400 000 remain
- Average woman will ovulate 500 times
Elegant Strategy
…vs..
Siege Strategy
Elegant Strategy
–female cycle!
Siege Strategy
– for every heartbeat, males produce 1000 sperm
Early Ovarian Follicular Phase
Primary follicles respond to increasing FSH levels; developing theca and granulosa cells.
►LH promotes:
theca cells = androstenedione
►FSH promotes:
granulosa cells = estradiol
What does Estradiol promote?
Estradiol promotes: • granulosa cell proliferation • estrogen receptors • FSH receptors • LH receptors on granulosa cells
Late Ovarian Follicular Phase
- First follicle to develop LH receptors on granulosa cell becomes the DOMINANT FOLLICLE
- Dominant follicle responds to LH with ESTROGEN surge.
What does the Estrogen do?
- estrogen surge has a positive feedback effect on anterior pituitary
- results in LH spike prior to ovulation (IMPORTANT PIECE!)
- Dominant follicle inhibits sister follicles development (paracrine interaction).
Ovulatory Phase
►The surge of LH resulting from estrogens from the dominant follicle is critical for ovulation
►LH surge requires 2 days of elevated estrogen (200 pg/ml).
►LH triggers ovulation by:
• Neutrilized action of oocyte maturation inhibitor
• Induces the enzyme prostoglandin endoperoxidase synthase. Results in prostoglandin, thromboxane and leukotriene production.
• Contraction of follicular wall
Ovarian Luteal Phase
- Occurs post-ovulation
- In response to elevated LH, Granulosa cells and Theca cells form LUTEAL cells (corpus luteum)
- Luteal cells respond to LH by producing PROGESTERONE and estrogen.
- If oocyte (ovum) is not fertlized, luteal cells degenerate after ~12 days
Regulation of Ovarian Cycle
- Cycle is driven by LH and FSH.
- Initial increase in FSH recruits many follicles in both ovaries
- Steroid production begins in Theca cells under the influence of LH
- Granulosa cells on Dominant Follicle start to secrete ESTROGEN
- Increasing Estrogen levels POSITIVE FEEDBACK on ant. pit. Resulting in an LH surge (necessary for ovulation).
Endometrial Cycle
►Proliferation Phase
Cells lining the uterus divide in response to estradiol from granulosa cells, forming a layer of glands and blood vessels
►Secretory phase
After ovulation, cell division halts. Progesterone augments the blood supply and initiates the secretion of acid mucin
►Atretic phase
In the absence of a fertilised oocyte, progesterone decreases resulting in a loss of the uterine lining. This produces bleeding for 2-4 days. The next cycle begins on day 1 of bleeding and is marked by an increase in FSH.
When does progesterone go away?
Progesterone goes away in the absence of a fertilization event.
The cycle will begin again …
How long is the luteal phase?
14 days
If a woman has a menstrual cycle of 35 days, how long are the two phases?
Follicular Phases
• 21
• dynamic
Luteal Phase
• 14 days
• fixed!
Where does fertilization actually happen?
Fallopian Tube
How do sperm know what tube to go to?
Sperm have some “chemotactic” sensations that are able to assess which fallopian tube the egg is located. The swim towards that tube.
Follicular Phase
►Follicular phase
• Proliferative Endometrium (endometrial growth)
• Endometrial cell growth estrogen mediated
►Histology:
• Endometrial stroma thickens, glands elongate.
• No crowding
• <50% ratio glands to stroma
Luteal Phase
►Luteal phase
• Secretory endometrium (endometrial stabilization)
• Estrogen and progesterone mediated
►Histology:
• Endometrial stroma becomes loose and edematous.
• Blood vessels become thickened and twisted
• Endometrial glands tortuous
• >50% ratio glands to stroma
How long does sperm live in the female reproductive tract?
About 3 days.
Sperm hangs around for a while
When does basal temperature peak in women?
After Ovulation due to rising Progesterone
increases 0.5 Celsius
stays elevated from post-ovulation to start of menses
Surgery Options of Contraception
Women
…vs…
Men…
►WOMEN: Tubal Ligation
• Several methods availbale
• Older method was very invasive & risky and required General Anasthesia
►MEN: Vasectomy
Options for Contraception
►Natural Methods
►Tubal Ligation
►Barrier Methods
►Hormonal Contraception
“The Pill”
contains combo of estrogen & progesterone
Estrogen goes to Pituitary and causes Negative Feedback. Causes FSH levels to go down
Therefore, a dominant follicle will not be recruited!
Inhibits the production of a dominate follicle
What would happen if a woman just took Estrogen throughout the year as a birth control method?
Continuous proliferation of the lining
Abundant cervical mucus production
RESULT: could cause Endometrial Cancer
What is Progesterone added to the Birth Control?
Progestreone is added to BC becasue it allows:
• only supposed to have estrogen around in luteal phase
suppressess LH release
• thickens cervical mucus (sperm less likely to get though)
• affects the lining
What effect does the Pill have on the uterine lining?
THIN lining
Contraindications to Estrogen
►Blood Clots
►Hx of Breast Cancer
►Liver Disease
Progesterone ONLY pill
MOA?
►Primarily suppresses LH release – prevents ovulation (40%)
►Endometrium not receptive to ovum (decidualized bed with atrophic glands)
►Cervical mucus thick and impervious
►Reduced tubal peristalsis
IUD
►HORMONAL
• Progesterone keeps lining thin.
• Fertilized egg cannot implant.
►NON-HORMONAL
• Copper IUD
• toxic to sperm
• causes low-grade irritation to lining to prevent implantation
The pill is used for LOTS of different things.
What HUGE benefits does it have?
- Decreases risk of epithelial ovarian cancer
* Decrease risk of endometrial cancer
Emergency Contraception
2 different methods
►”Plan B”
• Progesterone blunts the LH surge → prevents ovulation
• thins lining → prevents implantation
• most often done
►Copper IUD
• prevents implantation
• not often done
Ectopic Pregnancy
What is it?
Occurs when a fertilized egg (embryo) grows outside the uterus
Most ectopic pregnancies happen in the fallopian tube (98%), but they can rarely occur in the ovary, abdomen or cervix
Dx - both:
• serum quantitative hCG
• transvaginal ultrasonography (TVUS).
Hx Taking for difficulty getting pregnant
►What are your periods like?
►Are your periods painful?
(dysmenorrhea - endometriosis)
►Do you know if you are ovulating?
(OTC ovulating sticks)
►How are you timing intercourse?
►Are your otherwise healthy?
►Any previous pregnancies?
►Erections & ejaculation?
Ovulating Sticks
(OTC - over the counter)
How do they work?
Measures LH surge
LH surge happens 36 hrs before ovulation occurs.
The urine kits measure LH levels and let patients know when ovulation is imminent.
When the stick is positive, couples are advised to have intercourse that night and the next night to optimize their chances.
Infertility
DDx
►Ovulation problems
(eg Polycystic Ovary Syndrome)
►Female Age
►Male Age (sperm count & mobility)
►Fallopian Tube / Uterine Factors
►Unexplained (1/3 of cases)
Uterine (endometrial Biopsy)
When do we do it?
Rule out the presence of pre-cancerous or cancerous tissue
NOT for infertility
Day 21 Progesterone
Serum progesterone levels rise after ovulation as it is produced by Corpus Luteum
We order it to confirm that the patient is ovulating
Should actually be called a Mid-Luteal Cycle. Should actually be done 7 days before menses.
Day 3 FSH
FSH stimulates the growth of the dominant follicle.
As women get older, it takes more and more FSH from the Ant Pit to stimualte the follicle to grow.
If Day 3 FSH level is high, that is a very significant warning with both ovulation and the receptivity of the uterine lining.
Hysterosalpingogram
X-Ray test
uses contrast which is injected into the uterus and then through the tubes
Confirms patency (openness) of tubes
CT Scan of Pelvis
Hysterosalpingogram is much better imaging tool to determine the status of a pt’s Fallopian tubes
TSH
Must order in pts who are struggling to obtain pregnancy.
Hypothyroidism can cause anovulation. Also, if is CRITICAL that a pregnant patient have a normal TSH!
Who struggles with infertility?
How common us infertility?
VERY COMMON!
►30-34
1/7 couples
►35-39
1/5 couples
►40-44
1/4 couples
Etiology in Couples with Infertility
Where are the problems?
►Male Sperm Problem
1/3
►Tubal/Pelvic
1/3
►Ovulation & Unexplained
1/3
However, what is the BIGGEST factor in infertility?
FEMALE AGE
Women are waiting longer and longer to have their first child. This is a societal problem.
Cumulative Fertility & Maternal Age
Don’t minimize a year. A year is a super long time when you want something really bad. Waiting can be emotionally exhausting!
►age 20-24
86% chance of conceiving within 1 yr
►age 25-29
78% chance of conceiving within 1 yr
►age 30-34
63% chance of conceiving within 1 yr
►age 35-39
52% chance of conceiving within 1 yr
What is the average age of menopause?
50-51
Why does pregnancy loss increase with maternal age
As women get older, it is harder to get pregnant because so many miscarriages occur.
The best eggs are used first. The ones that are used later have been arrested in Meiosis 1 for longer and accumulate for genetic abnormalities.
Chromosomal abnormalities can be present in older eggs. Most die. Trisomy 21 just happens to be a viable aneuploidy.
Couple presents with Infertility
When to investigate?
►When female is < 36 y/o
– After 12 MONTHS of trying.
►When female is 36 to 39 y/o
– After 6 MONTHS of trying.
►When female is >40
– IMMEDIATE investigations (these people do not have time)
What are the basic elements for Fertility
►Ovulation ►Ovarian Reserve ►Patent tubes / normal uterus ►Sperm ►Intercourse – MALE: erectile dysfunction – FEMALE:
What makes progesterone?
Corpus Luteum
We test for progesterone to prove that she ovulated
Ovarian Reserve Testing
How do we test?
We want to know if a woman is running low on eggs. If she is, then there is not much time left.
Period starts on day 1 of cycle
►DAY 3 FSH
<10 IU/I
low FSH means that it is not taking much FSH for the brain to make an egg
►Estradiol
– should be low because there is no dominant follicle yet
– use to confirm that test occurred on correct day (Day 3)
►Anti-Mullerian Hormone
– new test
What will FSH level look like in a post-menopausal woman?
> 40
Super high because the brain is having to push super hard to push out an egg. No longer any negative feedback. The ovaries no longer respond. There is no estrogen. The brain is hollering at the ovaries, but nothing happens anymore
What are reasons for which a female might not ovulate?
►PCOS
►Hypothalamic Hypogonadism
– Ovaries are just fine, this is a brain problem. The brain shuts down LH & FSH as it does not want to ovulate during stressful times
►Hypothyroidism
►Hyperprolactinemia
►Premature Ovarian Failure
How do we establish tubal patency?
Hysterosalpingogram
Must push dye through Fallopian Tubes in order to visualize them. U/S will not cut it.