Repro 7.2 Contraception and Infertility Flashcards
What are the natural forms of contraception?
Abstinence
Coitus interuputus
Rhythm method
Why is coitus interruptus not 100% effective?
There is some sperm in pre-ejaculate
Why is the rhythm method not 100% effective?
Requires a regular cycle and no woman can be 100% certain when ovulation will occur.
In the rhythm method, what assumptions are made?
Sperm 7 days, ova 1 therefore with a regular 28 day cycle ovulation day will be day 14/15 and the fertile period is days 17-16 so sexual intercourse is avoided at these times
What are the barrier methods of contraception?
Condoms
Diaphragm
Cap
What are the benefits of condoms as a form of contraception?
Readily available
Protect against STI
Effective if used correctly
How does a diaphragm work and what are the disadvantages?
Lies diagonally across the cervix
Needs correct fitting
Does not completely occlude sperm passage but holds sperm in acidic vagina and reduces survival time
How does the cap work as a method of contraception?
Fits across cervix
What is commonly used in conjunction with barrier methods of contraception?
Spermicide
What forms of contraception prevent ovulation?
Combined oral contraceptive pill
Depot progesterone (3 monthly injections)
Progesterone only pill (maybe)
Progesterone implant (maybe)
How can ovulation be prevented?
Inhibit follicular development and by negative feedback to the hypothalamus and pituitary
What forms of contraception inhibit sperm transport?
Female sterilisation Vasectomy Progesterone mediated contraception: Progesterone implant POP Depot progesterone COCP
How do progesterone contraceptives inhibit sperm transport?
Affect cervical mucous -> thick, hostile mucus
Can female sterilisation be reversed?
Yes - 50% success
How is female sterilisation achieved?
Occlude fallopian tubes by clips, rings or ligation
How common is recanalisation following a vasectomy?
rare - 1:300/500
What is a vasectomy?
Vas deferens are divided bilaterally. Ensure ejaculate is free of sperm before relying on it (usually takes approx 20 ejaculations)
What forms of contraception inhibit implantation?
Hormonal (COCP, POP, implant, depot)
Post-coital contraception
IUCD
How do hormonal contraceptives inhibit implantation?
Affect receptivity of the endometrium directly
Absence of corpus luteum further prevents preparation of the endometrium for implantation
What is in post-coital contraception and how does it work?
High dose of combined oestrogen/progesterone or progesterone only
May disrupt ovulation
Blocks implantation
In what time frame is post-coital contraception effective?
Up to 72 hrs after intercourse
IUCD may also be used post-coital
What is IUCD?
Inert or copper containing or progesterone impregnated (mirena coil)
Copper interferes with endometrial enzymes and may also interfere with sperm transport into fallopian tubes
Interferes with implantation
What are the risks of IUCD?
Perforation
Mood swings
Infection (higher risk with copper)
Define infertility.
Failure to conceive within 1 year
How many couples suffer from infertility?
15%
What is the difference between primary and secondary infertility?
Primary - no previous pregnancies
Secondary - previous pregnancies, successful or not
What % of infertility is due to problems in the male, female and unexplained?
Male: 20-25%
Female: 45-60%
Unexplained: 20-30%
What are the potential causes of infertility?
Coital problems
Anovulation
Tubal occlusion
Abnormal/absent sperm production
How common is anovulation and when is it most common?
Cause of 15-20% of fertility problems
Most common at extremes of reproductive life
Where can problems cause anovulation?
Problems in the hypothalamus, pituitary or ovary
What problems in the hypothalamus can cause anovulation?
Hyperprolactinaemia
Weightloss
Exercise
Stress
What problems in the pituitary can cause anovulation?
Pituitary tumours or necrosis
What problems in the ovaries can cause anovulation?
Ovarian failure
Menopause
Radiotherapy
Chemotherapy
How is a diagnosis of anovulation made?
Serum progesterone level in mid-luteal phase (day21 / 7 days before menstruation)
How is the cause of anovulation determined?
Hormone levels:
Menopause or ovarian failure, increased LH and FSH, decreased oestrogen
H/P failure, decreased LH, FSH and oestrogen
PCOS, increased LH/FSH ratio, normal oestrogen
How can ovulation be induced?
Anti-oestrogen drugs - decrease negative feedback to HPA increasing GnRH and FSH
Gonadotrophins - FSH administration
GnRH agonist - pulsatile to mimic normal secretion
What might cause tubal occlusion?
Sterilisation
Scarring from infection or endometriosis
How is tubal occlusion diagnosed?
Laproscopy and dye insufflation - hysterosalpingogram
How can infertility caused by tubal occlusion be treated?
Tubal surgery (reanastomosis) Assisted conception
What might cause abnormal/absent sperm production?
Testicular disease
Obstruction of the ducts (infection, vasectomy)
HPA dysfunction
What is a normal semsn analysis?
Volume >2ml
Sperm count > 20mill/ml
Motility >50%
Morphology >50%
How can infertility due to inadequate sperm be overcome?
Artificial insemination by donor
Intracytoplasmic sperm injection
What i PCOS?
Polycyctic Ovarian Syndrome - A disorder displaying great clinical and biochemical variability. A syndrome of hyperandrogenism and chronic anovulation in which other causes have been ruled out
How does a patient with PCOS present?
Secondary amenorrhoea/infertility
Hirsuitism
Obesity
How does PCOS cause amenorrhoea/infertility?
Related to a lack of pulsatile GnRH release - Many follicle begin to develop but a dominant follicle is not selected to mature. These follicles respond to pituitary hormones by producing an abnormal pattern of oestrogen secretion. Chronic an ovulation is thought to occur because of inappropriate feedback signals from the ovaries to the hypothalamus
Why is hirsuitism a symptom of PCOS?
The syndrome may be characterised biochemically by :H dependent excess androgen production from ovaries and adrenals (perhaps due to an enzyme abnormality)
Why are women with PCOS at increased risk of endometrial malignancy?
Abnormal oestrogen secretion. The endometrium is an oestrogen sensitive tissue; increased oestrogen secretion causes an increase in proliferation of the endometrium, increasing the risk of malignancy
Why does PCOS carry risks of diabetes and cardiovascular disease?
Insulin resistance can form putting them at risk of diabetes and CV disease
What is the treatment of PCOS?
Prevention of long term risks and management of presenting problems.
Metformin
Why does the LH/FSH ration increase in PCOS?
Inhibin also inhibits FSH and LH
Why are there no LH surges in PCOS?
Androgens selectively inhibit LH
What proportion of young couples who have regular unprotected sex might be expected to conceive within a year?
75%
Where are the possible points in the female reproductive tract where problems may lead to infertility?
Failure to ovulate 33%
Fallopian tube problems 22%
Uterine problems 11%
Cervical problems 3%
What factors are assessed in semen analysis?
Sperm count, motility and morphology
What hormone provides evidence menstruation has occurred and when should it be tested for?
Progesterone
Day 21 in serum
Why is it useful to keep a daily record of body temperature on rising in the morning?
Circadian rhythm so must be done at the same time of day
Progesterone increases body temp by 0.4-0.8 degrees a day or 2 after ovulation
What are the 2 most common causes of secondary amenorrhoea and what hormone tests are used to distinguish between them?
Pregnancy - hCG
Menopause - gonadotrophins
What clinicalal sign may indicate a diagnosis of hyperprolactinaemia?
Breast lactation
What properties of cervical mucus facilitate sperm survival and transport?
Lower viscosity and more alkalinity
How might you assess whether cervical sperm transport is disturbed?
Post-coital test - collect cervical mucus soon after copulation
