Flashcards in Repro 7.2 contraception and infertility Deck (73):
What is the effect of low levels of oestrogen?
Negative feedback onto the hypothalamus and the anterior pituatory, reduces levels of LH.
What is the effect of high levels of oestrogen at ovulation?
There's no progesterone so oestrogen leads to positive feedback on the hypothalamus and the pituatory, leading to the LH surge.
What is the effect of high/moderate doses of progesterone?
Promote the negative effects of oestrogen, leading to no LH surge, therefore no ovulation.
What is the effect of low levels of progesterone?
wont inhibit the LH surge, but does thicken the cervical mucus, making the environement hostile towards sperm.
What are some common methods of contraception?
(What part of the reproductive tract are you targetting?
-prevention of ovulation
-inhibition of sperm transport
-inhibition of implantation
Describe natural methods of contraception.
getting to know your cycle so you know when you'll be ovulating, then not having intercourse just before/during that time.
Using your temperature, which increases slightly when progesterone is high, to montior the point of your cycle.
After childbirth, breastfeeding leads to increased prolactin release, which inhibits GnRH release, so you do not ovulate.
What are some advantages of natural methods of contraception?
dont have to use hormones/chemicals
What are some disadvantages of natural methods of contraception?
Rely on really regular menstruation, which cant always be predictable.
no as effective, eg when stressed, or if you lose weight your cycles may not follow thier regular pattern.
Describe barrier contraception.
Phyical barrier stopping sperm from getting into the female reproductive tract, eg condom. Diaphragm.
Diaphragm may alos be sprayed with spermicide before fitting, so there is a chemical barrier to stop sperm too.
What are some advantages of barrier contraception?
-protects against STIs
-No use of hormones
-can be inserted at any point before intercourse.
What are some disadvantages of barrier contraception?
-Male condoms- some allergic to latex, can tear/come off.
-female condoms- not widely available.
-diaphragm- can displace. spermicide may cause local reactions.
What are some contraceptive methods of preventing ovulation?
Describe the COCP
Uses high levels of progestogen and oestrogen to inhibit ovulation.
The progestogen also has secondary effects of thickening cervical mucus, and reducing the endometrial receptivity so implantation is less likely.
What are some advantages of COCP?
-other uses for skin, releiving menstrual disorders.
-regulates menstrual cycle really well
-reduces the risk of ovarian cancer and cysts.
What are some disadvantages of the COCP?
-have to remember to take it at the same time every day
-can get breakthrough bleeding, breast tenderness, mood swings etc.
-Increases the risk of thromboembolism, cant be used for people who get migranes, etc.
-many contraindications. (PRevious MI, TIA, etc)
What is the synthetic progesterone called?
What is the progesterone depot?
Intramuscular injection into the buttocks to inhibit ovulation via high levels of prgestegon.
(also thickens cervical mucus and decreases receptivity of the endometrium).
What are some advantages of the progesterone depot?
-it lasts 3 months (Can forget about it after that)-convenient
-can relieve menstrual disorders.
What are some disadvantages of the progesterone depot?
-doesnt protect agaisnt STIs
-can cause irregular altered bleeding.
-after use, fertility can take up to 1 year to return (Not easily reversible)
-small loss of mineral bone density
What is the progesterone implant?
A small plastic rod which contains progesterone and is inserted under the skin of the inner arm, which releases high levels of progesterone, inhibiting ovulation.
(thickened cervical mucus, decreases endometrial receptivity)
What are some advantages of the progesterone implant?
-long duration of action (3 years)
-can be used to relieve menstrual disorders.
What are some disadvantages of the progesterone implant?
-requires a small procedure to fit and remove it.
-can cause irregular bleeding
-can cause local adverse effects.
What is the main contraception that causes inhibition of sperm transport?
The progesterone only pill.
How does the progesterone only pill work?
Low levels of progesterone which causes thickening of the cervical mucus, preventing the transport of sperm. (Ovulation still occurs)
What are some advantages of the POP?
-can be used when COCP cannot.
What are some disadvantages of the POP?
-Can cause irregular bleeding
-Must be taken at the same time every day (within 3 hours or else not effective)
What form of contraception inhibits the implantation of the zygote?
what are the 2 types of contraceptive coil?
-Intrauterine system (IUS)
-Intrauterine device (IUD)
How does the intrauterine system work?
it contains progestegon which decreases endometrial receptivity, meaning a conceptus cannot implant into the uterus.
Endometrial proliferation is reduced.
Also thickens cervical mucus as a secondary action.
Ovulation is not inhibited.
What are some complications of the Intrauterine system?
-long duration of action
-can relieve menstrual disorders.
What are some disadvantages of the intrauterine system?
-Insertion can be unpleasant
-Can become displaced/expelled.
-can cause menstrual irregularity
-risk of uterine perforation
How does the intrauterine device work?
a copper coil, copper is a natural spermicide and toxic to the ovum.
It prevents fertilisation.
Secondary actions- copper prevents endometrial proliferation so implantation cannot occur.
What are some advantages of hte intrauterine device?
-long duration of action
-can be used as an emergency contraception up to 5 days after intercourse.
What are some disadvantages of the intrauterine device?
-Insertion may be unpleasant
-Can make periods heavier/ longer.
-risk of uterine perforation.
-Can cause PID-->ectopic pregnancy
How long does an intrauterine system last compared to an intrauterine device?
IUS- 3-5 years
What are the forms of sterilisation and what do they entail?
male- vasectomy, interruption of the vas deferens so sperm cannot travel. Done via local anaesthetic.
female-tubal ligation/clipping- prevents the release of the ovum, so fertiliasation cannot occur. done under local/general anaesthetic.
What must you confirm after a vasectomy?
After 6 weeks you must take a sample of the mans semen and make sure there is no sperm.
What are some advantages of sterilisation as a contraceptive method?
-no hormonal side effects
What are some disadvantages of sterilisation as a contraceptive method?
-Dont always work (female failure rate is 2-5/1000)
-Shouldnt be done if in any doubt of having future chidlren.
-dont protect against STIs.
'failure of conception in a couple having regular unprotected intercourse (2+ times a week) for one year'
What is the difference between primary and secondary infertility?
primary- you have never been pregnant before
secondary- previous pregnancy
How common is infertility?
Aroun 1 in 7 couples will have difficulty concieving
What should you ask about a female who is having trouble falling pregnant?
-How long has she been trying
-length of her cycle, predictability, age of menarche
-any surgery affecting tubes/pelvis
-any previous STIs?
What should you ask a man who is having difficulty concieving?
-previous surgery to testes.
What examination should you do on patients concerned about infertility?
-BMI (underweight, may not be ovulating. If overweight could be imbalance between hormones)
-signs of secondary sexual characteristics
What are you looking for when doing a pelvic examination regarding infertility?
any structural abnormalities, eg uterus may be in the wrong position. Testes may be undescended.
What is the aetiology of the following factors regarding infertility?
Male factors- 30%
Ovulatory disorders- 25%
utrine/peritoneal disease <10%
other factors, including unexplained- 25%
What are some male factors that can cause infertility?
-oligospermia (<20 x10^6)
-abnormal sperm production
-ductal obstruction (vasectomy, inflammation)
-failure to deliver sperm to the female (hypospadias, impotence)
Why would hypospadias lead to infertility?
The urethral opening is on the anterior aspect of the penis, therefore during ejaculation the sperm will not be deposited into the cervix.
How can ovulatory disorders be grouped further?
-hypothalamic pituitary failure
What are some examples of hypothalmaic-pituitary disorders?
-excessive prolactin secretion
-accquired, eg due to anorexia.
What are some examples of hypothalmic-pituitary-ovarian disorders?
-congential adrenal hyperplasia
How could congenital adrenal hyperplasia cause infertility?
excessive secretion of androgens increase the negative feedback, leading to decreased GnRH.
Also can cause PCOS, which increases the risk of infertility.
Give some examples of ovarian failure causing infertility.
-Turners syndrome (45X/ 45XO)
-ovarian tumours-- Chemotherapy
What is polycystic ovary syndrome?
Polycystic ovaries and systemic features due to raised androgen levels.
Cause unknown, thought to have a genetic component.
-can cause anovulation, Amenorrhoea or oligomenorrhhoea.
What is oligomennorrhoea?
infrequent menstrual periods.
What are some clinical features of PCOS?
-hirsuitism (Male hair growth)
-male pattern baldness
-mood swings, depression, anxiety.
What criteria is used for PCOS?
Rotterdam diagnostic criteria.
Need 2/3 of the following.
-polycystic ovaries (>12)
-oligo-ovulation or anovulation
-exclusion of other causes of high anderogen levels.
What are some causes of tubal damage?
-previous pelvic surgery
previous pregnancy (especially ectopic)
-Mullerian developmental abnormality.
What uterine/peritoneal diseases could lead to infertility?
-Ashermans syndrome (fibrosis and or adhesions of the endometrium)
-cervical stenosis (Narrowing of the opening, difficult to sperm to get through)
-cervical hostility (eg female sperm antibodies, infections)
How would you get around a couple in which the female has antisperm antibodies?
inject the sperm directly into her ovaries.
What is endometriosis?
The presence of ectopic endometrial tissue at a site other than the uterus, commonly in the pelvic cavity.
What are some of the features of endometriosis?
-chronic pelvic pain
-infertility (due to scarring and adhesions)
How do you treat endometriosis?
-give the COCP in females who done want to get pregnant.
-those that do want to get pregnant will commonly need IVF.
When would you refer someone for extra investigations concerning infertility?
-When a woman of reproductive age has not conceived after trying for over a year, with no known cause of infertility.
-when a woman has not conceived using arteficial insemmination after 6 months, with no known cuase of infertility.
Under what circumstances do women dealing with infertility get an early referral for further investigations?
-when aged >36.
-When there is a known clinical cause of infertility of predisposing factors.
What investigations would you do on a female whom you suspected infertility?
-luteal phase progesterone (should peak aruond day 21) if menstuating regulalry.
-test for tubal patency.
How do you test for tubal patency?
Inject a dye into the cervix, and it should go up the fallopian tubes and into the pelvic cavity, which can be seen on an x ray. If not, there may be a blockage.
What investigations would you do on a male whom you suspected infertility?
How might a male form antisperm antibodies?
Following trauma there may be a breach of the blood-testes barrier, which allows the sperm to get into the blood.
The blood will recognise the sperrm as forreign and form antibodies to it.
Suggest some treatments for infertility?
DEPENDANT ON CAUSE.
arteficial insemination, IVF.
How could clomifene citrate help infertility?
It is an antagnosist of oestrogen receptors, so will block oestrogen binding. This will reduce the negative feedback, increasing levels of FSH/LH.